Columbia ® nitjersiit j>^^ ^^ in tfje Citp ot i^eto gorfe COLLEGE OF PHYSICIANS AND SURGEONS ^^u5o Reference Library Given by Digitized by the Internet Archive in 2010 with funding from Open Knowledge Commons http://www.archive.org/details/preventivemedici1916rose PREVENTIVE MEDICINE AND HYGIENE PREVENTIVE xMEDICINE AND HYGIENE BY MILTON J. ROSENAU PHOFESSOR OF PREVENTIVE MEDICINE AND HYGIENE, HARVARD; DIRECTOR OF THE SCHOOL FOB HEALTH OFFICERS OF HARVARD UNIVERSITY AND THE MASSACHUSETTS INSTITUTE OF technology; formerly DIRECTOR OF THE HYGIENIC LABORATORY, U. S. PUBLIC HEALTH SERVICE, ETC. WITH CHAPTERS UPON SEWAGE AND GARBAGE, BY GEORGE C. WHIPPLE, PROFESSOR OF SANITARY ENGINEERING, HARVARD VITAL STATISTICS, BY JOHN W. TRASK, ASSISTANT SURGEON-GENERAL, V. S. PUBLIC HEALTH SERVICE MENTAL HYGIENE, BY THOMAS W. SALMON, MEDICAL DIRECTOR, NATIONAL COMMITTEE FOR MENTAL HYGIENE, ETC. SECOND EDITION THOROUGHLY REVISED NEW YORK AND LONDON D. APPLETON AND COMPANY 1916 Copyright, 1913. 1916, by D. APPLETON AND COMPANY Printed in the United States of America TO MY WIFE PREFACE TO THE FIRST EDITION This book has been written in response to a demand for a treati.-c based upon modern progress in hygiene and sanitation. The worls: is planned to include those fields of the medical and related sciences which form the foundation of public health work. So far as I know, no other book on the subject covers the broad field considered in this volume. The progress in hygiene and sanitation has been so rapid that the subject of preventive medicine has become a specialty, and its scope has become so broad that the question throughout the making of this book has been rather what to leave out than Avliat to include. The facts here brought together are widely scattered in the literature and many of them are difficult of access; they have been collected for the convenience of tlie student of medicine and the physician, as well as those engaged in sanitary engiuecriiig or public healtli Avork. During twenty-three years of varied experience in public health work it has been Hiy good fortune to have served as quarantine officer, in epidemic campaigns, in epidemiological investigations, and in public health laboratories, at home, on the Continent, and in the tropics. The fruits of these experiences are reflected in this book, which may be taken as representing my personal views gained in the field, in the laboratory, in the classroom, and in administrative offices. It is wellnigh impossible to prevent or suppress a communicable disease without a knowledge of its mode of transmission. This is the most important single fact for successful personal prophylaxis, as well as in the general warfare against infection; therefore;, the com- municable diseases have been grouped in accordance with their modes of transference. Each one of the important communicable diseases is dis- cussed separately in order to bring out the salient points upon which prevention is based. The classification adopted is believed to be unique and should prove helpful to those who are especially concerned in the prevention of infection. The book may be considered in t'wo parts, namely, that which deals vii viii PREFACE ^IX) FIRST EDITION willi ilic person (hygiene) and llial which (h'als with the eiivinjinnent (sanitation). The first part includes tlie prevention of the comniuiiicahlc diseases, venereal prophylaxis, heredity, immunity, eugenics, and similar suhjects. The second part deals with our environment in its relation to health and disease and includes a discussion of food, water, air, soil, disposal of wastes, vital statistics, diseases of occupation, industrial hygiene, school hygiene, disinfection, quarantine, isolation, and other topics of sanitary importance, as well as subjects of interest to health officers. All the important methods used in public health laboratories are described. To have made this book in monographic style with references to authorities for every statement Avould have resulted in an unwieldy work of impractical size and form. The textbook style has therefore been adopted and citation of authorities for facts that are now well estab- lished has been regarded as unnecessary. In this respect it may seem that I have given scant credit to many workers from whose writings I have borrowed results, thoughts, and sometimes words or even sen- tences. At the end of each chapter will be found a list of references to articles or books that I have esjDecially drawn upon, and I desire to acknowledge my obligations to these sources as well as to refer the reader to them for further study of particular subjects. I have also drawn freely upon my own previous writings and those of my co-workers in com23iling this book. The chapter on "Disinfection" is based upon my book entitled : "Disinfection and Disinfectants," published by P. Blaki- ston's Sons & Co., Philadelphia, 1902. I have received generous help from a number of friends and it is a pleasure here to acknowledge especially ni}^ obligation to Dr. David L. Edsall for reading and correcting the chapter on Diseases of Occupa- tions, to Dr. John F. Anderson and Dr. Joseph Goldberger for re- vising the chapters upon Measles and Typhiis Fever, to Prof. George C. Whipple for reading and improving the chapter upon Water, to Charles T. Brues for many suggestions in the section upon insect-borne diseases, and to Prof. W. E. Castle for a similar service with the section on Heredity. Dr. Charles Wardell Stiles has kindly furnished infor- mation concerning the relation of parasites to soil. I also desire to express my obligations to Prof. Arthur I. Kendall, Dr. Harold L. Amoss, Dr. Lewis W. Hackett, Prof. William D. Frost, and Miss Emily G. Philpotts. PREFACE TO FIEST EDITIOX ix It has l)ceii my olgcct to give in this volume the seieiitilic basis upon which the prevention of disease and the maintenance of h«alth must rest. Exact Ivnowledge has taken the place of fads and fancies in hygiene and sanitation; the capable health olticer now possesses facts concerning infections which permit their prevention and even their suppression in some instances. ^lany of these problems are complicated with economic and social difficulties, which are given due consideration, for preventive medicine has become a basic factor in sociology. Boston. M. J. Eose^^au. PREFACE TO THE SECOND EDITION The rapid increase in our knowledge has called for a resetting of this book. I have taken advantage of this to omit some paragraphs and topics, to add others, and to remodel the remainder. The work, m fact, has been largely rewritten. The following subjects have been added : Prevalence of Venereal Diseases, Chancroid, The Schick Eeaction, The Bang Method of Sup- pressing Bovine Tuberculosis, Organization of a Local Tuberculosis Campaign, Tuberculosis Sanatoria and Dispensaries, Emetine, Insecti- cidal Agents Especially for Lice and Fleas, Standardization of Bacterial Vaccines, Sensitized Vaccines, Nuisances, Eoaches, Feeble-mindedness, The Wassermann Test, Belation between Host and Parasite, Essential Requirements for a Safe Milk SupjDly, Butter, Desiccated and Con- densed Milk, Streptococci of Sore Throat, Sodium Fluorid, Hydrofluoric Acid, Cancer Heredity, Tests for Heated Milk, Echinococcus Disease, Carbon Dioxid in Alveolar Air, Sanitary Significance of Odors, Ocular Hygiene, Hydrogen Sulphid, Methane, Accidents in Sewers and Their Prevention, Eeinspiration of Expired Air, Air Washing with Eeference to Ventilation, Goiter, Sanitation of Swimming Pools, Military Hy- giene, Etc. The following chapters have been rewritten in whole or in part : Leprosy, Mushroom Poisoning, Beriberi, Pellagra, Carbon Monoxid, Chlorinated Lime, Vital Statistics (by Trask), Disinfection, Quinin Prophylaxis for Malaria. The subject treated in the chapter on Pre- vention of Mental Diseases in the first edition is now only a relatively small part of the field of mental hygiene. Therefore, in this edition both the title and the scope of this chapter have been changed to Mental Hygiene. An entirely new section on Military Hygiene has been added. The uniform courtesies of the publishers have been appreciated and I also thank those who called my attention to mistakes of commission or omission. I am greatly indebted to Dr. J. Penteado Bill for much xi Xii PRKF.\C!I<] 'IV) ^rilK; SK/'0\I) I'^DITTOX assi.stiiiic(! ill preparing!; lliis cililioii; also lo l)i'. ('has. !>. Spniit, Dr. AVilsoji (I. Smillie and Mi.ss l\Iao ('. Moraii for aid in scciii^^ these j)agcs tliroiigli tlie i^ross. The favorable receptiou which the book lias received is gratifying. Boston. M. J. Eosenau. CONTENTS SECTION I PREVENTION OF THE COMMUNICABLE DISEASES CHAPTER PAGE I.— Diseases Having Specific or Special Prophylactic Measures 1 Smallpox and Vaccination : Historical Note, 1 ; Vaccination, 3 ; Vaccine Virus, 4; Methods of Vaccination, 9; Indices of a Suc- cessful Vaccination, 11; The Immunity, 13; Revaceination, 18; Claims for Vaccination, 20 ; Vaccination of Exposed Persons, 20 ; Dangers and Complications, 21; Government Control of Vaccine Virus, 24; Unity of Cowpox and Smallpox, 25; Compulsory Vaccination, 25 ; Inoculation or Variola Inoculata, 27 ; Prevalence of Smallpox, 29; Epidemiology, 30; Modes of Infection, 30; Resistance of the Virus, 31 ; Smallpox in the Vaccinated and Un- vaceinated, 33 ; The Result of Vaccination in Germany, 33 ; Isola- tion and Disinfection, 36. Rabies : General Considerations, 39 ; Period of Incubation, 40 ; Exit and Entrance of the Virus, 41; The Relative Danger of Bites, 42; Viability, 42; Prophylaxis, 43; The Local Treatment of the Wound, 44; The Pasteur Prophylactic Treatment, 45. Venereal Diseases: Syphilis, 54; Gonorrhea, 58; Chan- croid, 60. Venereal Prophylaxis and Hygiene op Sex: Prevalence, 61; Attitude, 62 ; Education, 63 ; Registration of Cases, 65 ; Con- tinence, 65 ; Personal Hygiene, 66 ; Alcohol, 66 ; Prostitution, 66 ; Medical Prophylaxis, 67; Segregation, 68. Preventable Blindness: Trachoma, 69; Wood Alcohol, 70; Accidents, 70; Ophthalmia Neonatorum, 71; Prevalence, 71; Prevention, 72; Legislation, 74. Tetanus: Etiology, 75; Incubation, 79; Resistance, 79; Pro- phylaxis, 80. II. — Diseases Spread Largely Through the Alvine Discharges 83 Typhoid Fever: General Considerations, 83; Pi-evalenee, 84; Channels of Entrance and Exit, 89; Diagnosis, 89; Bacillus Carriers, 92 ; Resistance of the Virus, 93 ; Typhoid Bacillus in Nature, 94; Modes of Spread, 94; Preventive Typhoid Inocu- lations, 104; Management of a Case so as to Prevent Spread, 108; Summary — Personal Prophylaxis, 110. xiv ' CONTENTS CHAPTER Cholera: General Considerations, 112; The Cause and Con- tributing' Causes of Cholera, 113; Diag-nosis, 114; Modes of Transmission, 115; Immunity and Prophylactic Inoculations, 118; Quarantine, 119; Personal Prophylaxis, 120; Summary — Prevention, 120. Dysentery: Classification, 121; Mode of Transmission, 122; Resistance, 123; Immunity, 123; Prophylaxis, 124. Hookworm Disease: Distribution, 125; Varieties of Hook- worm, 126; Modes of Transmission, 127; The Parasite, 127; Immunity, 130 ; Resistance of the Parasite, 130 ; Prevention, 130 ; Collateral Benefits, 132. III. — Diseases Spread Largely Through Discharges from the Mouth and Nose 134 Tuberculosis : General Considerations, 134 ; The Difference be- tween Human and Bovine Tubei'cle Bacilli, 135; Bovine Tuber- culosis in Man, 136 ; Modes of Infection, 141 ; Immunity, 147 ; Resistance of the Virus, 150; Prevention, 150; Segregation, Sanatoria, 152; Personal Prophylaxis, 153; Tuberculosis in Children, 156; Bovine Tuberculosis, 157; The Bang Method of Suppressing Bovine Tuberculosis, 157; Organizing a Local Tuberculosis Campaign, 158; Summary, 158. Diphtheria: General Considerations, 159; Modes of Trans- mission, 160; Bacillus Carriers, 162; Resistance, 165; Immunity, 165 ; The Schick Reaction, 166 ; Prevention, 166 ; Personal Pro- phylaxis, 169; Prevention of Post-diphtheritic Paralysis, 169; Prevention of Serum Sickness, 170; Historical Note, 171. Measles: General Considerations, 172; Immunity, 174; Resist- ance of the Virus, 174; Modes of Transmission, 175; Prevention, 176. Scarlet Fever: General Considerations, 178; Modes of Trans- mission, 179; Immunity, 182; Prophylaxis, 182. Whooping Cough : Modes of Transmission, 184 ; Immunity, 184 ; Prevention, 185 ; Mortality, 186. Mumps, 187. Pneumonia: General Considerations, 188; Modes of Trans- mission, 189; Resistance of the Virus, 189; Immunity, 190; Prevention, 190. Influenza: Immunity, 192; Modes of Transmission, 193; Prophylaxis, 193. Common Colds: General Considerations, 194; Prevention, 195. Cerebrospinal Fever: General Considerations, 197; Preven- tion, 199. CONTENTS XV :hapter page IV. — Insect-Borne Diseases ........ 201 General Considerations, 201. Insecticides: Preparation of the Room for Fumigation, 208; The Relative Efficiency of Insecticides, 209; Sulphur, 211; For- " maldehyd, 212; Pyrethrum, 213; Phenol-camphor, 214; Hydro- cyanic Acid Gas, 215; Bisulphid of Carbon, 216; Petroleum, 217; Arsenic, 218. Mosquitoes : Life History and Habits, 221 ; The Destruction of Mosquitoes, 223; Malaria, 228; Yellow Fever, 236; Dengue, 244; Filariasis, 246. Flies: General Considerations, 247; Life History of Musca Domestica, 249 ; Life History of Stomoxys Calcitrans, 250 ; Flies as Mechanical Carriers of Infection, 250; Suppression, 254; Sleeping Sickness, 256; Pappataci Fever, 261. Fleas: General Considerations, 261; Pulicides, 264; Relation of Plague to Rats and Fleas, 264. Rats and Other Rodents: General Considerations, 267; Breed- ing and Prevalence, 268 ; Migration, 269 ; On Ships, 270 ; Food, 270; Habits, 270; Rat-Bite Fever, 271; Plague in Rats, 271; Rat Leprosy, 273; Trichinosis, 273; Other Parasites, 273; Economic Importance, 273 ; Suppression, 274 ; Squirrels, 279 ; Plague, 281. Ticks: General Considerations, 287; Texas Fever, 288; Rocky Mountain Spotted Fever, 289; Relapsing Fever, 292. Lice: General Considerations, 294; Typhus Fever, 295. Bedbugs: General Considerations, 299; The Suppression of Bedbugs, 300; Kala-Azar, 301. Roaches, 301. References, 303. V. — Miscellaneous Diseases 304 Infantile Paralysis: General Considerations, 304; Resistance of the Virus, 306 ; Immunity, 306 ; Modes of Transmission, 306 ; Prevention, 308. Chickenpox, 309, Glanders: General Considerations, 310; Diagnosis, 311; Pre- vention, 314. Anthrax: Resistance, 316; Immunity, 316; Prevention, 316. FOOT-AND-MoUTH DiSEASE, 317. Malta Fever: Modes of Transmission, 319; Goats' Milk and Malta Fever, 321; Resistance, 322; Prevention, 322. Leprosy: General Considerations, 322; Immunity, 324; Rat Leprosy, 325; Modes of Transmission, 326; Prevention, 329; Specific Prevention, 330; References, 330. xvi CONTENTS CHAPTER PAGE VI. — Mental IIygjkne (By Tliomas W. Salmon, M.lX) . . . 331 General Considerations, 331 ; Importance of the Problems, 332 ; Heredity, 334; Alcohol, 33S; Other Exogenous Poisons, 342; • Endogenous Poisons, 342; Syphilis, 342; Other Infections, 346; Head Injuries, 347; Mental Causes, 352; Economic Factors, 352; Immigration, 353. Agencies Available for the Application of Preventive Measures: Hospitals for Mental Disease, 354; Boards of Ad- ministration and Supervision, 356; Public Health Authorities, 356; Educational .Authorities, 356; National and Local Societies for Mental Hygiene, 357. Conclusion, 358. References, 359. VII. — Some General Considerations . 362 Sources of Infection, 362; Modes of Transference, 363; Carriers, 364; Missed Cases, 365; Channels of Infection, 366; "Con- tagious" and "Infectious," 366; Epidemic, Endemic, Pandemic, and Prosodemic, 367 ; Fomites, 368 ; The Management of an Epi- demic Campaign, 368. Quarantine : Maritime Quarantine, 372 ; Quarantine Pro- cedures, 376; The Bill of Health, 377; The Equipment of a Quarantine Station, 377; Qualifications of the Quarantine Officer, 378; Disinfection of Ships, 378; Cargo, 382; Ballast, 382; Foreig-n Inspection Service, 382; National versus State Quarantine, 383; Interstate Quarantine, 383. Isolation, 384. Nuisances, 386. References, 387. SECTION II IMMUNITY, HEREDITY AND EUGENICS I. — Immunity . . 389 General Considerations, 389 ; Mechanism and Theories of Immu- nity, 390 ; Natural Immunity, 393 ; Acquired Immunity, 394 ; Mixed Immunity, 395; Hoav Active Immunity May Be Acquired, 395 ; Standardization of Bacterial Vaccines, 398 ; Specificity, 398 ; Local and General Immunity, 400; Bacillus Carriers or Immu- nitas Non Sterilans, 401 ; Latency, 403 ; Lowered Resistance, 403 ; Relation between Host and Parasite, 407; Ehrlieh's Side-Chain Theory of Immunity, 408; Antitoxic Immunity, 413. Toxins, 414. CONTEI^TS xvii CHAPTER PAGE Antitoxins: General Considerations, 418; Gibson's Method of Concentrating Diphtiieria Antitoxin, 423; Dried Antitoxin, 424; Mode of Action, 424. Endotoxins, 425. Tetanus Toxin : General Considerations, 426 ; Mode of Action, 429. Tetanus Antitoxin, 430. Standardization of Antitoxic Sera: The Standardization of Diphtheria Antitoxin, 431; Standardization of Tetanus Anti- toxin, 433, Phagocttosis, 436. Opsonins: The Opsonic Index, 440. Lysins: Pfeiffer's Phenomenon, 441. Hemolysis, 443. Cytotoxins, 445. The Bordet-Gengou Phenomenon — Fixation of Complement : The Wasserman Reaction, 446. The Neisser-Wechsberg Phenomenon or Deviation of the Complement, 449. Precipitins : General Considerations, 450 ; Tests for Blood, 452. Agglutinins, 454. Anaphylaxis : General Considerations, 457 ; Examples of Ana- phylaxis, 458 ; Experimental Serum Anaphylaxis, 458 ; Speci- ficity, 460; Sensitization by Feeding, 462; Maternal Transmis- sion, 462; Serum Anaphylaxis in Man, or Serum Sickness, 462; Hypersusceptibility and Immunity Produced by Bacterial Pro- teins, 465 ; Relation of Anaphylaxis to Protein Metabolism, 465 ; Relation of Anaphylaxis to Endotoxins, 466; The Relation of Anaphylaxis to Tuberculosis, 466 ; Relation of Anaphylaxis to Vaccination, 467; Relation of Anaphylaxis to Hay Fever, 468; Other Practical Relations of Anaphylaxis, 468. References, 469. II. — Heredity and Eugenics 470 General Considerations, 470; Feeble-minded Idiots, Imbeciles and Morons, 471; Prevention of Propagation of Defectives, 472; Statistics of Defectives, 474; Degenerate Families, 476. Eugenics, 479. Principles of Heredity: Variation, 481; Darwin's Theory, 482; Mutation, 483; De Vries — Discontinuous Evolution, 483; Weismann's Views, 484; Mendel's Law, 485; Atavism or Rever- sion, 488; Gallon's Law of Filial Regression, 490. The Cell in Heredity, 490. Biometry, 492. xviii CONTENTS CHAPTER PACK Heredity Versus Environment, 490. Immunity Gained Through Inheritance, 497. III. — The Hereditary Transmission of Disease .... 498 General Considerations, 498; The Microbie Diseases, 500; Hereditary Transmission of a Tendency to a Disease, 501 ; Tuber- culosis, 502; Syphilis, 502; The Wassermann Reaction, 503; Cancer, 504; Deaf -Mutism, 505; Albinism, 506; Color-blindness, or Daltonism, 507; Hemophilia, 508; Gout, 508; Braehydactylism, 508; Polydactylism, 509; Myopia, 509; Cataract, 509; Retinitis Pigmentosa, 509 ; Diabetes Mellitus, 509 ; Orthostatic Albumin- uria, 509; Alcoholism, 510; Epilepsy, 511; Huntington's Chorea, 512 ; Friedreich's Disease — Hereditary Ataxia, 513 ; Insanity, 514. References, 515. SECTION III FOODS I. — General Considerations 516 The Uses op Food, 518. Classification of Foods: Physical Properties, 519; Sources, 519; Composition and Function, 520; Classification, 520. The Amount of Food : Excessive Amounts, 521 ; Insufficient Food, 521; Unbalanced Diets, 522; Salts in the Diet, 523. Adulteration of Food, 523. Decomposed Foods : Fermentation and Putrefaction, 527 ; "Ptomain" Poisoning, 528. Preservation op Foods: Cold, 533; Drying, 536; Salting and Pickling, 538; Jellies and Preserves, 539; Smoking, 539; Chem- ical Preservatives, 542. The Preparation of Food : Cooking, 550 ; Methods of Cooking, 552. II. — Animal Foods: Milk 553 Milk : General Considerations, 553 ; Composition, 554 ; Milk Standards, 558; Ferments or "Life" in Milk, 559; "Leukocytes" in Milk, 561 ; The Excretion of Drugs in Milk, 562 ; The Differ- ences between Cow's Milk and Woman's Milk, 562; Classifieation of Milk, 563; The Decomposition of Milk, 565; Bitter Milk, 567; Colored Milk, 568 ; Adulterations of Milk, 568 ; Dirty Milk— The Dirt Test, 568; Bacteria in Milk, 569; The Germicidal Property of Milk, 571; Diseases Spread by Milk, 571; The Character of Milk-borne Epidemics, 578; Desiccated Milk, 579; Condensed Milk, 579; Fresh Milk Products, 579; Butter, 580; Inspection, 582; Pasteurization, 582; The Effect of Heat upon Milk, 586. CONTENTS xix CHAPTER PAGE The Bacteriological Examijstation of Milk : The Number of Bacteria, 588; The Kinds of Bacteria, 589. Microscopic Examination: The Stewart-Slack Method, 591; The Doane-Buckley Method, 591; The Prescott-Breed Method, 591. Chemical Analysis of Milk : Total Solids, 592 ; Determination of Total Solids, 592 ; Determination of Fats, 593 ; Determination of Milk Sugar, 596; Determination of Proteins, 597; Water, 598; Reaction, 599; Specific Gravity, 600; Heated Milk, 601. References, 603. III. — Animal Foods : Meat, Fish, Eggs, Etc 605 Meat: Structure and Composition of Meats, 605; Nutritive Value of Meat, 606; Sources of Meat, 607; The Recognition of Spoiled Meat, 608; Prevention, 608; Meat Preservatives, 608. Meat Inspection : General Considerations, 609 ; The Abattoir, 610; Qualifications of a Meat Inspectoi', 612; The Freibank or Three-class Meat System, 612; Emergency Slaughter, 613; Methods of Slaughter, 613; The United States Meat Inspection Law, 614 ; Ante-mortem Inspection, 615 ; Post-mortem Inspection, 615. Meat Poisoning: General Considerations, 618; Paratyphoid Fever, 623; Botulism or Sausage Poisoning, 626; Animal Para- sites, 629. Fish: Physiological Fish Poisoning, 635; Bacterial Poisons, 635; The Fish Tajieworm, 635. Shellfish : General Considerations, 636 ; Mussel Poisoning, 639; Miscellaneous, 640. Bob Veal, 640. Eggs, 641. IV.— Plant Foods „ ... 644 Poisoning from Plant Foods : Ei-gotism, 644 ; Lathyrism, 645 ; Mushroom Poisoning, 645; Potato Poisoning, 648; Beriberi, 649; Pellagi^a, 653. References, 659. SECTION IV AIR I. — Composition op the Air 661 General Considerations, 661 ; Oxygen, 663 ; Nitrogen, 655 ; Argon, 655; Ozone, 655; Hydrogen Peroxid, 667; Ammonia, 667; Min- eral Acids, 668; The Amount and Function of COg in Alveolar XX CONTIvXTS CHAPTER PAGE Ail-, (if)!); ('()„ MS an Index of Vitiation, (i71; Methods for Deter- mining' Carbon Dioxid, (572 II. — Pressure, Temperature and Humidity 681 Pressure: Normal Atmospheric Pressure, 681; Diminished Atmospheric Pressure, 681 ; Increased Atmospheric Pressure, 683; Barometers, 684. Movements of the Atmosphere, 685. Temperature of the Air: General Considerations, 687; Meth- ods of Recording Temperature, 688. Humidity: Aqueous Vapor, 689; Methods of Detennining Humidity in Air, 693; Relation of Humidity and Temperature to Health, 697; Effects of Wann Moist Air, 700; Effects of Cold Damp Air, 700; Effects of Warm Dry Air, 701, III. — Miscellaneous 703 Odors, 703; Light, 705; Electricity, 707; Radioactivity, 708; . Smoke, 708; Fog, 711; Dust, 712; Dust and Disease, 713; Meth- ods for Examining Dust, 715. IV. — Bacteria and Poisonous Gases in the Air .... 716 Bacteria in the Air : General Considerations, 716 ; Methods for Determining Bacteria in the Air, 717; Air and Infection, 719. Poisonous Gases in the Air: Carbon Monoxid, 721; Illumi- nating Gas, 723; Other Gases in the Air, 726. Sewer Gas : Bacteria in Sewer Aii', 729 ; Accidents in Sewers, 730; Illustrative Cases of Death Attributed to Sewer Gas, 731; Prevention of Accidents in Sewers, 733; Ventilation of Sewers, ' 733. V. — Fresh and Vitiated Air 735 The Benefits of Fresh Air, 735. The Effects of Vitiated Air: General Considerations, 735; The Effects of Increased Carbon Dioxid and Diminished Oxygen, 737 ; PoisoHS in the Expired Breath, 738 ; Physical Changes in the Air, 740; Reinspiration of Expired Air, 742. Summary, 744. VI. — Ventilation and Heating 746 Ventilation : General Considerations, 746 ; Air Washing, 748 ; Recirculation, 748; Vitiation by Respiration, 749; Dead-Space Air, 750; Factor of Safety, 750; The Amount of Air Required, 750; Standards of Purity and Efficiency of Ventilation, 753; The Size and Shape of the Room, 754; Inlets and Outlets, 756; CONTENTS xxi CHAPTER PAGE External Ventilation, 758; Natural Ventilation, 758; Mechanical Ventilation, 762. Heating: General Considerations, 762; Open Fires, 763; Franklin Stoves, 764 ; Open Gas Heaters, 764 ; Hot-air Furnaces, 764; Hot-water and Steam Pipes, 765; Electric Heating, 765; The Cooling- of Rooms, 765. References, 765. SECTION V SOIL I. — General Considerations 767 Classification of Soils, 768; Surface Configuration, 768; Com- position of the Soil, 769; Physical Properties, 770; Soil Air, 771; Soil Water, 772; The Nitrogen Cycle, 773; The Carbon Cycle, 777. II. — Soil and Its Relation to Disease 778 Bacteria in Soil, 778; Pollution of the Soil, 779; Dirt, 780; Cleanliness, 781; The Influence of the Soil upon Health, 782; Diseases Associated with the Soil, 782. SECTION VI WATER I. — General Considerations 789 Composition, 789; Classification of Water, 790; Pi'operties of Water, 791 ; The Uses of Water in the Body, 791 ; The Amount of Water Used and Wasted, 792 ; Double Water Supplies, 79 Sources of Water: Rain Water, 797; Surface Waters, 800; Ground Water, 806. Sources and Nature of Water Pollution and Infection: General Considerations, 816; Simple Tests to Determine Nature of Pollution, 817; The Interstate Pollution of Streams, 818; The Care, of Catchment Areas, 819. II. — Sanitary Analysis of Water . 821 Standard Methods, 821. Odors and Taste: General Considerations, 823; Method of Determining Odor, 826; Prevention and Removal of Tastes and Odors, 827. Color: General Considerations, 828; Method for Estimating Color, 829. xxii CONTENTS CHAPTER PAGE Turbidity: General Considerations, 829; Methods for Estimat- ing Turbidity, 831. Reaction, 831. Total Solids: Method, 833. Hardness: General Considerations, 834; Methods, 836. Organic Matter: Free Ammonia, 837; Albuminoid Ammonia, 841; Nitrites, 842; Nitrates, 844. Chlorin: General Considerations, 840; Determination of Chlorin, 847. Oxygen: Oxygen Consumed, 848; Dissolved Oxygen, 850. Iron: General Considerations, 852; Iron Pipes, 852, Lead : Tests, 853. Expression of Chemical Results, 854. III. — Microscopical Examination op Water . . . . . 855 The Sedgwick-Rafter Method, 855; Significance of the examina- tion, 857. Bacteriological Examination: The Number of Bacteria in Water, 858; Method for Determining the Number of Bacteria in Water, 860; Kinds of Bacteria in Water, 861. IV, — Interpretation of Sanitary Water Analysis .... 866 General Considerations, 866; Allowable Limits, 867; Illustrative Analyses Interpreted, 869. V. — The Purification of Water 878 Nature's Method of Purifying Water: General Considera- tions, 878 ; Evaporation and Condensation, 879 ; Self -purification of Streams, 879; Storage in Lakes and Ponds, 881. Distilled Water, 882. Boiled Water, 882. Filters: Slow Sand Filters, 883; Mechanical Filters, 890; Household Filters, 894; Scrubbing or Roug-hing Filters, 895; Screening, 895. Storage, 896. Sedimentation, 896, Chemical Methods of Purifying Water: Ozone, 897; Chlori- nated Lime — Bleaching Powder or "Chlorid of Lime," 900; Chlorin, 905; Permanganate of Potash, 906; Alum or Sulphate of Aluminum, 906; Sulphate of Iron and Lime, 908; Metallic Iron: The Anderson Process, 909; Copper Sulphate, 909. Ultraviolet Rays, 910. CONTENTS xxiii ClJAPTEIt ■ PAGE VI. — Water and Its Relation to Disease ...... 912 General Considerations, 912. The Mills-Reincke Phenomenon, 913. Non-Specific Diseases Due to Water: General Considera- tions, 915; Goiter, 916; Lead Poisoning, 920. Specific Diseases Due to Water: General Considerations, 923; Cholera, 925; Typhoid Tever, 932; Dysentery, 944; Diar- rhea, 945; Animal Parasites, 946. The Sanitation of Swimming Pools, 947. Ice: General Considerations, 947; Natnral Ice, 950; Manu- factured Ice, 950; Ice and Disease, 952. References, 953. SECTION VII SEWAGE DISPOSAL By George C. Whipple General Considerations: Importance of Speedy Removal of Fecal Matter, 955; Dry Earth System, 956; Water Carriage System, 956; Separate atid Combined Systems, 957; Quantity of Sewage, 958; Composition of Sewage, 958; Ventilation and Flushing of Sewers, 960. Stream Pollution : Sewage Disposal by Dilution, 960 ; Hygienic Aspects of Stream Pollution, 962; Protection against Pollution, 963 ; Fundamental Principles of Sewage Treatment, 964 ; Prepar- atory Processes, 964; Purification Processes, 966; Finishing Processes, 971; Choice of Methods, 972; Relative Bacterial Effi- ciency of Different Processes, 972 ; Management of Sewage Treat- ment Works, 973 ; Treatment Plants as Nuisances, 973 ; Nuisances Caused by Trade Wastes, 974. Cooperative Sanitation, 976. The Rural Problem of Sewage Disposal, 976. References,, 979. SECTION VIII REFUSE DISPOSAL By George C. Whipple General Considerations, 981; Incineration Plants, 984; Reduction Plants, 985; Feeding Garbage to Hogs, 986; Collection of Gar- bage, 986; References, 986. xxiv ('0\"IM<:X'l\S CHAI'TIOK SECTION IX VITAL STATISTICS By John W. Tha.sk, M. D. General Considerations, 987. Vital Statistics: Definition, flS.S; Development, 9Suilding, 1079; The School- room, 1080 ; The School Furniture, 1081 ; Posture, 1085 ; Lighting, 1085 ; Ventilation and Heating, 1086 ; Water-closets and Urinals, 1088 ; Cloak-rooms, 1088 ; Cleanliness, 1088 ; Medical Inspection of Schools, 1089; The Communicable Diseases of Childhood, 1092; Closing Schools on Account of Epidemics, 1092; The Eyes; The Ears; The Teeth; Nose and Throat, 1094; Diseases of the Skin, 1095; Nervous Diseases and Mental Defects, 1096; Vaccination, 1097 ; References, 1097. SECTION XII DISINFECTION I. — General Considerations 1099 Disinfection, 1099; Nature's Disinfecting Agents, 1101; Clean- liness, 1101 ; Antibiosis and Symbiosis, 1102 ; When and Where to Disinfect, 1102; Qualifications of the Disinfector, 1103; Con- trols, 1103; Disinfection Must P)e in Excess of Requirements, 1103; The Ideal Disinfectant, 1104; Terminal Disinfection, 1104; Penetration, 1105; Albuminous Matter, 1105; Time, 1106; Tem- perature, 1106 ; Emulsions and Solutions, 1107 ; Dilution, 1107 ; Reaction, 1108 ; How the Bacteria are Killed, 1108 ; The Choice of Germicide, 1108. The Standardization of Disinfectant: General Considera- tions, 1109; Methods of Standardizing Disinfectants, 1110; Car- bolic Coefficient, 1111. II. — Physical Agents of. Disinfection 1119 Sunlight, 1119; Ultraviolet Rays, 1119; Electricity, 1121; Burn- ing, 1121; Dry Heat, 1121; Boiling, 1122; Steam, 1122. xxvi CONTENTS CHAPTKB PAGE III. — Chemical Agents of Disinfioction 1132 Gaseous Disinkkctants — Fumioation : Pi'cpai'nlion nl' \\u; Room, 1132; rormaldeliyd Gas, IVS.i; Sulphur Dioxid, ll'.iH; Hydrocyanic Acid Gas, 1144; Chlorin, 1144; Oxygen, 1146; Ozone, 114G. Liquid Disinfectants : General Considerations, 1146 ; Methods of Using Chemical Solutions, 1147 ; Bichlorid of Mercury, 1147 ; Coal Tar Creosote, 1149; Carbolic Acid, 1150; Phenol, 1151; The Cresols, 1152; Lysol, 1153; Creolin, 1153; Aseptol, 1153; Asaprol, 1153; Sanatal, 1153; Solveol and Solutol, 1154; Naphthols, 1154; Naphthalene, 1154; Formalin, 1154; Potassium Permanganate, 1155; Lime, 1156; Antiformin, 1160; Bromin and lodin, 1161; Ferrous Sulphate, 1161; Sulphate of Copper, 1161; Chlorid of Zinc, 1161. Acids, 1161. Alcohol, 1162. Soaps, 1162. Convenient Formulae for Disinfecting Solutions : Bichlorid of Mercury, or Corrosive Sublimate, 1164; Formalin, 1164; Milk of Lime, 1164; Carbolic Acid, 1164; Chlorinated Lime, 1165. IV- — Methods of Disinfection 1166 Air, 1166; Rooms, 1166; Stables, 1168; Railroad Cars, 1169; Feces, 1171; Sputum, 1173; Bed and Body Linen, 1174; Books, 1174; Cadavers, 1175; Thermometers, 1176; Wells and Cisterns, 1176. SECTION XIII MILITARY HYGIENE General Considerations 1177 Recruits and Recruiting : General Considerations, 1178 ; Age, 1179; Character and Mental Condition, 1180; Height, Weight and Chest Measurements, 1180 ; Records, 1181 ; Vaccination, 1181; General, 1181. Diseases of the Soldier : General Considerations, 1182. Organization of the Medical Department : General Consid- erations, 1183; Duties, 1186. Rations: General Considerations, 1189; Garrison Ration, 1189; Reserve Ration, 1191; Haversack Ration, 1191; Travel Ration, 1191; Filipino Scout Ration, 1192; French Ration, 1192; Emer- gency Ration, 1193; German Iron Ration, 1193; Japanese Iron Ration, 1193. CONTENTS xxvii HAPTER PAGE Sanitation in Camp and on the March 1193 Personal Hygiene of the Soldier, 1194; Tlie March, 1194; Dis- cipline and Sanitation, 1195. Equipment: General Considerations, 1197; First-aid Packet, 1199; Clothing, 1199. Physical Training, 1203. Sanitation of Barracks and Permanent Camps, 1203. Sanitation of Trenches, 1204. Drinking Water, 1205; Boiling, 1205; Distillation, 1206; Fil- tration, 1206; Chemical Disinfection, 1206. Disposal op Excreta, 1207; Latrines, 1207. Disposal of Garbage, 1207. References, 1208. Index 1211 LIST OF ILLIJSTEATIONS FIGURE 1. Vaccination scars ......... 2. Tiie course of the eruption ....... 3. Vaccinia: course of the eruption from the fourth to the ninth day 4. Vaccinia: course of the eruption from the tenth day . 5. Smallpox in Liverpool during ten years (1902 to 1911) 6. Course of vaccination and revaccination ..... 7. Smallpox mortality per 100,000 of population in Breslau . 8. Smallpox mortality per 100,000 of population in Vienna . 9. Smallpox mortality per 100,000 of population in Prussia . 10. Smallpox mortality per 100,000 of population in Austria . 11. Chart showing relation of enforcement of muzzling law to prevalence of rabies in Great Britain ...... 12. Influence of public water supplies on the typhoid fever death rate 13. Immediate and striking effect of purifying a badly infected water supply upon the typhoid situation . 14. Abrupt reduction in death rates from typhoid fever incident to water jjurification in four American cities .... 15. Hookworm, natural size ....... 16. Hookworm embryo ........ 17. Chart showing the decline in the death rate from tuberculosis 18. Chart computed from U. S. Census Eeport to show how the opening of schools in autumn increases diphtheria . 19. A South African blood-sucking fly (Pangonia), illustrating long pro boscis to pierce heavy fur of certain animals 20. Example of sealing doors for purpose of fumigation 21. Anopheles punctipennis ...... 22. Stegomyia calopus (female) ..... 23. Head of stegomyia calopus (male) .... 24. Eggs of stegomyia calopus ..... 25. Larva of stegomyia calopus. Kespiratory syphon of culcx to the right 26. Pupa of stegomyia calopus ..... 27. House fly showing proboscis in the act of eating sugar 28. Eggs of house fly as laid in a mass .... 29. Eggs of house fly ..... • 30. Larvae of house fly ..... ■ 31. Puparium of house fly ..... . 32. Stable fly PAGE 11 12 14 15 16 19 84 35 37 38 43 95 97 98 127 127 151 160 203 209 230 238 239 240 240 241 247 248 248 249 250 250 XXX FIGURE 33. 34. 3.5. 36. 37. 38. 39. 40. LIST OF lLLi:STKAT10NS 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. 59. 60. 61. 62. 63. 64. 65. 66. 67. Head showing proboscis, stonioxys calcitrans Wing of stable fly . The "little house fly" . Wing of house fly showing liow it carries dust particles The Hodge fly trap on a garbage can Tsetse fly Various gnats .... The Indian rat flea .... 41. The common rat flea of Europe and North America 42. The human flea .... A squirrel flea .... General scheme for testing plague rat infection, City of Manila . Isolated plague-infested center, Manila, P. I. . The Texas fever tick ......... 47. Eocky Mountain spotted fever tick ....... 48. The bedbug Diagrammatic representation of complement fixation The cell with its various combining groups or side chains known as receptors .......... The toxin molecule: showing the haptophore (combining) group, and the toxophore (poison) group ....... The first stage of antitoxin formation : a toxin molecule anchored to a receptor ........... The second stage : continued stimulation causes a reproduction of receptors .......... Third stage: the receptors beginning to leave the cell Fourth stage: the receptors have left the cell and float free in the blood-antitoxin ......... The neutralization of a toxin by antitoxin; the free receptors in the blood have united with the toxin-antitoxic immunity The second order of immunity, showing complement and immune body The third order of immunity, showing an immune body having two affinities ......... Diagram illustrating deviation of complement History of the family zero ....... History (condensed and incomplete) of three markedly able families Wilson's theory of inheritance modified by Lock Diagram showing the course of color heredity in the Andalusian fowl, in which one color does not completely dominate another Diagram showing the course of color heredity in the guinea-pig, in which one color (black) completely predominates another (w^hite) Model to illustrate the law of probability or ' ' chance " . Normal curve ..........' Family history showing deaf-mutism ...... PAGE 251 251 252 253 255 257 259 262 262 263 265 285 286 289 290 299 314 410 410 411 411 411 412 412 413 413 450 477 480 484 487 487 493 494 506 LIST OF ILLUSTRATIONS xxxi FIGUBE PAGE 68. Family history showing polydactylism 69. Family history showing Huntington's chorea 70. Family history showing feeblemindedness 71. Unsanitary surroundings of a cow barn . 72. Conditions under which it is difficult to cleanse and disinfect milk bottles and milk pails ....... 73. A dark, poorly ventilated cow shed, difficult to keep clean 74. Automatic temperature recorder for pasteurizers 75. Strauss home pasteurizer ....... 76. Trichinella spiralis. Entire life cycle in each host . 77. Taenia solium, the pork or measle tapeworm .... 78. Beef tapeworm ......... 79. Dibothriocephalus latus, the fish tapeworm .... 80. Sections through seeds of rice, wheat and corn 81. Portable Haldane apparatus for small percentages of carbon dioxid 82. Petterson-Palmquist apparatus 83. Wolpert air tester . 84. Fitz air tester 85. Diagram showing absolute humidity 86. Sling psychrometer 87. Eelative humidity table . 88. Dew-point apparatus 89. Table showing density of smoke, in accordance with the Eingelmann chart, which may be emitted from the various classes of stacks in Boston, Mass., and the duration of such emission 90. Magnus aspirator ....... 91. Double aspirator ....... 92. The position of inlets and outlets, and their relation to the air currents in a room ......... 93. Window ventilator ......... 94. Diagrammatic sketch of various provisions for ventilation 95. The nitrogen cycle ......... 96. The nitrogen cycle in diagrammatic vertical section . . 97. Ground water ......... 98. Usual method of pollution and even infection of wells 99. Proper construction of a well ....... 100. Popular idea of how wells become infected from surface pollution 101. Depression of the ground water level by pumping and tendency to draw nearby pollution from the soil or cesspool 102. In a limestone formation it is difficult to tell anything about the source of water obtained from a well .... - 815 103. Algae commonly found in water ....... 824 104. Algae commonly found in water ,,...•• 825 510 512 514 565 569 578 584 585 629 632 633 636 650 674 676 679 680 in grains at different temperatures 690 694 695 696 710 718 718 757 760 761 774 775 807 811 812 813 814 xxxii LIST OF ILLUSTRATIONS FIGURE PAGE 105. The oil droplets in a diatom ........ 826 106. Graduated cylindrical funnel and concentrating attachment used in the Sedgwick-Rafter method ....... 856 107. Diagram illustrating the character of ground water in relation to soil pollution, to assist in the interpretation of a sanitary analysis . 868 108. Diagram showing location of samples ...... 877 109. Section of an English filter bed ....... 884 110. The arrangement of a slow sand filter ...... 885 111. Diagram illustrating "loss of head" ...... 888 112. An ozonizer ............ 898 113. An installation for treating water with ozone ..... 899 114. Asiatic cholera and the Broad Street pump, London, 1854 . . . 927 115. Asiatic cholera and the Broad Street well, London, 1854 . . . 929 116. Map showing Hamburg water supply ...... 931 117. Change in water supply ......... 934 118. Mean death rates from typhoid fever, 1902 to 1906, in 66 American cities and 7 foreign cities ....... 935 119. Map of Plymouth, Pa., in 1S85 ....... 938 120. Map showing water supply of Ashland, Wis. ..... 940 121. Cross section of septic tank . . ... . . . . 965 122. Typical section of an Imhoff tank ....... 965 123. Chemical precipitation plant at Worcester, Mass., outlet . . . 967 124. Triple contact beds at Hampton, England ..... 967 125. Cross section of intermittent sand filter ...... 968 126. Inclined screen operated by water wheel, Birmingham, England . . 968 127. Cross section of contact bed ........ 969 128. Typical section of a sprinkling filter ...... 969 129. Trickling filter at Birmingham, England ...... 970 130. Septic tank and chemical precipitation tanks at Eochdale, England . 974 131. Intermittent sand filtration bed at Brockton, Mass. .... 977 132. Filter bed with sand ridged for winter operation at Brockton, Mass. 977 133. Discharge of sewage upon a filter bed at Brockton, Mass. . . . 978 134. Digestion process of garbage reduction ...... 982 135. A simple type of garbage incinerator ...... 983 136. Cobwell process of garbage reduction, New Bedford, Mass. . . 985 137. Births (including stillbirths), persons married and deaths (excluding stillbirths) registered per 1,000 population per annum — Michigan, 1871 to 1912 995 138. Smallpox — number of cases notified per annum in Michigan, 1883 to 1912 1002 139. Smallpox — number of cases notified per annum for each death regis- tered, Michigan, 1883 to 1912 1003 140. Scarlet fever — number of eases notified per annum for each death registered, Michigan, 1884 to 1912 1006 LIST OF ILLUSTRATIONS XXXlll PAGE FIGURE 141. Measles — number of cases notified per annum for each death regis- tered, Michigan, 1890 to 1912 1010 142. Diphtheria — number of cases notified per annum for each death regis- tered, Michigan, 1884 to 1912 1011 143. Births and deaths (exclusive of stillbirths) per 1,000 population per annum, registered in Massachusetts, 1871 to 1911 . . . 1023 144. Eed oxid of lead and litharge being mixed in the manufacture of storage batteries ......... 1037 145. An effective dust-removing system in the boot-and-shoe industry. Edge trimming ......... 1041 146. System of hoods and ventilators to carry off the fumes from the furnaces in a foundry ........ 1045 147. A Avorker with lead oxid, showing respirator to protect himself against the poisonous dust ......... 1051 148. The stone industry ......... 1055 149. Workmen exposed to zinc fumes in brass casting, causing a condition known as ' ' l)rass-f ounder 's ague " . . . . . . 1058 150. A very dusty trade — drum with nails which combs out the small pieces of broom corn ......... 1067 151. Faulty posture 1082 152. The Heusinger desk 1083 153. Boston school desk and chair ........ 1084 154. Bevice for determining carbolic coefficients ..... 1113 155. Section through Arnold steam sterilizer . . . . . . 1123 156. Section through autoclave ........ 1124 157. Bramhall-Deane steam sterilizer ....... 1124 158. Cross section through steam disinfecting chamber .... 1125 159. Longitudinal section through steam disinfecting chamber . . . 1127 160. Kinyoun-Francis disinfecting chamber . . . . . . . 1128 161. Automatic thermometer ......... 1129 162. Plan showing the method of installing the double-ended steam cham- bers at a national quarantine station ..... 1130 163. Chart showing an application of steam under pressure . . . 1131 164. Flaring top tin bucket for generating formaldehyd by the permanganate method 1136 165. The pot method of burning sulphur ...... 1140 166. Large stack burner for sulphur, with 15 of the 18 pans removed to show construction ......... 1141 167. Liquefied sulphur dioxid in tin can ...... 1141 168. Section through double sulphur furnace ...... 1143 169. Camp of a regiment of infantry . . . . . . . 1196 170. The normal foot 1202 171. Shape of United States military shoe 1202 172. A rock pile crematory ......... 1208 PREVENTIVE MEDICINE SECTION I PREVENTION OF THE COMMUNICABLE DISEASES CHAPTEE I DISEASES HAVING SPECIFIC OE SPECIAL PEOPHTLACTIC MEASUEES SMALLPOX AND VACCINATION The prevention of smallpox depends primarily upon vaccination, sec- ondarily upon isolation and disinfection. Vaccination was the first specific prophylactic measure given to man; it produces an active im- munity to smallpox (variola). On account of its importance and great practical value this subject will be considered in some detail, for much of the antivaccination sentiment is due to ignorance or misconstruction of the facts. Historical Note. — The credit of giving vaccination to the world is due to Jenner, who proved through carefully planned experiments that cowpox protects against smallpox. This fact had been familiar to the farmers and folk of England as a vague tradition for a long time. A young girl who sought medical advice of Jenner, when a student at Sudbury, said, "I cannot take smallpox because I have had cowpox" ; this remark made a strong impression upon the young medical student. Benjamin Jesty, a Dorchestershire farmer, in 1774 successfully vac- cinated his wife and -two sons. Plett, in Holstein, in 1791 also success- fully vaccinated three children. It was Jenner, however, who through logical and scientific methods proved that a person who has had the mild disease, cowpox, enjoys protection against the serious and often fatal disease, smallpox. Waterhouse and others soon repeated and cor- roborated Jenner's experiments and helped to establish the soundness of his conclusions. Jenner made his crucial experiments in 1796, when he transferred the vaccine matter from the hand of a dairy maid (Sarah Nelms) to 3 1 2 DISEASES HAVING SPECIAL PROPHYLAXIS the arm of James Phipps, a boy about 8 years old. Sarah Nelms scratched her hand with a thorn and "was infected with the cowpox from her master's cows, in May, 179G." Jenner transferred the vaccine virus from the eruption upon the hand of Sarah ISTelms to the arm of James Phipps on May 14, 1796. A typical take followed. "In order to ascertain whether the boy, after feeling so slight an affection of the system from the cowpox virus, was secure from the contagion of the smallpox, he was inoculated the first of July following with variolous matter, immediately taken from a pustule. Several slight punctures and incisions were made on both arms, and the matter was carefully in- serted, but no disease followed. The same appearances were observable on the arm as we commonly see when a patient has had variolous mat- ter applied, after having either the cowpox or the smallpox. Several months afterward he was again inoculated with variolous matter, but no sensible effect was produced on the constitution." In addition to such direct experimental proof, Jenner inoculated smallpox matter into ten persons who had at some previous time con- tracted cowpox. Date of Inoculation with Smallpox 1. 1778 2. 1791 3. 1792 4.) . [1795 D.C 6. 7. Il797 9. 10. After 1782 Not stated Name Mrs. H. Mary Barge Sarah Portlock S Joseph Merret William Smith TElizabeth Wynne J Sarah Wynne [William Rodway Simon Nichols John Phillips Ascertained to have had Cowpox When very young 31 years previously 27 years previously 25 years previously 1, 5, 15 years previously 10 months previously 9 months previously 38 years previously Some years previously 53 years previously In justification of such human experimentation it should be re- membered that at that time the inoculation of smallpox matter into healthy individuals was an acknowledged method of preventing that disease. Jenner himself was inoculated when a boy. The question of "inoculation" (with smallpox) as contrasted with "vaccination" (with cowpox) will be discussed presently. With such proof as this Jenner put a popular belief upon a scien- tific basis. He demonstrated that cowpox is a local and trivial disease in man, that it may be readily transferred from man to man, and that it protects against smallpox. The chain of evidence was complete, but he first proved his thesis to his own satisfaction before he gave it to the world. He said himself: "I placed it on a rock where I knew it would be immovable before I invited the public to take a look at it." SMALLPOX AND VACCINATION 3 Jenner presented the results of his observations to the Eoyal Society, of which he was a Fellow, but the paper was refused. He then published it in 1798 as a book, modestly entitled, "An Inquiry Into the Causes and Effects of the Variolae Vaccinae, a Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cowpox." Every student of preventive medicine should read this brief "inquiry" in the original. It may be taken as a model of careful observation and logical presentation, showing great self-restraint and moderation of an observant, Imaginative, and judicial mind. Dr, Benjamin Waterhouse, the first professor of Theory and Prac- tice of Physic in the Harvard Medical School, early became convinced of the value of Jenner's demonstration and obtained some vaccine virus on threads from abroad. On July 8, 1800, he vaccinated his son, Daniel Oliver Waterhouse, then five years old. This was the first person vac- cinated in America, so far as existing records show. After successful vaccination his two sons and other members of his household were inocu- lated at the Smallpox Hospital by Dr. Zabdiel Boylston, with negative results. In Boston on August 16, 1802, nineteen boys were vaccinated with the cowpox. On November 9th twelve of them were inoculated with smallpox; nothing followed. A control experiment was made by inocu- lating two un vaccinated boys with the same smallpox virus; both took the disease. The nineteen children of August 16th were again unsuc- cessfully inoculated with fresh virus from these two boys. This is one of the most crucial experiments in the history of vaccination, and fully justified the conclusion of the Board of Health — "cowpox is a complete security against the smallpox." Thomas Jefferson helped materially to spread the new doctrine in this country, and, in 1806, in writing to Jenner, said : "Future nations will know by history only that the loathsome smallpox has existed and by you has been extirpated." This prophecy has by no means been ful- filled — ^though eminently possible. VACCINATION Vaccination may be defined as the transference of the virus from the skin eruption of an animal having vaccinia or cowpox into the skin of another animal. Vaccination, then, consists in introducing the active principle of cowpox into the skin of a susceptible animal. For over one hundred years vaccination (from vacca — a cow) was a specific term limited to the introduction of the virus of cowpox into the skin, in order to induce vaccinia and prevent variola. In recent years, however, the term has been used in a generic sense to include the introduction of 4 DISEASES HAVING SPECIAL PEOPHYLAXIS many different substances in many different ways and for many different purposes. Thus we speak of attenuated or killed bacterial cultures as bacterial vaccines; and the subcutaneous inoculation of organic sub- stances of diverse origin and nature is often spoken of as vaccination. We hear of typhoid vaccines, anthrax vaccines, staphylococcus vaccines, and we read in the literature of animals "vaccinated" with extracts of cancer and other organic substances. For distinction between a vaccine and a virus, see page 396, VACCINE VIRUS Vaccine virus is the specific principle in the matter obtained from the skin eruption of animals having a disease known as "vaccinia" or "cowpox." Vaccine virus is obtained from calves, man, the buffalo, sometimes the camel, rabbits and other animals. Cowpox, or vaccinia, is an acute specific disease to which many animals are susceptible, namely, man, cattle, camels, rabbits, monkeys, guinea-pigs, rats, etc. The disease runs practically the same clinical course in all susceptible species. The eruption is always ^ local and confined to the site of the vaccinated area; the constitutional symptoms are always benign and usually slight. Vaccinia or cowpox is a benign disease ; when uncomplicated, it has never been known to cause death or leave any unpleasant sequelae. After an incubation period of from three to four days the local eruption begins as a papule which soon develops into a vesicle, and later into an umbilicated pustule. Surrounding the vesicle is a red- dened, inflamed, and tender areola. The neighboring lymph glands are swollen and tender, and there may be slight fever lasting several days. The pustule dries, leaving a crust or scab, which comes away, dis- closing a typical f oveated or pitted scar. Human and Bovine Vaccine Virus. — Vaccine virus is usually obtained from (1) bovine or (2) human sources. Human virus is now seldom used, for the reason that the supply would not be sufficient. Upon the appearance of a smallpox outbreak it is sometimes necessary to have enough virus to vaccinate one hundred thousand or more people. Such large quantities evidently could not be obtained from man at any desired time. Another objection to the use of human virus is the possibility, although small, of transmitting syphilis, and perhaps other diseases. When human seed is used the virus may be transferred directly from arm to arm ; or the virus may be preserved dry in the scab ; or the con- tents of the vesicle may be kept in either a dried or moist state, as de- scribed below for bovine virus. Arm-to-arm vaccination is still practiced in several parts of the world, particularly in Mexico, where it is claimed * Rare exceptions to this statement will be noted later. SMALLPOX A^B VACCINATIOIsT 5 that it has the advantage of producing a better take ; that the results are surer in that there are fewer unsuccessful vaccinations; and, finally, it is stated that the human virus affords a better immunity, but as to this there is no proof and some doubt. Bovine virus has been used more or less since the time of Jenner, but especially since Copeman showed in 1891 how to purify it with glycerin. It has the great advantage of being readily obtained in any amount and when desired. It may be purified, and it further totally eliminates the danger of conveying syphilis and other diseases peculiar to man. Fornis of Vaccine Virus. — Vaccine virus may be used in one of three forms: (1) fresh, (2) dry, (3) glycerinated. The fresh virus may be taken from the eruption of the calf or man and transferred directly. Thus the Institut Vaccinale at Paris still prefers to use the fresh virus. The vesicle is squeezed at its base be- tween the blades of forceps, and some of the content is transferred directly from the calf to the skin of the arm by means of a thumb lancet or any similar instrument. The vaccinal matter may be dried, and the virus remains potent in this state a very long time, especially if kept cold and protected from light. The virus may be dried upon a splinter of ivory or other sub- stance. Formerly physicians preserved the dried crust from a typical take. When needed, small portions of this crust were ground, moistened, and inserted into the skin. Glycerinated virus consists of vaccine pulp treated with 50 per cent, pure glycerin. This purifies it and hence is preferable. Before taking up the question of glycerination, we must understand the difference be- tween vaccine lymph and vaccine pulp. Vaccine Pulp and Vaccine Lymph. — A distinction is drawn between the pulp and the lymph. The pulp consists of the entire vesicle with its contents, which is scraped from the skin, and is composed of epi- thelium, leukocytes, bacteria, products of inflammatory reaction, the fluid content of the vesicle, debris, etc. The lymph is the serous fluid contained in the vesicle or which often exudes from the broken vesicle. When the eruption is produced on the skin of a calf in a large con- fluent area, the surface of the eruption is scraped away and the exuding lymph is placed upon points by dipping or brushing. Most of the active principle of vaccine virus is contained in the epi- thelial cells, and this portion is largely lost when only the lymph is used. The lymph taken after the 8th day is apt to produce unduly inflamed takes, or to produce abortive vesicles, called spurious takes by the first vaccinators. The pulp, which includes the lymph, therefore contains the virus in greater concentration, and is almost exclusively used in this country at the present time. 6 DISEASES HAVING SPECIAL PROPHYLAXIS Dry Points Versus Glycerinated Vaccine Virus. — T}ie old-fashioned dry points were prepared by dipping.. splinters of ivory into the vaccine lymph. Later the lymph was collected upon a brush and thus trans- ferred to the tip of the ivory point. Bone or glass may be substituted for ivory. Bone is undesirable because it is difficult to sterilize. The only advantage of the dry point is its convenience in vaccinating. Its dis- advantage is that the virus dried upon such points cannot be purified as is the case with glycerinated pulp. Further, the points are used as scarifiers and the method of scarification favors irritation and infection of the wound. The dry points practically always contain more bacteria than the glycerinated virus. For these reasons dry points are no longer permitted in interstate traffic in accordance with the federal regulations. The old-fashioned dry points must not be confused with certain points containing a drop of glycerinated lymph now placed on the market by manufacturers. There is no special objection to these, except that it encourages vaccination by the method of scarification. Some manufac- turers imitate the old-fashioned dry point by removing most of the glycerin from the ripened pulp by pressing it between blotting papers. The remaining pulp is then attached to the points with sterile dextrose, blood serum, or some other gummy substance. The Process of Ripening. — When the vaccine virus is fresh it is said to be "green." Glycerin is added to the green pulp, and after it has acted a certain period of time the virus is said to be "ripe." The use of glycerin for this purpose was introduced by Moncton Copeman ^ in 1891 for the purpose of preserving and purifying the virus. The glycerin acts as a ditferential germicide, that is, it preserves ^ the active prin- ciple in the vaccine virus, but destroys the frail non-spore-bearing bac- teria. In time the virus itself succumbs. Vaccine virus must, there- fore, not be used while green nor when too old. Manufacturers usually date their products as "not reliable after" 4 to 6 weeks in the summer time, and 3 months during the cold season. Fifty per cent, glycerin of the best quality is used. I have shown that no growth of bacteria, yeasts, or molds takes place in 60 per cent, glycerin. Two to four parts of 50 per cent, glycerin are added to 1 part of the pulp by weight. The mixture is then thoroughly ground with a mortar and pestle by hand, or between glass rollers in a special mill driven by machinery. The pulp should be thoroughly broken up and a uniform suspension obtained. The amount of glycerin added depends upon the consistency and character of the pulp. The only objection to adding more glycerin would be the greater dilution of the virus, and, therefore, a larger proportion of negative takes. A higher percentage ^Transactions of the International Congress of Hygiene, 1891. ''Glycerin also serves as a preservative for other filterable viruses, as foot- and-mouth disease, anterior poliomyelitis, rabies, etc. SMALLPOX AND VACCINATION 7 than 50 per cent, of glycerin soon renders the virus inert. The glycerin probably destroys the bacteria by virtue of its dehydrating action. The time required for the virus to ripen depends upon the temperature. Most of the non-spore-bearing bacteria perish in 30 days at 15° to 20° C. Approximately the same effect may be obtained at 37° C. in a few hours. At low temperatures the glycerin has practically no bactericidal effect. The process must always be controlled bacteriologically. Substances other than glycerin are used for the purpose of purifying vaccine virus. Carbolic acid (0.5 to 1.0 per cent.) is used with success in Japan, and to some extent in this country. Potassium cyanid, chloro- form, chlorobutanol, etc., have been tried, with less success in practice. Bacteria in Vaccine Virus. — Vaccine virus obtained from the skin always contains bacteria. However, the bacteria which contaminate vac- cine virus are, for the most part, harmless to man. They are commonly those that are found on and in the skin of the calf. The non-spore-bear- ing varieties are largely eliminated by the process of ripening. There are fewer bacteria in the typical unbroken vesicle than in the pustule or in a broken, crusty, inflamed eruption. Green virus may contain from a few thousand to over a million bacteria per cubic centimeter. The ripened, glycerinated virus contains much fewer, and these mostly harm- less saprophytes. The number of such bacteria in the ripened virus may be taken as an indication of the care and cleanliness with which the virus has been prepared. Staphylococci, streptococci, members of the hemor- rhagic septicemic group, and, in a few instances, tetanus spores and the gas bacillus have been found in vaccine virus. Noguchi^ by painstaking methods recently obtained a bacteria-free vaccine virus, which may be propagated in the testicles of bulls or rab- bits. Human beings react to the testicular strain in an entirely typical manner and this may furnish a satisfactory method for the production of a safe and strong vaccine virus. Seed Vaccine. — The seed virus may be obtained (1) from cowpox, (2) from smallpox, (3) by retro vaccination. "Spontaneous^' or casual cowpox occasionally occurs ; that is to say, the disease appears to arise spontaneously because its origin cannot be traced. Casual cowpox comes either from another case of cowpox or from a case of smallpox. Cattle are not subject to smallpox, but, when small- pox virus is introduced into the skin of a calf, it produces cowpox. When smallpox is thus converted into cowpox, it remains fixed as such, and never reverts to smallpox.^ In several instances in England, Ger- many, and this country the seed virus has been obtained by starting cowpox through the inoculation of smallpox virus. Such virus should ''Jour, of Exp. Med., June 1, 1915, XXI, 6, p. 339. ^ It is highly significant that casual cowpox was formerly much more com- mon when smallpox was much more prevalent. 8 DISEASES HAVING SPECIAL PEOPHYLAXIS not be used until several transfers from calf to calf have been made, for the reason that some of the smallpox virus may be carried over unaltered, during the first few transfers. Retrovaccination consists in carrying the vaccine virus back from child to calf; better still, the virus may be passed from man through rabbit, monkey, or other susceptible animal, and then again to the calf. Changing the species helps to maintain the activity of the vaccine virus for an indefinite time; furthermore, the change leaves behind cer- tain associated bacteria which may gather increased virulence by suc- cessive passage from animal to animal of the same species. Propagation. — In the propagation of bovine virus young calves are preferred, because they are more manageable, the skin is more tender, and the eruption is therefore more abundant and typical. With young animals a milk diet may be used, which simplifies the problem of dust contamination from dry feed. If hay or fodder is used, it must first be autoclaved. Either heifers or bull calves are suitable, although the former are preferred. The animals are held in quarantine for seven days, under observa- tion, to determine the absence of infections such as tuberculosis, glan- ders, foot-and-mouth disease, tetanus, fever, diarrhea or skin eruptions of any kind. Before vaccinating the calf it is carefully cleaned, and the site of the inoculation is shaved and prepared surgically, but without the use of germicidal solutions. Germicides are not suitable for the reason that they are apt to destroy the vaccine virus. Cleanliness and asepsis are the watchwords. The area selected is usually the abdominal wall be- tween the tip of the sternum and the groin, sometimes including the inner side of the thigh. The usual method is to make long, superficial incisions in the skin about one centimeter apart, and the seed virus is gently rubbed into these incisions. The calves must then be kept rigidly isolated in a special room, moderately lighted, free from dust, and screened to keep out insects. The temperature of the animal is taken several times daily, and the eruption at each stage of the disease is closely watched and recorded. The virus is usually taken from the animal on the fifth day. It is an advantage to take the virus as early as practicable, in order to avoid con- taminating infections which may occur when the vesicles suppurate. Vaccine virus taken after the eighth day is unreliable. Jenner's golden rule was to take the virus before the areola appeared. Only typical and entirely characteristic vesicles should be removed. Before the virus is removed, the animal is chloroformed to avoid pain, and an autopsy is done as soon after the virus is removed as practicable. If the autopsy shows any lesions indicating infections other than vaccinia, the virus is dis- carded. SMALLPOX AND VACCINATION 9 It is not wise in propagating vaccine virus to vaccinate too large an area. This favors infections by lowering resistance ; furthermore, less typical eruptions are obtained than when the area vaccinated is moderate in extent. A yield of from twenty to twenty-five grams of pulp from one calf should satisfy the propagator. Before the virus is taken the animal is placed upon a special table, the site of the vaccination exposed and given a very thorough washing and prolonged scrubbing with soap, and an abundant flushing with sterile water. The pulp is obtained by scraping the vesicles with a sharp spoon curet. Glycerin (50 per cent.) in proper proportion is added at once to the pulp, and this is ground to a state of fine and uniform subdivision in a Csokar lymph mill, or simply by hand with a mortar and pestle. This glycerinated pulp is then allowed to ripen, and when ripe it is hermeti- cally sealed in capillary tubes, or placed in small vials for the market. METHODS OF VACCINATION Vaccination consists in transferring the virus of cowpox from one animal to the skin of another animal. The operation of vaccination con- sists of introducing vaccine virus into the skin. Under no circvimstances must the vaccine virus be placed under the skin or subcutaneously. The operation may be compared to the transfer of a culture in a bacteriologic laboratory. Precisely similar precautions to prevent contamination must be used in both cases. Vaccination must be regarded as a surgical opera- tion. No person unfamiliar with surgical cleanliness should be per- mitted to perform this "little" operation. The vaccine virus may be introduced in one of three ways: (1) by puncture, (2) by incision, or (3) by scarification. Jenner used punctures or short incisions. Later blisters were raised upon the skin and the virus placed upon the abraded surface. The incisions were then increased in number, and finally cross scratchings or scarifications were made. Puncture. — The simplest method is puncture into the skin with a needle moistened with the vaccine virus; this gives little chance of con- tamination and the eruption is typical. The disadvantage is that the virus now used is diluted with glycerin, and therefore somewhat atten- uated, so that a few simple punctures are less apt to take. Incision. — The method advised and recommended is that of incision. Incision is the only method of vaccination permitted by the laws of Germany, and recommended by the Local Government Board of Eng- land. Incision, if not too deep, consists really of a series of punctures, and serves the same purpose. Incisions may be made with the point of a scalpel. I prefer to use a needle. The incision or scratch should not 10 msEASEs i-iAvma special prophylaxis be deep enough to draw blood, but a few drops do no harm. It is rather difficult to control the depth of the incision with a scalpel, especially if it is sharp. Scratching with a needle is much more easily controlled. The incisions should be about one inch long and about an inch apart. The vaccine virus is first placed upon the skin in two small droplets about an inch apart. The point of the needle is now moistened in the droplet and as the scratch is made the needle carries the virus along with it into the little wound. With the flat of the needle the virus should be gently rubbed (not ground) into the scratch. It is important not to cause any unnecessary irritation so as to avoid attracting infections. Scarification. — Scarification or cross-scratching is prohibited in Ger- many by ministerial decree of March 31, 1897, which was incorporated into the revised rules of the Bundesrath, July 28, 1898. The objec- tion to scarification is that this method produces an abraded surface which is soon covered by a dry, hard crust of serum and blood, through ■which the eruption cannot pierce. The vesicles form a ring around the scarified area, leaving a central irritated wound, inviting infection. It is believed that most of the cases of tetanus complicating vaccination oc- curred in cases in which scarification was used. In this method favor- able anaerobic conditions are produced under the crust or scab which forms over the abraded surface. The Point of Election. — The outer surface of the left arm at about the insertion of the deltoid is the most convenient for the operator and the patient. This is the original site selected by Jenner, and is less liable to severe glandular complications than other points. Elachs recommends the side of the chest at about the level of the sixth rib, in the axilla. Here the scar is not visible; there is little mo- tion, and it is easily bandaged, but this site is open to the disadvantage of greater heat and moisture and there is, therefore, greater danger of complications. The leg is sometimes selected to avoid disfigurement. The vaccina- tion scar should not be regarded as a deformity. To the sanitarian a typical vaccine scar is a sanitary dimple. The leg is more exposed than the arm to traumatism, and, therefore, to complications. Dock refuses to vaccinate on the leg unless the patient will stay in bed until the vesicle heals. With babies in diapers and with young children it is exceedingly difficult to keep these parts clean. If the leg is selected, the vaccination should be done on the calf below the head of the fibula, and not on the outer surface of the thigh. Number of Incisions. — This has an important bearing upon the probability of the take, as well as the protection. It is not wise to de- pend upon one. There is a definite relation between the number of vesicles and the degree and length of the immunity (see page 17). The German regulations of 1899 require at least four incisions, each one cen- SMALLPOX AND VACCINATION 11 timeter long and two centimeters apart. The Local Government Board of England directs that four vesicles should be produced, and that the total area of the vesicle formation shall not be less than one-half a square inch. My own practice follows that of Dock, who makes not less than two incisions about an inch long and an inch apart; but in case of ex- posure to smallpox three or four such incisions are advisable. The Operation. — The skin at the site of the operation must be sur- gically clean, but need not necessarily be treated with antiseptics. If such are used, they must be carefully washed away in order not to destroy the activity of the virus. A thorough preliminary scrubbing Tig. 1. — ^Vaccination Scars Prodttced by Method of Scarification. with soap and water is necessary for a dirty skin. Washing with warm water followed by alcohol is usually enough. The alcohol should be per- mitted to evaporate before the vaccine is applied and the incision is made. In general, the less the skin is irritated the less the danger of complica- tions. Needles are particularly handy, as they may be flamed just before the operation, and are convenient in saving time when many people are to be vaccinated. The vaccine virus is gently rubbed into the incision, not ground in, and then allowed to dry. No dressing is necessary at the beginning, but several layers of dry sterile gauze held in place by adhe- sive plaster do no harm, and serve as a protection. Pads, plasters, and shields of any sort are unwise, because by retaining heat and moisture they cause a softening and breaking down; in other words, they act like a poultice. Bathing need not be omitted, nor any of the ordinary occu- pations, but unnecessary use of the arm must be guarded against, as this increases the congestion, inflammation, and the chances of infection. INDICES OF A SUCCESSFUL VACCINATION The take must be typical and the clinical course characteristic, other- wise we have no assurance that the individual is protected against small- pox. The best indices of a successful take are: (1) the course of the eruption, (2) the general symptoms, and (3) the scar. 12 DISEASES HAVING SPECIAL PKOPHYLAXTS The importance of knowing the skin lesions of vaccinia were in- sisted upon by Jenner. Every vesicle, scab, ulcer, or irritated wound is not vaccinia. No confidence should be placed in doubtful or atypical takes. The characteristic features of vaccination are singularly alike. The clinical course of a primary vaccination is as follows : Course of the Eruption. — The primary wound soon heals. Appar- ently nothing occurs for 3 to 4 days, which is the period of incubation. PUNCTURE PUSTULE 9THDAY PAPULE 4TW DAY PES I GC AT I O N 12TH DAY VESICLE J"'" DAY CRUST I8TM0AY UMBILlCATION7T«DAY FOV EAT ED SCAR. Fig. 2. — The Cotjkse of the Ebuption (Diagrammatic). Then one or more small papules appear upon the skin where the vac- cine virus was introduced. The papule is small, round, fiat, bright red, hard, but superficial. About the fifth day the summit of the papule becomes vesicular. The vesicle is at first clear and pearl-like. Umbilica- tion soon develops as the vesicle enlarges. A deep, red, and swollen areola surrounds the vesicle and grows wider as the lesion advances. This gives the picture of the "pearl upon the rose leaf" which consti- tutes the true jennerian vesicle. By the seventh day the vesicle is full size, round or oval, fiat on top, umbilicated, and contents clear. It is SMALLPOX AND VACCINATION" 13 multilocular ; if pricked with a pin or accidentally opened only that portion of the lymph contained in the compartment opened will exude. By the eighth day it turns yellowish, the middle is fuller, following which the so-called second umbilication develops. Meanwhile the areola deepens, widens, and may be swollen. The skin feels hot, is painful, and the axillary glands become enlarged and tender. About the ninth day the areola begins to fade and the swelling subsides. By the eleventh or twelfth day the pustule rapidly dries, leaving a brown, wrinkled scab, which finally drops off. It should never be removed, as it forms the best bandage. The scar is at first red, finally turns white, with the pits or fovea- tions so characteristic of true cowpox. General Symptoms. — The general symptoms vary. There are malaise, loss of appetite, sometimes nausea and vomiting, headache, pain in the muscles of the back, and other indications of a mild febrile reaction. The temperature may go to 38° or 38.5° C. as the vesicle ripens. The febrile reaction bears no special relation to the size and number of the vesicles or to the areola. The regional lymph nodes become enlarged and tender about the time the pustule forms. The nitrogen elimination increases about the tenth day for a short time. The blood changes re- semble those of smallpox, an early leukopenia and secondary leukocytosis. Secondary vaccinations often run an accelerated, milder, or modified course with shortened periods of incubation (see revaccination) , THE IMMUNITY The immunity appears about the eighth day of the vaccination. Layet puts the point of safety at the ninth day, Burckhard at the elev- enth. These data are based upon the early work with variolation, when persons were inoculated with smallpox at various periods following vac- cination. Sacco got only a local eruption by inoculating smallpox on the eighth to the eleventh days, and none after that. Vaccination protects not only against smallpox, but also against vac- cinia. Curioiisly enough, the degree and length of immunity appear to be greater against smallpox than against itself. It is irrational to at- tempt to fix a definite time for the duration of the immunity. This varies as in. other infectious processes. It is known through experiment and experience that the immunity gradually wears off. Definite protec- tion on the average lasts about seven years. The degree of protection is usually absolute for some years, and then gradually fades. In this, as in other diseases, immunity is a relative term. Smallpox itself does not always protect against smallpox. Some people have two and even three attacks of smallpox.^ Such cases, however, are exceptional, and ^ Jenner mentions "the lady of Mr. Gwinnett, who has had the smallpox five times." — Baron's "Life of Jenner," Vol. II, p. 265. Eighth Day Ninth Day Fig. 3. — Vaccinia. Course of the Eruption from the Fourth to the Ninth Day. 14 Fourteenth Day Scar — Sixth Week Fig, 4. — Vaccinia. Course of the Eruption from the Tenth Dat> 15 16 DISEASES HAVING SPECIAL PROPHYLAXIS it is also exceptional to have smallpox occur in an individual who has been properly vaccinated. s In Liverpool Sbcnvlns the rcloHvc weverlty c»f the . ThU Dla^nun ■• tnMmi PIRSONB VAOOINATED IN INFANCY. MALLPOX durlne: ton yoars (I902-1911), dlt^c-Hsc OB It arrccia vacclnotcd and unvacclnaud pervon*. on «h* rMor4a of Ilea c»ms of ftmUlpox. ,oox ,™.. UN-VAOOINATED PERSONS. Fig. 5. Note : — 1. No cases of Smallpox under 2 years of age. 2. Great majority of persons attacked have the disease in mild form. 3. Gradual loss of vaccination immunity as age advances. 4. No deaths occur until later life. Note : — 1. Many cases occur under 2 years, and comparatively large proportion of these children die. 2. No influence to control the fatality of the disease, except the recuperative pow- er of youth, as seen from 10-30 yrs. 3. Deaths very numerous in children under 10 years, and persons over 40 years. Careful statistics collected in Japan since 1879 show quite definitely the gradual diminution of the immunity, beginning with the second year after vaccination. Kitasato's table/ based on 951 cases, is as follows: SUCCESSFUL REVACCINATION AFTER: 1 year 13.6 per cent. 2 years 32.9 " " 3 years 46.6 " " 4 years 57.3 " " 5 years 51.1 " " 6 years 63.8 " *< VpMr. A. M. A., March 2.5, 1911, p. 889, SMALLPOX AND VACCINATION 17 Weil, in 1899, reported 72.5 per cent, of successful revaccinations after seven years, 80 per cent, after eight years, 85 per cent, after nine years, and 88.6 per cent, after ten years. It is commonly asserted that, if a revaccination takes, the subject was therefore susceptible to smallpox. While this is usually true, it does not necessarily follow. It is a still greater fallacy to state that, if a vaccina- tion fails, the subject is therefore immune. This view may result in real harm. Vaccination may fail for many reasons — the operation may not have been properly done, or the virus may have been inert. Sometimes persons are unsuccessfully vaccinated three, four, or more times before a typical take is obtained.^ There appears to be a definite relation between the immunity con- ferred and the number of vaccination scars. There is also some evi- dence that the protection is directly proportional to the area of the local eruption. This question has not been carefully studied since the data contained in the final Eeport of the Koyal Commission on Vaccination, which is summarized in the following table : MORTALITY OF POSTVACCINAL SMALLPOX IN RELATION TO THE NUMBER OF SCARS Number of Scars 3,094 cases* (1836-51) 10,661 cases* (1852-67) 6,839 cases t None 21.7% 39.4% 1 7.6 13.8 6.2% 2 4.3 7.7 5.8 3 1.8 3.0 3.7 4 0.7 0.9 2.2 * Final Report of the Royal Commission on Vaccination, 1896, paragraph 291. Dr. Thome, from data collected by Mr. Marson. t Same Report, paragraph 293. Summary of cases apart from those of Mr. Marson. One point needs emphasis: The degree and duration of the im- munity are directly proportional to the typical nature of the take. No reliance should be placed upon atypical reactions. The nature of the changes in the body which produce the immunity are not understood. In this sense vaccination is still an empiric pro- cedure. We now know of many analogous instances, however, where an active acquired immunity is induced by means of an attenuated virus. The immunity produced by vaccine virus does not depend upon an anti- ^ One of my cases gave a history of having been unsuccessfully vaccinated five tiwiQS- The six^h ^.ttempt produced a typical primary take with 21 vegiclea. 18 DISEASES HAVING SPECIAL PEOPHYLAXIS toxin. The blood, however, contains specific antibodies, shown by the fact that the activity of vaccine vims is destroyed when mixed with equal parts of blood serum from a calf two weeks after successful vacci- nation. REVACCINATION The fact that the immunity wears off after a number of years makes it necessary to practice revaccination in order to afford a continuous protection. There is some difference of opinion as to just when it is best to vaccinate the second time. Ten years is too long a period, prob- ably, to depend upon in individual cases. One year — advised by some — is shorter than necessary in most cases. The five-year interval of Japan is good in many respects, but probably not better than revaccination in the twelfth year obligatory in Germany. The best time to vaccinate is in the first year before the second sum- mer, again at from ten to thirteen years. After this it is usually un- necessary to vaccinate again, unless there is particular danger of expo- sure to smallpox. All persons exposed directly or indirectly to smallpox should at once be vaccinated — unless they have had the disease or have recently been successfully vaccinated. There are no contraindications to vaccinating babies immediately after birth. The clinical picture of secondary vaccinations may be quite different from the typical take following a primary vaccination. These altered reactions were known in the time of Jenner, but were lost sight of until recently rediscovered, and their significance realized from studies in anaphylaxis. Eevaccinations may be divided into three groups: (1) they may run an unaltered course resembling primary takes in all respects, showing that immunity to cowpox has disappeared; (2) they may run a somewhat more rapid course in which the period of incubation is shortened and in which the height of the pustular stage occurs about the sixth day (this is known as the accelerated reaction) ; or (3) they may run a very much shortened, milder, and rapid course. The eruption may be pply a small papule which does not develop into a vesicle and soon dis- appears; the period of incubation may be less than 24 hours. This is knowp as the imnaediate reaction and resembles a cutaneous tuberculin reaction in many respects. These altered reactions have been studied .especially by von Pirquet and are shown graphically in Fig. 6. The immediate reaction may be pu.t to practical use in order to dis- tinguish smallpox from chickenpox. Thus, Tieche has shown that small- pox virus introduced into the skin of a person immunized by vaccination will show the typical immediate reaction; whereas the virus of chicken- pox is invariably negative. This test can be freed of all possible danger OJ O CO ^ vS LO ^ H O « IH H o-« ^; « « S i « S £ I— I . 'd JH H o y-o cO c\J ® ® ® 2 2; 12 ^ Ph 2 2 , E^ P s fe ■< "^ 2 t O 12 g ^.1 »l o cse: a ui W 19 O 20 DISEASES HAVING SPECIAL PROPHYLAXIS by heating the virus to 60° C. for 30 minutes, which does not seem to affect the reaction, CLAIMS FOR VACCINATION 1. "Duly and efficiently performed it will protect the constitution from subsequent attacks of smallpox as much as that disease itself will." ^ 2. It protects the individual against smallpox for a period which has not been determined mathematically for the individual, but which averages about seven years. 3. The protection may be renewed by a second vaccination. 4. Persons successfully vaccinated on two occasions are usually immune against smallpox for life. 5. Vaccination and revaccination systematically and generally car- ried out confer complete protection to a community or a nation. In other words, while the individual protection is not always perfect, the communal protection is absolute. 6. A person vaccinated once and at a later time contracting small- pox as a rule has the disease in a less serious form than unvaccinated persons (varioloid).^ The degree of favorable modification of smallpox is in inverse proportion to the period of time elapsing between the vac- cination and the attack of smallpox. 7. The beneficial effects of vaccination are most pronounced in those in whom the vaccine affection has run its most typical and perfect course. VACCINATION OF EXPOSED PERSONS The question frequently arises whether persons exposed to smallpox should be vaccinated. The effect of vaccination during the period of incubation of smallpox is very interesting, and may be summed up as follows : 1. Vaccination just before or during the primary fever of smallpox does not influence the disease. 2. If the vaccination is done during the last stage of the period of incubation of smallpox, the two infections run their course side by side without influencing each other. 3. If it is done about the sixth or eighth day of the period of in- * "I never expected that it would do more, and it will not, I believe, do less." — Jenner. Baron's Life, Vol. II, p. 135. ^The term varioloid was introduced by Thompson in 1820 to describe the mild and modified form of smallpox occurring after vaccination. The eruption in varioloid disappears more rapidly than in variola. Yolfert, Dornbleuth, and Harden showed that one vaccination was not always sufficient protection against smallpox for a lifetime, that revaccination was neces- sary and that the clinical manifestations of this vaccination are as different from, those of the first vaccination as varioloid is from variola. SMALLPOX AND VACCINATION 21 cubation the vaccination takes and may modify the severity of the smallpox. 4. Vaccination done at the beginning of the incubation period, in time to have the vaccine eruption reach maturity before the smallpox begins, will prevent or abort the disease. This is shown in the follow- ing diagram : THE EFFECT OF VACCINATION DURING THE PERIOD OF INCUBATION OF SMALLPOX Toward the During the Early in the Middle of the end of the Primary On the Incubation Incubation Incubation Fever, or First Period Period Period Preemption Day 2nd to 6th days 6th to 8th days 9th to 14th days Stage - Variola Prevents Smallpox is Varioloid or Smallpox not Smallpox not smallpox aborted mild case influenced influenced 1 1 MM! 2 3 4 5 6 \ I 1 1 1 1 1 1 9 10 11 12 13 14 III 1 2 3 1 Period of M M 1 Incubation of f mallpox — ^in Days 1 1 1 1 1 1 Primary Fever Eruption The vaccina- The vaccina- The vaccina- The vaccination takes The vaccination tion takes. tion takes. tion takes 2 or 4 days be- fore primary fever. and both affections run side by side. does not take (?) To produce the best results the vac- "Vaccinia cination should precede this period, so as to reach maturity before the onset of the primary fever. The vaccine vesicle reaches maturity about the 8th day. _ As we can never be quite sure Just what stage in the period of in- cubation a given case may be in, it is always advisable to vaccinate exposed persons. Furthermore, little harm will be done if it is too late and the vaccine eruption is added to the smallpox. Indeed, Hanna^ presents claims to the effect that there is evidence in mitigating the severity of smallpox when vaccination is performed at any time after infection up to the day of onset and even afterward. DANGERS AND COMPLICATIONS The alleged danger from vaccination has been greatly magnified by the antivaccinationists. However, vaccination is not always a harmless procedure ; it must be looked upon as the production of an acute infec- tious disease, and, although the disease is always mild and benign, it must not be treated as trifling. The chief danger lies in the fact that 'Public Health, July, 1910, XXIII, No. 10, p. 351. 23 DISEASES HAVING SPECIAL PKOPHYLAXIS we have produced an open wound, wliicli is subject to the complications of any wound. Even a pin prick or a razor scratch may result in death. While the aggregate number of deaths resulting from the complications of vaccination may be considerable, the individual risk is so small as to be disregarded, especially when proper precautions are taken. Many of the infections after vaccination occur in those in whom the regard for cleanliness is slight, and who neglect the care of the wound. In recent years, owing to the improved quality of the vaccine virus and the introduction of aseptic methods, a bad sore arm is a rare occurrence, and serious complications still rarer. In any case, the danger connected with vaccination is infinitesimal when compared tuith the benefit con- ferred. The important complications are : Auto Vaccination. — This is usually due to scratching the virus with the finger into the nose, the mouth, the mucous membranes, or any part of the skin. When carried into the eye it may cause blindness. Physi- cians sometimes vaccinate their lips by blowing into vaccine tubes. In vaccine establishments accidental vaccination of the hand is common. Generalized Vaccination. — This is sometimes reported, but is usu- ally a mistaken diagnosis. A generalized eruption of cowpox is ex- ceedingly rare, if it ever occurs. I have seen it in the calf after intra- venous injection of a large amount of the virus, in which case there is a prolonged period of incubation. Wound infections, such as ulcers, gangrene, erysipelas, abscesses, lymphangitis, suppuration of the axillary glands, and other septic infec- tions are now exceedingly rare, and demand the usual surgical measures to prevent their occurrence. Impetigo contagiosa occasionally occurs and may be a serious com- plication of vaccination, especially the bullous impetigo or pemphigoid forms, which presumably have their origin in cattle. (Syphilis, tuberculosis, and leprosy are sometimes feared, but these are impossible with the use of bovine virus.) Tetanus. — Tetanus deserves a special word. This serious and fre- quently fatal infection sometimes complicates a vaccination wound just as it may any wound. When we consider the many millions of vaccina- tion wounds, many of which are neglected surgically, it is no surprise to learn that tetanus occasionally occurs as a postvaccinal complication. Acland is acquainted with only one instance in more than five million consecutive vaccinations in England, and even in this one there was no evidence that the tetanus was invaccinated. Over 31,000,000 doses of vaccine virus were used in the United States from 1904 to 1913 inclusive, yet only 41 authenticated cases of tetanus occurred subsequent to vac- cination.^ A study of these cases makes it clear that the infective prin- ^J. F. Anderson: United States Public Health Report, Reprint 289, July 16, 1915. SMALLPOX AND VACCINATION 23 ciple was not in the vaccine virus, but was received ten days or more after vaccination, owing to the prolonged period of incubation (20.7 days) and the high mortality (75.2 per cent.). Many of the cases fol- lowing vaccination give a history of having the vaccination scab or crust removed in some way, thus permitting infection of the wound with a reformation of the crust and the establishment of an anaerobic condi- tion. The fact that lack of care is an important factor in postvaccinal tetanus is indicated in the figures from the United States Army and Navy with a record of 585,000 vaccinations without a single case of tetanus. At the Hygienic Laboratory at Washington many hundred samples of vaccine virus representing a million and a half vaccinations have been examined without finding a tetanus spore in a single vaccine point or tube. Special tests for tetanus are required by Federal regula- tions of every lot of vaccine virus before it is placed upon the market. In the Vaccine Laboratory of the State Department of Health of Mas- sachusetts, of which I have charge, these tests are conducted in accord- ance with the recommendation of Francis,^ as follows : (a) Plant 0.25 c. c. virus into fermentation tubes of glucose bouillon and incubate immediately. Inject 0.25 c. c. of the growth at the end of 9 days subcutaneously into mice. (b) Plant 0.25 c. c. vaccine virus into fermentation tubes of glucose bouillon, heat at 60° C. for one hour and then incubate. Inject 0.25 c. c. of the growth into mice at the end of 9 days. (c) Plant 0.25 c. c. vaccine virus into fermentation tubes of ordi- nary bouillon, containing a bit of sterile tissue, and inject 0.25 c. c. of the growth at the end of 9 days into mice. (d) Inject 0.25 of the vaccine virus subcutaneously into guinea-pigs. If tetanus spores are present in the virus, one of these four methods is almost sure to detect them. The occurrence of occasional stray tetanus spores in vaccine virus was demonstrated by Carini.^ Such vaccine, however, had proved en- tirely harmless in thousands of cases. Francis also showed the vaccine virus purposely contaminated with tetanus spores will not produce tetanus in monkeys, although it will produce typical "takes." Willson ^ in 1902 claims to have found tetanus spores in the vaccine virus used in the New Jersey episode. Glycerin does not destroy the tetanus spore, and while the occa- sional danger cannot be denied it is plain that postvaccinal tetanus should usually be laid to lack of care and neglect of the vaccination wound. To prevent tetanus complications it is important to avoid scarifica- ^ Edward Francis, "Laboratory Studies on Tetanus," Hygienic Laboratory Bull., No. 95, August, 1914, U. S. Public Health Service. ^Centralbl. f. Bakt., Orig. 1904, XXXVII, p. 1147. Vo«r. A. M. A., 1902, XXXVIII, p. 1147. 24 DISEASES HAVING SPECIAL PROPHYLAXIS tion and irritation, also to avoid the use of shields and bandages which favor anaerobic conditions, to require the patient to use strict cleanliness, and to use vaccine virus that has been properly prepared and tested. Foot-and-Mouth Disease. — The infection of foot-and-mouth disease has in one instance been demonstrated as a contamination of vaccine virus.^ It is, however, impossible to convey foot-and-mouth disease to man through cutaneous inoculation. While no harm has been done to man, the contamination is undesirable, and special Federal regulations now require vaccine virus to be tested from time to time to assure its freedom from this infection. As an illustration of how seldom complications are caused by vac- cination we have the results of Germany, where in thirteen years (1885- 1893) 32,166,619 children were vaccinated. Of these 115 died within a few weeks or months after the operation, presumably of injuries in- cidental thereto. Of these at least 48 probably did not die as a direct result of the vaccination. The figures of recent years are still better, for it is now exceedingly rare for a death to be recorded as directly due to vaccination. For example, in the Philippine Islands in the past few years the United States authorities vaccinated 3,515,000 persons without a single death or any serious postvaccinal complications. THE GOVERNMENT CONTROL OF VACCINE VIRUS By the law of July 1, 1902, the vaccine virus sold in interstate traf- fic in the United States must come from a licensed manufacturer. These licenses are issued by the Secretary of the Treasury only after a careful inspection of the plant, personnel, and product by a competent government officer. The licenses are good for one year only, and are reissued only after reinspection. The government regulations require each lot of vaccine virus to be examined carefully by modern bacterio- logical methods to determine the number of bacteria, and special tests must be made to determine the absence of pathogenic microorganisms. These tests include animal inoculations, as well as cultural methods. Special tests for each lot of vaccine must be made to determine the presence or absence of streptococci, tetanus spores, the gas bacillus, and other pathogenic microorganisms, etc. The government does not guaran- tee the purity and potency of each package of vaccine virus, but through its inspections and frequent examinations of the virus on the market every confidence may now be had in the vaccine virus propagated by licensed manufacturers in this country. 1 Mohler and Rosenau, U. S. Dept. of Agriculture, B. A. I. Circular 147, June 16, 1909. SMALLPOX AND VACCINATION 35 THE UNITY OF COWPOX AND SMALLPOX The unity or duality of these two diseases has been the subject of much contention. Jenner originally considered cowpox to be a modified smallpox.^ The successful experiments in Germany, England, and this country, in which smallpox has actually been modified by passing vari- olous matter through calves has proved positively that we are dealing with two forms of one disease. Much of the vaccine virus used during the past hundred years was originally obtained from cases of casual cowpox. This virus has been shown by experience and experiments to protect against smallpox, which again makes it highly probable that we are dealing with one disease. The parasite Cytorrhyctes variolae de- scribed by Councilman, Brinckerhoff, and Tyzzer, gives a probable ex- planation of how smallpox may, under certain circumstances, become attenuated. The life cycle of this parasite interpreted by Calkins indi- cates that the mild disease, cowpox or vaccinia, is due to the asexual phase in the life cycle of the parasite which lives and multiplies in the cytoplasm of the epithelial cell; smallpox is caused by the combined asexual and sexual cycle of the same parasite, the latter phase occurring in the nucleus of the epithelial cell. When the Cytorrhyctes variolae loses its power to generate by sexual division it never again regains it ; that is, while smallpox may be modified into cowpox, cowpox has never been returned to smallpox. It seems plain that the so-called casual cowpox has its origin from smallpox through accidental inoculation in milking cows by persons hav- ing or recovering from smallpox. Once started, the propagation of the modified virus from cow to cow would be comparatively simple. COMPULSORY VACCINATION Vaccination affords a high degree of immunity to the individual, and a well-nigh perfect protection to the community. To remain unvac- cinated is selfish in that by so doing a person steals a certain measure of protection from the community on account of the barrier of vaccinated persons around them. The laws ^ and regulations relating to vaccination in the several states of the United States show marked lack of uniformity. Compulsory general vaccination can be said to exist by law only in Kentucky, Ehode * Smallpox is a disease subject to mutations. Since 1898 a mild form of smallpox has existed in this country with a death-rate of about 0.5 per cent. This mild form shows no tendency at present to increase in virulence. Chicken- pox itself may belong to the smallpox family. The two diseases are sometimes indistinguishable at the bedside. Jenner always considered cowpox and smallpox as modifications of the same "distemper," and in using vaccine lymph he was impregnating the constitution with the disease in its mildest form instead of propagating it in its virulent and contagious form. ^ Kerr, J. W., "Vaccination, and Analysis of the Laws and Regulations Re- lating Thereto in Force in the United States," Public Health Bull, 52, 26 DISEASES HAVING SPECIAL PROPHYLAXIS Island, and Porto Rico.^ Arizona, Hawaii, Maryland, New Mexico, North Dakota have laws requiring vaccination of children. Decisions in the various courts in the United States have held com- pulsory vaccination to be legal. A decision of the Supreme Court of the United States (Henning Jacobson vs. The Commonwealth of Massa- chusetts, April 1, 1905) upheld in every respect the statute, the validity of which was questioned under the Constitution : The liberty secured by the Constitution of the United States .... does not impart an absolute right in each person to be, at all times, and in all circumstances, wholly freed from restraint. Real liberty for all could not exist under the operation of a principle which recognizes the right of each individual person to use his own, whether in respect to his person or his property, regardless of the injury that may be done to others. Theoretically it would be ideal if all persons submitted to vaccination and revaccination voluntarily. But experience has shown that this is impractical, and, wherever tried, has failed. The best results have always been obtained where vaccination has been compulsory, and, in my judg- ment, this is the only present means by which smallpox may be elim- inated. The world may learn a valuable lesson from the splendid results obtained in Germany through compulsory vaccination and revaccination. In England the '^conscience clause" allows many persons to remain unvaccinated and thereby seriously diminishes the effects of the vacci- TABLE 1.— DEATHS FROM SMALLPOX IN COUNTRIES WITH COMPULSORY VACCINA- TION AND THOSE WITHOUT COMPULSORY VACCINATION Population Smallpox Deaths Average of 1886 1887 1888 1889 Deaths 1 5 9 2 4 2 14 3 5 24 17 6 12 197 168 112 200 169 275 505 1,026 23 458 182 14 17 3 54 1,213 610 865 1,212 975 16,938 25,884 ? ? 21,411 8,794 9,591 14,138 12,358 11,220 ? 16,249 18,110 13,416 15,925 ? ? 14,378 8,472 11,425 Average per Million of Popxilation Sweden* 4,746,465 Ireland* 4,808,728 Scotland* 4,013,029 Germany* 47,923,735 England* 28,247,151 Switzerland 2,922,430 Belgium 5,940,365 Russia 92,822,470 Austria 23,000,000 Italy 29,717,982 Spain 11,864,000 1 1 3 3.5 16 18.5 164 231 510 536 963 * Compulsory vaccination. ^Massachusetts, in 1809, was the first state to enact legislation relative to vaccination. SMALLPOX AND VACCINATION 27 nation laws of that land. In Minnesota the state health authorities became weary of the clamor against compulsory vaccination and assisted in having the law repealed. They said, in substance, to the people of the state: "Take your choice. Be vaccinated and protect yourself, or run the risk of contracting smallpox ; if you get it, it is your own fault." INOCULATION OB VARIOLA INOCULATA The practice of inoculation must be carefully distinguished from that of vaccination. By inoculation we mean the introduction of small- pox matter into the skin of man. The disease thus produced is usually mild, but is nevertheless true smallpox, and just as contagious as small- pox. This phase of the subject may be made clearer by considering small- pox as existing in three forms : ( 1 ) variola vera or true smallpox ; ( 2 ) variola inoculata or inoculated smallpox; (3) vaccinia, cowpox, or modi- fied smallpox. The differences between these affections are shown in the following table : Variola Vera Variola Inoculata Vaccinia or Cowpox True smallpox. Inoculated smallpox. Modified and attenuated smallpox. Only occurs in man. Occurs in man and monkeys. Man, monkeys, cattle, guinea- pigs, rabbits, rats, camels, and many other mammals. High mortality. Milder; rarely fatal; about 1 in 500. Very mild; never fatal. A general eruption, often confluent or hemor- rhagic. A local and a general eruption, fewer pustules (rarely over 200) ; seldom confluent or hemorrhagic. Always local and confined to the site of the vaccination. Highly contagious _ Equally highly contagious. Not contagious — contracted only by mechanical transfer of vac- cine virus. Period of incubation 12-14 days. 8 days. 3-4 days. 28 DISEASES HAVING SPECIAL PROPHYLAXIS Emphasis must be placed on the fact that variola inoculata, while usually a mild disease, is just as communicable as true smallpox, and those who contract the disease in this way get true smallpox, sometimes in serious or fatal form. Inoculation, therefore, protects the individiuil but endangers the community. Inoculation is a very old custom. It was practiced by the Chinese from time immemorial. The method was introduced into western civili- zation through Lady Mary Wortley Montagu, who learned of the method at Constantinople and had her own boy "engrafted" with successful re- sult. In 1717 Lady Montagu wrote her now famous letter to her friend Sarah Chiswell, and the practice soon became popular in England (1721) and spread to America and the Continent.^ It was introduced into this country by Dr. Zabdiel Boylston at Boston. But the dangers were early realized and inoculation was soon replaced by vaccination. According to Plehn, inoculation is still practiced in central Africa. The method of inoculation is precisely similar to that of vaccina- tion. The matter is obtained from the vesicle or pustule of a case of smallpox. This material is then introduced into the skin by means of a puncture, an incision, or through an abraded surface. The Chinese inoculate usually by plugging the nostrils with cotton previously sat- urated with a mixture of water and pustular-crustaceous matter taken from the eruption of a smallpox patient; less commonly by blowing the crushed fresh crusts into the nostrils through a bamboo pipe. Following the inoculation of smallpox virus a local eruption appears on the fourth day at the site of the inoculation. This local eruption resembles vaccinia but develops more rapidly. Constitutional symptoms appear on the evening of the seventh or the morning of the eighth day following the inoculation. These symptoms resemble the onset of true smallpox and are rigor, headache, vomiting, and fever. The local erup- tion subsides on the appearance of the febrile symptoms but at the same time the general eruption breaks out. The crop is usually discrete, mod- erate in number, but runs the usual course through papule, vesicle and pustule formation. While inoculation has properly fallen into disuse, there are con- ceivable emergencies in which the practice would be justified. For example, on board ship or on an island or isolated place, in the absence of vaccine virus. Under such circumstances it would be essential to inoculate everybody at the same time. The inoculation of smallpox will always remain for the student of preventive medicine one of the most interesting episodes in the develop- * The practice of inoculation had been published in England as early as 1714 by Dr. Timoni of Constantinople; at Venice in 1715 by Pylarini, and in the same year in London by Mr. Kennedy, a surgeon who had been in Turkey. Its adoption and subsequent diffusion, however, were due to Lady Marv Wortley Montagu. SMALLPOX AND VACCINATION" 29 ment of the sanitary sciences. It illustrates in the clearest manner some of the fundamental phenomena of infection, susceptibility, and immunity. It was animal experimentation on a huge scale, the like of which we shall never see repeated on man as the subject (Sedgwick). It is now a matter of regret that for the sake of science better advantage was not taken of the data. PREVALENCE OF SMALLPOX It is very difficult for us now to realize that smallpox was once much more common than measles and much more fatal. Many of those who recovered were disfigured for life, left blind, or with some other serious consequence of the disease. For centuries smallpox was one of the greatest scourges. It depopulated cities and exterminated nations. In Europe alone, where its ravages were comparatively slight, it killed hundreds of thousands yearly. In the 18th century, of which we have the best records, almost everybody had it before he grew up. Parents often exposed their children to the disease in order to be through with it, just as they now sometimes do with the minor contagious diseases. Smallpox was formerly a disease of children. It was called "kinder- bldttern." Since vaccination protects the child, smallpox has now be- come more prevalent among adults. The distinguished mathematician, Bernouille, estimated that 15,000,- 000 people died of smallpox in 25 years in the 18th century. It has been estimated that 60 million people died of smallpox during that century. Haygarth gives an account of a smallpox epidemic in Chester, England, population 14,713. At the termination of the epidemic there were but 1,060 persons, or 7 per cent, of the population, who had never had smallpox. Many similar instances are cited in the literature. The French physician de la Condamine (1754) said that "every tenth death was due to smallpox and that one-fourth of mankind was either killed by it or crippled or disfigured for life." Sarcone (1782) esti- mated the number of persons in Italy who suffered from smallpox as 90 per cent, of the population. Smallpox was introduced into the western hemisphere by the Span- iards about 15 years after the discovery of America. In Mexico within a short period three and one-half million persons are said to have died of the disease (Chapman). Catlin (1841) states that of 12,000,000 American Indians 6,000,000 fell victims to smallpox. In Iceland, in 1707, 18,000 perished out of a population of 50,000, that is, smallpox killed 36 per cent, of the total population in one year. A good example is that of Boston in 1752, population at that time 15,684. Of this number 5,998 had previously had smallpox. During the epidemic 5,545 persons contracted the disease in the usual manner, 30 DISEASES HAVING SPECIAL PROPHYLAXIS and 2,124 took it by inoculation. 1,843 persons escaped from the town to avoid infection. There were, therefore, left in the city but 174 persons who had never had smallpox. Smallpox is still as serious as it was in former times. Thus, in five years, from 1893-1897, 346,520 persons died of smallpox in sixteen countries. Of this number Russia alone lost 275,502. These figures are the more terrible when it is realized that these lives might have been saved by the use of a simple prophylactic measure within reach of all. EPIDEMIOLOGY Few of the acute infectious diseases show such a complete inde- pendence of conditions such as race, climate, soil, age, sex, and occu- pation, sanitary surroundings, etc., as does smallpox. It thrives wherever the contagion is carried, and wherever it finds susceptible people. Prob- ably no one is naturally immune. The susceptibility of an unvaccinated population varies, because a smallpox outbreak leaves so many immune. This is one reason why the disease recurs in waves. The mortality varies greatly in different epidemics. At times it is less than one per cent. ; it frequently reaches thirty per cent, and over. In 1901-1903 the mortality in the United States was as low as 2 per cent., and following that 0.5 per cent. These differences occurred in the prevaccination era as well as now. The epidemiology of smallpox bears no relation to improved sanita- tion, which has diminished the prevalence of tuberculosis, typhoid, cholera, and has practically subdued typhus and relapsing fever. It is evident that general sanitation could not affect contagious diseases like smallpox and measles. Smallpox spares neither high nor low, the rich nor poor; before the days of vaccination it counted many kings, queens, and princes among its victims. MODES OF INFECTION We are still ignorant of the precise mode by which smallpox is conveyed. The view generally held is that the infection is air-borne and enters the system through the respiratory mucous membrane. It has been surmised that a local lesion may be produced in this favor- able soil, the so-called "propustule," from which general infection through the blood takes place. The blood infection is marked by a sharp onset (the initial symptoms), and the skin eruption is embolic in char- acter. The objection to this view is that a careful search at 54 autopsies in Boston by Councilman and his colleagues failed to find such a pro- pustule. SMALLPOX AND VACCINATION 31 It is known that the Chinese inoculate the disease by placing a crust from the eruption in the nostrils, but the disease so produced resembles variola inoculata. The virus of smallpox is contained in the skin lesions. Of this we have experimental evidence. It is also supposed to be in the expired air. This, however, has never been experimentally proved and is doubt- ful. The disease is contagious before the eruption appears. It is even believed to be communicable during the period of incubation. Smallpox has always been taken as the type of the contagious diseases; the con- tagion is the most "volatile" of any of the diseases of man with the pos- sible exception of measles. This volatility, however, has been over- estimated, and, while probably an air-borne infection, the radius of dan- ger is contracted. English observers have long taken the view that smallpox may be blown for great distances, and they attribute the preva- lence of smallpox to the windward of hospitals as an indication that the virus may be carried down the wind. My experience with the disease teaches me that the danger from such a source is practically nil. One may safely live next door to a smallpox hospital that is well screened and properly managed. The influence of flies and other insects, or sur- reptitious visiting, may account for the spread of this disease outside of hospital walls. In addition to more or less direct contact, smallpox may be spread indirectly in a great variety of ways. The secretions from the mouth and nose doubtless contain the infection, and, while suspicion has not particularly fallen upon the feces and urine, it is probable that all the secretions and excretions from the body may be infective at some time throughout the disease, or during convalescence. Toys, pencils, spoons, cups, towels, handkerchiefs, bedding, and objects of the greatest variety that have in any way come in contact with the patient may carry the infection. Under favorable circumstances the active principle may prob- ably live for a considerable time upon fomites, although the practical danger from this source is not very great. Smallpox is not usually considered an insect-borne disease, but it is highly probable that a fly lighting upon a smallpox patient and get- ting its proboscis, feet, and other portions of its body smeared with the variolous matter, and then flying to a susceptible person, could thus readily transmit the infection. Other insects may by such mechanical transfer play a similar role. RESISTANCE OF TEE VIRUS It is generally, and doubtless correctly, assumed that the active principle of variola has approximately the same resistance to external conditions as vaccine virus. This assumption is confirmed by experi- 32 DISEASES HAVING SPECIAL PKOPHYLAXIS mental evidence, which shows that the virus of smallpox is somewhat more readily destroyed than the virus of cowpox. Scientific data con- cerning the viability of variolous matter is meager, owing to the fact that this question can only be settled by prolonged and repeated experi- ments upon monkeys. Brinckerhoff and Tyzzer^ found that variolous virus is less resistant to desiccation than vaccine virus; that variolous virus does not pass a Berkefeld filter and is attenuated by long exposure to 60 per cent, glycerin. Prolonged action of glycerin also destroys vaccine virus, but more rapidly at 37° C. than in the cold; if kept at from — 5° to — 15° C. glycerinated virus may remain active for years. In general it may be said that variolous virus is killed by exposure to ordinary germicidal substances, both liquid and gaseous, in the strengths and time commonly employed. It succumbs in fact before the average non-spore-bearing bacteria. TABLE 2- -DEATH-RATE FROM SMALLPOX AMONG VACCINATED AND UNVACCI- NATED IN VARIOUS COUNTRIES* Places and Time of Observation France, 1816-1841 Quebec, 1819-1820 Philadelphia, 1825 Canton Vaud, 1825-1829 Verona, 1828-1829 Milan, 1830-1851 Breslau, 1831-1833 Wiirttemberg, 1831-1835 Carniola, 1834-1835 Vienna Hospital, 1834 Carinthia, 1834-1835 Adriatic, 1835 Lower Austria, 1835 Bohemia, 1835-1855 Galicia, 1836 Dalmatia, 1836 London Smallpox Hospital, 1836-1856 . . . . Vienna Hospital, 1837-1856 Kiel, 1852-1853 Wiirttemberg (no date) Malta (no date) Epidemiological Society Returns (no date) Total No. of Cases Observed 16,397 ? 140 5,838 909 10,240 220 1,442 442 360 1,626 1,002 2,287 15,640 1,059 723 9,000 6,213 218 6,258 7,570 4,624 Death-rate per 100 Cases Among the Unvac- cinated 16.125 27 60 24 46.66 38.33 53.8 27.33 16.25 51.25 14.5 15.2 25.8 29.8 23.5 19.66 35 30 32 38.9 21.07 23 Among the Vac- cinated 1 1.66 2.16 5.66 7.66 2.11 7.1 4.4 12.5 0.5 2.8 11.5 5.16 5.14 8.25 7 5 6 3}^ 4.2 2.9 * Extract from papers prepared in 1857 by Sir John Simon, Medical OflScer of the General Board of Health of England, and at that time laid before Parliament with reference to the History and Prac- tice of Vaccination. Published in first Report of the Royal Commission on Vaccination, 1889, Appen- dix 1, p. 74. ^ "Studies upon Experimental Variola and Vaccinia in Quadrumana," Jour. Med. Research, Vol. XIV, No. 2, Jan., 1906, pp. 223-359. SMALLPOX AND VACCINATION 33 There is an exception to this statement in the case of carbolic acid and the coal-tar disinfectants. MeClintock and Ferry ^ have shown that such germicides as carbolic acid, cresols, and the like do not destroy the virulence of vaccine virus in 0.5 per cent, solutions in five hours' expo- sure. In this strength and time almost all non-spore-bearing bacteria would be destroyed. The inference is allowable that this class of disin- fectants cannot be relied upon to prevent the spread of smallpox. SMALLPOX IN THE VACCINATED AND UNVACCINATED The experience of over one hundred years offers convincing proof of the pronounced difference in the mortality and morbidity from small- pox in the vaccinated and the un vaccinated. The table on page 33 from Schamberg shows that, among thousands of cases of smallpox occurring in cities all over the world, the mortality from smallpox has been from five to sixteen times greater among the unvaccinated than among the vaccinated. In countries like Germany, Sweden, Ireland, Scotland, and England, where vaccination is more or less compulsory, there is comparatively little smallpox. In countries like Belgium, Russia, Austria, and Spain, which have no compulsory vaccination laws, smallpox yearly claims many vic- tims. See Table 1, page 26. THE RESULT OF VACCINATION IN GERMANY April 8th, 1874, Germany passed a general compulsory vaccination and revaccination law. The law requires the vaccination of all infants before the expiration of the first year of life, and a second vaccination at the age of twelve. Since this law went into effect there have been no epidemics of smallpox in Germany, despite the fact that the disease has been frequently introduced from without. In 1897 there were but 8 deaths from smallpox in the entire German empire^ — ^population 54,- 000,000. Since then long periods have passed without a single death from smallpox. From 1901 to 1910 there were only 380 deaths from smallpox in Germany; during the same period there were 4,286 deaths from smallpox in England and Wales, with only about half the popula- tion of Germany; furthermore, many of the deaths in Germany were in foreigners. Thus in 1909, out of 26 deaths from smallpox, 13 were foreigners, 11 of whom were Russians. In the huge German army there have been only two deaths from smallpox since 1874. One of these was a reservist who had not been successfully vaccinated. Germany has taught the world how to utilize Jenner's great demonstration. ^Jour. of the Amer. Public Health Assn., June, 1911 (Vol. I, No. 6), p. 418. 3 o o O "^ ^ o 2 § ° 3 O m o3 34 qo^ ££_ »6 4.6 969/. SB •±e_ ££_ ?g 469/ 06 jS£_ »P 4£_ 9£ff£ 9» M_ 2-^ ■■HI ■■■■■ ■■■■■ ■■■■■ ■■■■■ ■■■II ■■■II^^I^IIIIIIP"'"' mil Hill iiic: ::::: ::::: ::::: ::::: ::::: ::::: ::::: mil mil r'"" ■■■■■ ■■■■■ ■■■■■ ■■■■■ ■■■■m ■■■■■ ■■■■■ ■iiiiic:::::::!:::r::::::::!:!::::-":!::"::™^ 9 9 — a C.2 o -3 03 .2 s > >■ '53 ^5 ■liii iiiii mil mil mil imi iiiii iiiii —" ' ?a/2: mil Hill mil Hill iHii mil hiii r— — Z4 99ZS^ Uff/- Ol 69 99 t9_ 99fft 90 19 49P/. 6'ifr o'^f mil iiiii hiii hie: :-:■ !!!" _-!" "iv. '"". „"! t'ZZ ■^ it', iiii iV'y-^\i ^ a §•3 m 35 36 DISEASES HAVING SPECIAL riiOriiYLAXIS ISOLATION AND DISINFECTION Isolation and disinfection are only secondary measnres in prevent- ing smallpox. They cannot be regarded as substitutes for vaccination. Isolation should be carried out with strictness for the reason that smallpox is one of the most contagious of the communicable infections. While the patient should be isolated, it is not necessary to isolate the hospital by banishing it to an inconvenient or undesirable location. There is, in fact, no good reason why a smallpox hospital should not be one of the units of the general hospital for communicable diseases. In any event, there is no danger from a smallpox hospital situated upon a highroad or near other habitations, provided always proper precautions are taken to prevent the spread of the disease. The smallpox hospital should not be a pesthouse, but should be as inviting and attractive as economic conditions Justify. Smallpox, should not be treated in the home. From the standpoint of prophylaxis the hospital is the logical and best place to care for this and other communi- cable infections. If smallpox is treated in the home, this should only be permitted if skilled nursing and trained attendants can be provided. The room in which the smallpox patient is isolated should be simply furnished to facilitate cleanliness and to permit purification. It must be well screened and free from insects and vermin of all kinds. The room should be well ventilated. This may be accomplished by an open fireplace, in which case the contagium, if contained in the outgoing air, is burned in exit. The nurse attending a case of smallpox should also be segregated, and all visiting should be strictly interdicted. A separate kitchen should be provided and care should be taken that the dishes be scalded and remnants of food burned. Bedding, underwear, towels, and other objects should not leave the sick room unless they are first boiled, steamed, or immersed in a suitable germicidal solution, such as bichlorid of mercury, 1-1,000, or formalin, 10 per cent. Carbolic acid should not be trusted. For terminal disinfection either sulphur dioxid or formaldehyde may be used. Objects particularly contaminated or soon to be used by others should be given a separate and special disinfection. Finally, the room should be thoroughly cleansed, aired, and sunned. The patient must be regarded as the source and fountainhead of the infection, and measures should be used at the bedside to prevent the surroundings from becoming contaminated. Cloths, cotton, and other dressings that become soiled with the contents of the vesicles and pustules after they break should be burned. The urine and feces may be disinfected with chlorinated lime. The sputum and discharges from abscesses should be collected on cheap cloths and burned. As a rule. 1 § * ^ ^ 1 ^ ^ ^ 6^ "S. 1 ::.T : ^o 1 £o'0 ^oe/ i tiA'o 006/. 1 ff/^O ee 1 80'o ife 1 ftOO ze- 1 20'0 t9£^/ ( ^o'o S6 \90'0 *ire 1 £o ^e \'i'a He 1 eo /g»/ 1 t-'a 00 1 1' a e» 1 S'O 98^ 1 to <.» X S'O Afir^ XS'O S9 1 ♦'/ ■Ar» 1 -5-'/- ee ■ o'Z ^p II 9ff /e»/ II 9 2 op MS'Z €/. \ 1 et M X i.'o XI T 1 e'o Sl»t^ [f ""■;5-2;':";R5?2J3>5 K"*-'VA i/'p SZ J '^V'''.- ■^{'t, ^3'e ^Z ■ i"7^fe IHIIII ■■■■■■■ ■"liiiiii iiiiiiiiii ^ S S ^ J^ oo/^ \iZ''0 ooej^ \9'0 p'6 l**y' •if6 nil 1 O'Ol €€ 1 iiii 1 Yfa ^e ^''■'"'''*i^'' J!iU ''^'' '"■ 1 d'SZ • fbifA- J . _ 06 liiliittiiTtnftSSG iiii 1 e'^^z 69 1 |i^ii|4fl|4ff^^ nil I <'€9 »» .-.'■ ■ III 1 9'/9 4» ■ III 1 t.'tf/ ai»»A Ml i'M' ■ 1 III 1 z's» S9 '■ kill ' L'o9 ^/» III. 1 »'oS ep » - - i IT .--F--.. --..I!'!!! ■ Ill 1 yfes? ^p l4TTrmTTtiT7TTTr nil 1 »'iir6 -^^ SVA mill 1 1 1 ^'91 S9 1 1 1 9'Lfj /r9 1 1 ! ^^Z t9 Mllllll II 1 1 1 9'i'Z IP 1 II \\\9'U IS9t 1 II 1 1 ! e.'Al OS %\\l.'9l »ft 1 1 1 s'tz f,f)8/ T jii ii 1 1 1 o'sf. % I % t I ^ ^ 4 ^ ^ •:: 5 :='■>■-' rt .So -c o ^ 0) "T O q c3 3 (U > M tH CO .. m ^ a^ ^ £ §•- -S 2 "^ gy3 .3 to O O !z; " > > ^ £ o >i a ^ O 03 a p — I tH 13 ft S;3 +5 03 ® ia p-i 3 f-' S^ O O OS ■^ ; 3 S CO a; 03 1 2 '" O ^m j; '"' '3 P^ < 1—1 '^ BABIES 39 smallpox patients are not dismissed from quarantine until desquama- tion has ceased. This may be favored by the use of warm baths and a generous use of soap, also by anointing the skin with vaselin or a bland oil. Special attention should be given to the hair, which should be well shampooed; to the interdigital spaces, and the fingernails, as well as to all folds of the skin, before the patient is released. The management of a smallpox epidemic is discussed on. page 368. REFERENCES Jenner, Edward : "An Inquiry into the Causes and Effects of the Variolae Vaccinae, a Disease Discovered in Some of the Western Counties of England, Particularly Gloucestershire, and Known by the Name of the Cowpox." London, 1798. Brit. Med. Jour., May 23, 1896 (Jenner Centenary Number). Brit. Med. Jour., July 5, 1902 (Special Vaccination Number). Report of the Royal Commission on Vaccination. 1897. AcLAND, T. D. : "Vaccinia in Man." Allbutt and Eolleston's "System of Medicine," Vol. II, Part I, p. 665. 1912. CoPEMAN, MoNCKTON *. ^Tathology of Vaccinia." Allbutt and Rolleston's "System of Medicine," Vol. II, Part I, p. 746. Baron, John : "The Life of Edward Jenner, with Illustrations of His Doc- trines and Selections from His Correspondence." Vols. I and II, Henry Colbum, London, 1838. German Empire. Vaccination Law of April 8, 1874. Published in English. P. Paul, Berlin, 1904. ScKAMBERG, J. F. : "Vaccination and Its Relation to Animal Experimenta- tion." Defense of Research Pamphlet, No. 1. Am. Med. Ass'n. RABIES Synonyms. — Hydrophobia; Wasserscfieu, Wuth, ToUwuth (Ger- man) ; Lyssa (Greek) ; La Rage (French). Rabies is an acute, specific, rapidly fatal infection communicated from a rabid animal to a susceptible animal, usually through a wound produced by biting. Man always contracts the disease from some lower animal, usually the dog. The infective agent must be inoculated into the tissues; the virus is harmless when ingested, provided the mucosa is intact. The gastric juice has a pronounced deleterious effect upon the virus. Rabies may be regarded as a wound infection. The specific prin- ciple is contained in the saliva of animals suffering with the disease. The infection, therefore, may be conveyed by licking provided there are fissures or open wounds in the skin. It is also possible to introduce the virus through autopsy accidents and other unusual ways, but commonly it is introduced through wounds produced by the teeth of a rabid animal. Reference: "Facts and Problems of Rabies," Stimson, Hyg. Lab. Bull., No. 65, U. S. P. H. & M. H. S. 40 DISEASES HAVING SPECIAL PROPHYLAXIS Every mammalian animal is susceptible. Even birds may contract the disease. It is most common in dogs, but it also occurs frequently in wolves, jackals, foxes, and hyenas. Eabies in cats is comparatively rare. Cattle, sheep, and goats are infected relatively in about the same degree. It is less common in horses. Swine contract the disease less frequently than other domestic animals. Skunks may contract the disease and sometimes transmit it to man. Although all mammals are susceptible to rabies, it is perpetuated in civilized communities almost exclusively by the domestic dog, only to a small extent by wild animals of the dog family, and occasionally by skunks, cats, etc. Outbreaks have been reported under unusual circum- stances. Thus Carini ^ reports an epizootic believed to be rabies caus- ing the death of about 4,000 cattle and 1,000 horses in Sao Paulo, Brazil. There was no unusual prevalence of rabies in dogs at the time but it was noticed that bats, in broad daylight, attacked and bit the cattle, and Carini suggests that bats may have been the source of the extensive epizootic. The animals affected all died after a few days and the meat and hides were utilized but no mishaps have been known to follow. Eabies exists practically all over the world. It has never been in Australia, and has not been known in Denmark, Norway and Sweden for more than fifty years, and recently it has been practically eradicated from England. It is most common in France, Belgium, and Russia. In the United States 111 human deaths were reported in 1908. In the same year there were 535 localities in which rabid animals were reported; in 1911 there were 1,381 localities, and 98 deaths in man. In 1890 the United States census reported 143 deaths in 30 states, and in 1900 but 23 deaths. Rabies is remarkable on account of its high mortality — practically 100 per cent. After symptoms are pronoimced recovery rarely takes place. Joseph Koch (1910), however, describes an abortive rabies. The disease is peculiar in several other particulars, especially the period of incubation, which is more variable and more prolonged than that of any other acute infection. Rabies is commonly supposed to prevail only during the hot months, but it may be just as bad in cold weather. In fact, exposure to cold seems to increase its virulence. More cases occur from April to Sep- tember than from October to March in this climate, because dogs run abroad more freely at this season of the year. It is this fact, and not the temperature, that influences the prevalence of the disease. Period of Incubation.— From the standpoint of prevention it is for- tunate that the period of incubation of this disease is prolonged. This period varies from 14 days to a year or more. The average period is ^Ann. de I'Inst. Pasteur, Paris, Nov., XXV, 11, p. 785. EABIES 41 as follows: Man, 40 days; dogs, 21-40 days; horses, 38-56 days; cows, 28-56 days; pigs, 14-21 days; goats and sheep, 21-28 days; birds, 14-40 days. The period of incubation depends largely upon the site of the wound, the relation to the nerve, the amount and virulence of the virus. It requires about 15 days, counting from the last injection, to induce an active immunity to the disease by means of the Pasteur preventive treat- ment. There is, therefore, usually sufficient time, if the case is seen early, to prevent the development of symptoms. It is probable that the prolonged period of incubation is due in part to the fact that, although the living principle reaches the central nervous system, it remains dormant until favorable conditions permit multipli- cation and the production of toxic effects (Joseph Koch). Entrance and Exit of the Virus. — ^The active principle of rabies occurs principally in the saliva and in the central nervous system. It may be in the saliva at least three days (possibly eight) before the ani- mal shows symptoms (Eoux and Nocard). It is, therefore, sufficient to watch a dog that has bitten a person or another animal for ten days. If no symptoms of rabies appear during this time there is no danger of conveying the disease, and the Pasteur treatment is unnecessary. The virus may also be found in the adrenals, the tear glands, the vitreous humor, the spermatic fluid, the urine, the lymph, the milk, as well as all parts of the central nervous system and the peripheral nerves. It is also found in the spinal and ventricular fluids. It has not been demonstrated in the liver, spleen, blood, or muscles. The virus enters the system through the broken skin and follows the nerve trunks from the seat of injury to the spinal cord, thence to the medulla and brain. The route corresponds to that of tetanus toxin. The mode of invasion of the virus may explain why pain, throbbing, tingling, numbness and other nervous disturbances are the first symp- toms to occur in parts of the body that have received the virus. It also partly explains the variable period of incubation, which is shorter in wounds of the face than in wounds of the extremities. It also ex- plains why the disease is more liable to occur when the wounds are in parts of the body where there is an abundant nerve supply. Noguchi^ announces that he has succeeded in growing the virus, which appear in cultures as granular and pleomorphic chromatoid bod- ies, some of which are surrounded with membranes. Williams ^ and Moon ^ believe they have evidence of growth in brain tissue, having pro- duced rabies in animals in the fifth generation or transfer of such cultures. ^Noguchi, Jour. Exp. Med., 1913, XVII, 29. == Williams, Anna Wessel; Jour. A. M. A., 1913, LXI, 17, p. 1509. ^Moon, Jour. Infect. Dis., 1913, XIII, 232. 42 DISEASES HAVING SPECIAL PROPHYLAXIS The Relative Danger of Bites. — Wolf bites are most dangerous on account of the savage character of the wound, and the virulence of the virus. Cat bites come next, and then dog bites. The relative danger of bites of other animals is as follows : foxes, jackals, horses, asses, cattle, sheep, pigs. There is no authentic instance of the transmission of the disease by the bite of man, though this may be possible. The bites of horses and other herbivora are less dangerous because their blunt teeth usually cause contused wounds without breaking the skin. Bites on exposed surfaces are more dangerous than through the clothing, because the saliva is wiped from the teeth and little or none enters the wound. Long-haired dogs and sheep often escape infection for the same reason. Bites upon the face are most apt to be followed by rabies. Not every person bitten by a mad animal develops rabies. Leblanc's figures are 16.6 per cent. The statistics are difficult to analyze, and it is almost impossible now to collect sufficient data. According to the most reliable figures, it would seem that rabies develops in not less than one person in ten bitten by mad dogs, and not receiving the Pasteur treatment. Paltauf places the figures at 6 to 9 per cent. Viability. — The virus of rabies in the spinal cord of rabbits dies in about 14 days when dried at 20°-22° C, if protected from putrefaction and light. Spread in thin layers, it dies in 4 or 5 days, and exposed to the sunlight in 40 hours. It is quite resistant to putrefaction. In a decomposed carcass it may be recovered by placing some of the central nervous system in glycerin. The glycerin destroys most of the con- taminating bacteria, but preserves the virus. Eabic virus is completely destroyed at 50° C. in one hour, and at 60° C. in 30 minutes. It is not injured by extreme cold. Harris found the virus to be very resistant to dryness at low tem- peratures. Eabic virus in central nervous tissue is very resistant to ordinary germicides. Sawtschence ^ found that it requires from five to seven days to destroy the fixed virus in 5 per cent, phenol, and that it is not destroyed by 0,5 per cent, phenol in 20 days. Semple ^ found that the emulsion of fixed virus which resists the action of 1 per cent, phenol at room temperature for several days, succumbs in 24 hours at 37° C. According to Cummings ^ 1 per cent, phenol does not destroy the virus in 6 hours, while 2 per cent, solution kills it in less than 24 hours. On the other hand, most of the aldehyd compounds are very active in de- stroying the infectivity of the fixed virus. A 0.5 per cent, solution of salicylaldehyd, benzaldehyd, or furfurol destroys the virus in less than 3 hours. The specific disinfecting action of f ormaldehyd is shown by the 1 Sawtschence, W., Ann. de I'lnst. Pastev/r, 1911, XXI, p. 492. * Semple, "Sci. Mem. by Officers of Med. and San. Depts.," Gov. Ind., N. S., No. 44. ^Jour. Infect. Dis., XIV, 1, January, 1914, p. 33. EABIES 43 fact that the virus is destroyed when exposed for two hours to 0.08 per cent, solution. This indicates that formalin may be a useful sub- stance to treat dog bites, although experiments have shown that it is not as dependable as nitric acid. Bichlorid of mercury, 1-1,000, for 1 hour, or a saturated solution of iodin in water, completely destroys the virulence, and Wyrsykowski has shown that gastric juice has a pro- nounced deleterious effect upon the virus. PROPHYLAXIS The prevention of rabies is considered under three heads: (1) Treatment of the wounds; (2) the Pasteur prophylactic treatment, and (3) the control of the disease in dogs by muzzling and quarantine. The cauteriz'ation of the wound and the Pasteur prophylactic treat- ment are efficient preventive measures for the individual, but they are not the true and best methods of controlling and preventing rabies. Fig. 11. Chart Showing Relation of Enforcement of Muzzling Law to Prev- alence OF Rabies in Great Britain. The figures in the cross-patching indicate the number of persons who died of rabies_in England and Wales. The ordinates represent cases in dogs. (Frothingham.) The disease may be avoided, even exterminated, by an intelligent system of muzzling and quarantining of dogs. A high tax on dogs and leash- ing are only restrictive measures. In England, when the dogs were muzzled, rabies diminished. The law was repealed, owing to misplaced sympathy for the dog, and rabies promptly increased. The law was again enforced, and in about two years the disease disappeared (see Fig. 44 DISEASES HAVING SPECIAL PEOPHYLAXIS 11). Now a strict quarantine of six months is maintained against dogs entering England. It is no longer necessary to muzzle dogs in England, but muzzles will again be required should the disease reappear. Consistent muzzling of all dogs for two years will practically exterminate rabies. In Australia there are few carnivorous animals, mostly marsu- pials ; there rabies does not exist, for it has been kept out owing to early and effective quarantine measures. Norway, Sweden, and Denmark show good results and the same can be done in other peninsular regions. Prophylactic measures necessary to control the dog question are : the destruction of ownerless dogs; license fee and tag for all dogs; owners to be legally responsible for damage inflicted by their dogs; education of the dog-owning public concerning the spread of communi- cable diseases, especially rabies; compulsory reporting' of- all cases or suspected cases of rabies. Further special and temporary measures advocated are : muzzling ; restraint with chains, leash, etc. ; observation in quarantine, or killing of all animals bitten by dogs ; disinfection, etc.^ THE LOCAL TEEATMENT OF THE WOUND Wounds produced by the bite of an animal in which there is any suspicion of rabies should at once be cauterized with "fuming" or strong nitric acid. The acid is best applied with a glass rod very thoroughly to all the parts of the wound, care being taken that pockets and recesses do not escape. Thorough cauterization at once reduces the danger of wound complications, and experience demonstrates that wounds so treated at once are practically never followed by rabies. Marie obtained conflicting results with local treatment in experimental rabies ; Cabot ^ obtained the best results in a series of extensive experiments with nitric acid, and was able to save the lives of 91 per cent, of guinea-pigs by cauterization with nitric acid at the end of 24 hours ; Poor ^ saved 45 per cent., at the end of 23 hours. In the absence of nitric acid formalin or the actual cautery may be used. Strong antiseptics, such as carbolic acid, are not reliable. Nitrate of silver is valueless. In any wound produced by the bite of an animal cauterize unless sure that the animal is not mad. It has been shown that the virus may remain alive and virulent in the scar for a long time, and it has become a question whether patients seen after the wound has healed should not have the scar excised and the wound cauterized with nitric acid ; this, however, is not done now. . 1 In addition to rabies, dogs are responsible for other infections, such as hydatis, tapeworms (especially in children), round worms, tongue worms, and also fleas and ticks which transfer from the dog to man and which may in this way transmit diseases and parasites. "" Medical News, March, 1899. ^ Collected Studies, Research Lab., Dept. of Health, City of N. Y., VI. 1911, p. 25. EABIES 45 THE PASTEUR PROPHYLACTIC TREATMENT This method of prophylaxis was announced December 6, 1883, by Pasteur, at the International Congress at Copenhagen, and on February 24, 1884, he laid before the French Academy the details of his experi- ments and results. The next year Pasteur, with the help of Eoux and Chamberland, worked out the details of the method now in general use. The principle of the treatment consists in producing an active im- munity by means of an attenuated virus. The virus is attenuated by drying. The fixed virus contained in the spinal cord of rabbits dead of hydrophobia is the material used, for subcutaneous injection. Street Virus and Fixed Virus. — The distinction between fixed and street virus is of fundamental importance in reference to the question of immunity. Street virus refers to the virus obtained from mad dogs naturally infected. When this virus is inoculated into a rabbit, it re- produces the disease after a period of incubation of from 14 to 21 days or more. This street virus may then be conveyed from rabbit to rabbit through a number of transfers. In the passage from rabbit to rabbit the virus becomes more virulent for rabbits. The period of incu- bation is progressively shortened, until finally the rabbits invariably sicken on the sixth or seventh day and die on the ninth or tenth. When the virus has reached this degree of virulence for rabbits, it is said to be ''fixed," for the reason that its potency remains constant. In its pas- sage through rabbits the modification from street virus to fixed virus is gradual. It is important to note that fixed virus, which has attained a high degree of virulence for rabbits, has lost much of its virulence for dogs, and is probably a virulent for man. Proescher ^ injected into himself the entire brain and medulla of a rabbit (fixed virus), and another entire brain into a volunteer. No ill effects of any kind were noted in either case. A control rabbit in- jected with a 0.02 dilution of the same emulsion died in seven days with experimental rabies. Marx tested the fresh fixed virus upon monkeys in large doses, with negative results. Ferran in Barcelona in 1887 inoculated 85 persons with the fresh fixed virus as a prophylactic treatment for dog bites with good results, which have been further confirmed by Wysokowiez and ISTitsch. The evidence points clearly to the fact that the fixed virus of rabbits does not produce rabies in man when introduced into the, sub- cutaneous tissue. Preparation of the Virus. — Eabbits are injected under the dura mater with a few drops of an emulsion of fresh fixed virus obtained from the pons or medulla of another rabbit dead of hydrophobia. Strict ^N. Y. Med. Jour., Oct. 9, 1909, also Arch, of Int. Med., Sept., 1911, VIII, 3, p. 353. 46 DISEASES HAVING SPECIAL PEOPHYLAXIS aseptic precautions are necessary in order to keep out other infections. The rabbit should begin to show symptoms on the sixth or seventh day, and die on the ninth or tenth. Usually the rabbit is not allowed to die, but is chloroformed on the last day in order to avoid terminal infections and unnecessary suffering. The spinal cord is removed and hung in a bottle containing potassium hydroxid. These bottles are kept in the dark at a temperature of 20°-22° C. Under these conditions the cord gradually desiccates, and at the same time the virulence of the virus diminishes, until the fourteenth day, when it is no longer infective. This is why Pasteur started the treatment with a cord four- teen days old. One-half a cubic centimeter of the cord constitutes a dose. This is ground in sterile salt solution so as to produce a uniform emulsion, which is injected into the subcutaneous tissue of the abdominal wall. In many institutes the small segments cut each day from the drying cord are placed in pure glycerin. The virulence of the cord in glycerin is not altered for at least 30 days, if kept in the dark and at 15° C. This method, introduced by Calmette^ in 1891, based upon observation made by Hons in 1887,^ is very convenient, especially where comparatively few patients are treated. Glycerin has the added advantage of destroy- ing infections due to non-spore-bearing bacteria that may be present. As a further precaution, bacteriological examinations are made of parts of the spinal cord in order to insure the absence of bacteria, and the rabbit is carefully autopsied as a guarantee that no other disease is present. It is no longer necessary for persons to go to a Pasteur Institute for the treatment; the emulsion may be sent through the mail in a thermos bottle, or small segments of cord may be shipped in glycerin. The scheme of treatment advocated by Pasteur and still used at I'Institut Pasteur in Paris and many other places is shown on page 47. Many Pasteur institutes now use a modified treatment, starting with an 8-day instead of a 14-day-old cord, which is exemplified in the scheme used at the Hygienic Laboratory, Public Health Service, table, page 48. The scheme of Pasteur has been further modified in various ways, depending upon the method used to attenuate the virus. Thus Pasteur attenuated the virus by drying; Babes by heating; Frantzer by the use of bile ; Tizzoni and Cattani attenuated the virus in gastric juice. Hoy- ges used fresh material in a diluted suspension; Ferran fresh material and in increasing doses. Gumming altered the virus by dialysis. Harris dried the fresh virus at low temperature, which is used in diluted sus- pension. Other methods have been used to attenuate the virus, such as glycerin, carbolic acid, mechanical disintegration, and, lastly, antirabic ^Ann. de I'lnst. Pasteur, Paris, 1891, Vol. V, p. 633. "Ann. de I'Inst. Pasteur, Paris, 1887, Vol. I, p. 87. E ABIES 47 PASTEUR PROPHYLACTIC TREATMENT— RECOMMENDED BY PASTEUR Mild Treatment Intensive Treatment Amount of Amount of Day t of th Lge of e Dried Injected Emulsion Day of Age of the Dried Injected Emulsion ^ Treatment Cord 1 cm. to 5 c. c. Treatment Cord 1 cm. to 5 c. c. 14 Days 3 c. c. ^ \ ' 14 Days 3 c. c. 1 13 3 , 13 3 1 ^^ 3 11 3 [10 3 2 1 ri2 3 2 ^ 3 111 3 8 3 7 3 f 10 3 / 6 2 3 i I 9 3 3 \ 6 2 f 8 3 4 5 2 4 -! \ '^ 3 J ^ 6 2 5 5 2 ^ 1 I 6 2 6 5 2 6 4 2 7 5 2 7 3 1 8 4 2 8 4 2 9 3 1 9 3 1 10 5 2 10 5 2 11 5 2 11 5 2 12 4 2 12 4 2 13 4 2 13 4 2 14 3 2 14 3 2 15 3 2 15 3 2 16 5 2 16 5 2 17 4 2 17 4 2 18 3 2 18 3 2 19 5 2 20 4 2 21 3 2 serum. Ferran in Barcelona, Proescher in Pittsburgh, and others in- ject patients with the unaltered, fresh, fixed virus. The advantages of using the virus as fresh and strong as possible are that an active im- munity is produced more quickly, and this is of considerable importance in wounds of the face; also in wolf and cat bites, which frequently have a short period of incubation. Further, only one or two injections of the fresh virus are necessary to produce an immunity, and this shortens and simplifies the treatment very much. Harris ^ has shown that rabic material may be completely desiccated without destruction of virulence, provided the dehydration takes place at a low temperature. The lower the temperature the greater will be the amount of virulence preserved. Virus so desiccated contains per weight as much infectivity as the fresh virus. The virus thus dried is ^Jour. of Infect. Dis., May, 1912, X, 3, pp. 369-377. 48 DISEASES HAVING SPECIAL PROPHYLAXIS PASTEUR PROPHYLACTIC TREATMENT— HYGIENIC LABORATORY, WASHINGTON, D. C. Amount Ago of the Dried Cord Day Adult 5 to 10 Years 1 to 5 Years Scheme for Mild Treatment 1 8-7-6 2.5 c. c. 2.5c. c. 2.0 c. c. 2 5-4 2.5 2.5 1.5 3 4-3 2.5 2.5 2.0 4 5 2.5 2.5 2.5 5 4 2.5 2.5 2.5 6 3 2.5 2.5 2.0 7 3 2.5 2.5 2.0 8 2 2.5 1.5 1.0 9 2 2.5 2.0 1.5 10 5 2.5 2.5 2.5 11 5 2.5 2.5 2.5 12 4 2.5 2.5 2.5 13 4 2.5 2.5 2.5 14 3 2.5 2.5 2.0 15 3 2.5 2.5 2.0 16 2 2.5 2.0 1.5 17 2 2.5 2.0 1.5 18 4 2.5 2.5 2.5 19 3 2.5 2.5 2.5 20 2 2.5 2.5 2.0 21 2 2.5 2.5 2.0 Scheme for Intensive Treatmer.t 1 8-7-6 2.5 c. c. 2.5 c. c. 2.5 c. c. 2 4-3 2.5 2.5 2.0 3 6-4 2.5 2.5 2.5 4 3 2.5 2.5 2.0 5 3 2.5 2.5 2.0 6 2 2.5 2.0 1.5 7 2 2.5 2.5 2.0 8 1 2.5 1.5 1.0 9 5 2.5 2.5 2.5 10 4 2.5 2.5 2.5 11 4 2.5 2.5 2.5 12 3 2.5 2.5 2.0 13 3 2.5 2.5 2.0 14 2 2.5 2.5 2.0 15 2 2.5 2.5 2.0 16 4 2.5 2.5 2.5 17 3 2.5 2.5 2.5 18 2 2.5 2.5 2.0 19 2 2.5 2.5 2.0 20 3 2.5 2.5 2.5 21 2 2.5 2.5 2.0 SO stable that it may be standardized, permitting an accuracy of dosage hitherto impossible. The unit is the smallest amount which, when injected intracerebrally into a full-grown rabbit, will produce paresis RABIES 49 on the seventh day. The use of this desiccated virus in the prophylactic immunization of animals and persons offers many advantages over other methods and is gradually coming into use. Treatment at a distance from a Pasteur institute is now practical by sending a piece of cord, or the emulsion in glycerin, or the dry mate- rial in accordance with Harris' method. Care During the Treatment. — During the treatment the patient may go about his usual business. It is not necessary to stay in bed. The patient should, however, avoid fatigue, cold, emotional stress, trauma, and alcohol. It has been shown that these are important pre- disposing factors to the disease. It was found that customs' officers re- turning to the Siberian borders after prophylactic treatment for wolf bites showed an unusual mortality, which seemed to be due to exposure to cold. The disease has been observed to be brought on after a cold bath, falling into the water, and similar depressing influences. Complications of the Treatment. — The Pasteur prophylactic treat- ment may be complicated by (1) local reactions or (3) paralysis. Local reactions at the site of the wound are usually trivial. Ab- scesses, almost never occur. The local reactions consist of redness and induration. It is not necessarily the last injection, but rather the site of some previous injection that flares up. They soon subside without further trouble. This occurrence increases with the progress of the treatment; it is most frequent in the second week. As the treatment involves the introduction of a large quantity of foreign proteins into the body, it is probable that these reactions represent a phase of hyper- susceptibility. (See Anaphylaxis.) Paralysis. — Paralysis occasionally occurs and may be fatal. There is doubt concerning the cause of this paralysis, and a question whether it may be a mild or modifled type of rabies, or a form of anaphylaxis. In a case treated at the Hygienic Laboratory the paralysis came on 18 days after treatment, and was transient. H. E. Hazeltine ( Public Health Eeport, July 30, 1915, Vol. XXX, No. 31, p. 2227) reports two cases of paralysis following antirabic treatment, with one death. The New York Pasteur Institute reports a death from "ascending paralysis," which came on four days after the treatment. W. A. Jones ^ reported two cases with recovery. In 1905 Remlinger, head of the Constantinople Institute for Rabies, reported 40 cases of paralysis; Miiller found 16 cases in the literature, and had two of his own; Panpoukis, three cases; Jones, 2 ; making a total of 63, 2 of whom died. The Immunity. — Duration. — The immunity appears two weeks after the treatment and lasts a varying period of time, depending upon the individual — at least for several years. In this respect it does not differ from other instances of acquired immunity. The fact that the immunity Vow, A. M. A., Nov. 13, 1909, p. 1626. 50 DISEASES HAVING SPECIAL PEOPHYLAXIS appears on about the fifteenth day after the end of the treatment was discovered by Pasteur as a result of animal experimentation. The sta- tistics of the Pasteur Institute, giving the mortality from rabies in persons following the prophylactic treatment, exclude instances in which the disease develops within fifteen days after the last prophylactic injection. Nature. — 'The nature of the immunity is not clear. It certainly is not due to an antitoxin. Immune bodies are demonstrable in the blood twenty days after the last injection. This is determined by mixing in vitro the active virus with the blood serum, which neutralizes its activity. This neutralization is generally considered to be microbicidal or lytic in nature. Degree. — The degree of the immunity also varies, as is evidenced by the fact that a certain small percentage of the persons treated die of rabies. The Results of the Treatment. — Statistics giving the results of the treatment are somewhat difficult to analyze, as many factors are unob- tainable. Patients should be kept under observation at least a year. Exceptional cases occur one year following the treatment. Cases that occur within fifteen days after the treatment are excluded from the French statistics, for reasons that have already been stated. The figures on this basis show a mortality of less than 0.5 per cent. Better results are being obtained from year to year. The table on page 51 gives the general results at I'Institut Pasteur, Paris, since beginning the treatment. When we compare these figures with the fact that from 6 to 10 per cent, and sometimes 16.6 per cent, of all persons bitten by rabid dogs die of rabies, the prophylactic value of the Pasteur treatment is evident Some series of cases give a much higher mortality. Thus, of 855 persons bitten by mad dogs, collected by Tardieu, Thamehayn, and Bouley, 399 ended in death, or 46.6 per cent. In another series of cases given by Bouley, out of 366 persons bitten by mad dogs, 152 died of hydrophobia. But of these 120 were bitten on the face and hands, the greater danger of which has been mentioned. The mortality of bites from wolves is placed at from 60 to 80 per cent. Contraindications. — There are no particular contraindications to the treatment. All ages and conditions should be treated if exposed. Ap- parently no harm is done pregnant women. I have injected patients having malaria without trouble following. The treatment may be con- tinued in patients having colds, fevers, and other ailments without no- ticeable harm. Wh.en to Give the Pasteur Prophylactic. — It is sometimes difficult to decide whether the Pasteur prophylactic treatment should or should not be given. The treatment causes sufficient personal inconvenience, EABIES RESULTS OF TREATMENT AT L'INSTITUT PASTEUR. PARIS. 51 Year Percons Deaths Mortality 1886 2,671 25 0.94% 1887 1,770 14 0.79 1888 1,622 9 0.55 1889 1,830 7 0.38 1890 1,540 5 0.32 1891 1,559 4 0.25 1892 1,790 4 0.22 1893 1,648 6 0.36 1894 1,387 7 0.50 1895 1,520 5 0.38 1896 1,308 4 0.30 1897 1,521 6 0.39 1898 [1,465 3 0.20 1899 1,614 4 0.25 1900 1,420 4 0.28 1901 1,321 5 0.38 1902 1,005 2 0.18 1903 628 2 0.32 1904 755 3 0.39 1905 727 3 0.41 1906 772 1 0.13 1907 786 3 0.38 1908 524 1 0.19 1909 467 1 0.21 1910 401 0.00 1911 341 1 0.29 1912 395 0.00 1913 330 0.00 1914 373 0.00 not to speak of the danger (however slight) of paralysis, to avoid advis- ing it if unnecessary. In many cases it is impossible to discover whether the dog that inflicted the bite is mad or not. The rule in cases of doubtful exposure is to advise the treatment. Persons not infrequently apply for advice giving the following his- tory: They have not been bitten, but they have been licked on the hands and face by a dog that subsequently developed the disease. Per- sons are sometimes similarly exposed by washing the mouth of a rabid horse. In these cases the important question is whether there were fissures or abrasions in the skin at the time. There may be little wounds in the skin not evident to the naked eye. In such cases the danger is slight, but in apprehensive subjects the assurance of protection which the treatment affords is an important element in arriving at a decision. In all cases it is important to know whether the dog is mad or not. If the dog can be found and kept under observation for 10 days and no symptoms appear, the Pasteur treatment is not necessary. Animals killed early in the course of rabies may fail to show the microscopic 52 DISEASES HAVING SPECIAL PEOPHYLAXIS evidence of the disease, thus causing an indcfnjitc delay in diagnosis awaiting inoculation tests. Should the dog develop symptoms, the ques- tion of diagnosis is all-important. Diagnosis of Rabies in Dogs. — The diagnosis of rallies in dogs may be made in four ways: (1) from the symptoms; (2) from the presence of Negri bodies in the central nervous system; (3) from the lesions in the peripheral ganglia, and (4) by animal inoculations. 1. The symptoms may be very suggestive, but a diagnosis must always rest upon the pathological lesions and the inoculation tests. The course of the disease may be divided into three stages : a premoni- tory stage, a stage of excitement, and a paralytic stage. The first two stages may be absent or transient. All rabid animals invariably become paralyzed before they die. In dogs the first symptom consists solely in a change in the disposition of the animal. He is easily excited, but does not show a disposition to bite. Soon the restlessness becomes more marked, and the animal may become furious and even show signs of delirium. The animal does not fear water, as is commonly supposed, but rushes about attacking every object in his way. Dogs suffering from furious rabies have a tendency to run long distances (25 miles or more), often biting and inoculating large numbers of other animals and persons en route. Very soon paralysis sets in, commencing in the hind legs, and finally becomes general. The course of the disease is always rapid, averaging from 4 to 5 days, rarely exceeding 10 days. When the stage of excitement is brief or absent, the disease is known as dumb rabies. 2. There is a difference of opinion concerning the significance of the Negri bodies (Neuroryctes hydrophobiae) , which, however, are very constant in rabies and peculiar to it. If Negri bodies are found in the dog, the Pasteur treatment should be started at once. The absence of Negri bodies, however, does not necessarily mean the absence of rabies. These bodies are sometimes difficult to find, or may not be present in the parts of the central nervous system which are examined. Negri bodies are found especially in the horn of Ammon; they are 1 to 23 micra in diameter ; usually round or oval ; strongly eosinophilic ; occur within and without the nerve cells; and sometimes contain a nucleus ( ?). Negri bodies for diagnostic purposes are best demonstrated by im- pression preparations of Ammon's horn and cerebellum stained according to Van Gieson, as recommended by Frothingham; or smears stained in a similar manner as recommended by Williams and Lowden. Smears are prepared by placing a small portion of the brain matter near one end of a slide, crushing with a cover glass and spreading over the rest of the slide; portions are selected from Ammon's horn, cerebellum, cerebral cortex, and medulla. Impression preparations are made by pressing a THE VENEKEAL DISEASES 53 slide upon the cut surface of Amnion's horn, or other parts of the brain, and lifting with a quick movement. The chief advantage of this method is that the characteristic arrangement of the cells of the hippocampus (which rarely fail to contain Negri bodies) is undisturbed, and consequently desired cells are readily found and examined for bodies ; moreover, there is no danger of contaminating the fingers. Such impressions are: (1) fixed, while still moist, in methyl alcohol for one- half minute or longer; (2) stained with Van Gieson, while still moist with alcohol, steaming lightly for one-half to one minute; (3) washed under tap; (4) blotted with filter paper. Frothingham's modification of Van Gieson's stain is: Tap water 20 c. c. ; saturated alcoholic solu- tion fuchsin (f. Bac. Griibler) 1 drop; saturated aqueous solution methylene blue (f. Bac. Koch. Griibler) 1 drop. The stain remains good for three days. 3. The lesions of Van Gehuchten and Nelis, described in 1900, are the most characteristic anatomical changes. These lesions are found in the peripheral ganglia of the cerebrospinal and sympathetic systems, especially in the plexiform ganglia of the pneumogastric nerve, and the Gasserian ganglia. The normal nerve cells of these ganglia lie in a capsule lined with a single layer of endothelial cells. In rabies these endothelial cells proliferate and the nerve cells are partly or entirely destroyed and replaced by diverse cells associated with chronic inflamma- tory processes. 4. The final diagnosis of rabies rests upon animal experimentation. A small quantity of the suspected material is placed under the dura mater of a rabbit or guinea-pig. The diagnosis by this method, however, requires so much time (on account of the long period of incubation of the disease) that it is of no practical value in deciding whether or not the Pasteur prophylactic treatment should be given, but. in any critical case the positive evidence furnished by animal experimentation is incontrovertible. THE VENEREAL DISEASES As a danger to the public health, as a peril to the family, and as a menace to the vitality, health, and physical progress of the race, the venereal diseases are justly regarded as the greatest of modern plagues, and their prophylaxis the most pressing problem of preventive medicine that confronts us at the present day. No serious attempt was made by the sanitary authorities of any of our great cities to deal with this problem until New York City in 1912 ^ determined to treat the venereal diseases as any other highly 1 Resolutions adopted hj the Board of Health, February 20th. 54 DISEASES HAVING SPECIAL PROPHYLAXIS communicable and preventable infection, dealing purely with the sani- tary features of the problem from a public health standpoint, ignoring the social and moral phases. The opposition to such activity is slowly being broken down. Progress against the venereal diseases is a repeti- tion of the warfare along other lines of sanitation and hygiene. It is the history of a continuous struggle carried on in the name of law, religion, personal rights, or expediency. Although the difficulties in this case are much greater than in any other group of diseases, an intelligent and persistent campaign must end in a long-delayed success. Biggs states that in 1912 at least 800,000 people, or more than one- fifth of the adult population of New York City, have, or have had, some venereal disease, and that in a large percentage of these persons the disease is still active. The number of new infections occurring each year probably exceeds that of all other notifiable diseases combined. In view of such figures the magnitude and the importance of the problem of administrative control, as applied to these diseases, become clearly apparent. There are three venereal diseases : syphilis, gonorrhea, and chancroid. In order to have a clear understanding of the problems of venereal prophylaxis it is necessary to have a knowledge of the essential features of these preventable infections. Two of them, syphilis and gonorrhea, are of great importance, because they are very prevalent and because they are very serious infections with grave consequences. SYPHILIS There are many striking things about syphilis, but nothing so strik- ing as its persistence in spite of knowledge complete enough to stamp it out and in view of the popular dread in which the disease is held. It is preventable, even curable — ^yet scarcely another disease equals it in the extent and intensity of its ravages. It is one of the great cankers of humanity. Syphilis is a good illustration of the fact that it is much more diffi- cult to control a disease transmitted directly from man to man than a disease transmitted by an intermediate host, or one in which the infective principle is transferred through our environment. We have a certain amount of control over our surroundings, and we have dominion over the lower animals, but the control of man requires the consent of the governed. There is an accurate historical record of the startling spread of syphilis over the known world in a few years after 1495, and from that time it has everywhere been endemic. No similar record exists of the sudden establishment of any other great disease among the larger part of the earth's inhabitants. All evidence, however, points to the severe THE VENEEEAL DISEASES 55 character of the disease during this epidemic, the cases running an acute, febrile course, accompanied by symptoms of such severity as are now seen only in very unusual cases. Syphilis was unknown before the year 1493. It was probably brought by the crew of Columbus, on his first voyage from Espanola, or Hayti.^ Some of the returning crew accompanied Charles VIII of France in the Autumn of 1494 with the army, 32,000 strong, which invaded Italy for the conquest of Naples. The epidemic began in Italy at this time and the disease spread quickly over Europe with the scattering of the troops. Civilization and syphilization have been close companions, but syph- ilis is now less prevalent among civilized than uncivilized peoples — this is promising. Civilization, however, should not be content until it has controlled syphilis as effectively as it has a few other preventable infections. The effort to do so, at least, must be persistent and sincere. From the economic side, syphilis is not a serious disease in its pri- mary and secondary stages; that is, persons with syphilis during the early stages are usually not ill enough to cease work. Acutely fatal cases, such as frequently occurred in the sixteenth century, are now rare; in other words, the disease has lost much of its early virulence. It is the late manifestations, the sequelae and the so-called parasyphilitic lesions, as well as the inherited consequences of the disease, that play havoc. About one-fifth of all the insane in our asylums are cases of general paresis; 90 per cent, of these give the Wassermann reaction. Syphilis, alcohol, and heredity fill our insane asylums. The consequences of syphilis are often more severe upon the off- spring than upon the syphilitic parent. The infection itself, or various defects, especially of the nervous system, resulting from the conse- quences of syphilis, may be transmitted from parent to child, often with fatal results. When death does not ensue the results may be still more tragic. Syphilis is an infection caused by the Treponema pallidum (formerly known as the Spirochaeta pallida). It is a communicable disease ac- quired by direct contact with infected persons or things. It runs a chronic course with local and general manifestations, usually divided into three stages, which are not always well defined. The primary stage consists of the chancre which forms at the site of the initial infec- tion. The chancre is a hard indurated ulcer in the skin or mucous membrane, and appears about three weeks (not less than ten days) after the receipt of the infection. The secondary stage is characterized by a general invasion of the spirochete throughout the system, as indi- cated by a general involvement of the lymph nodes, eruptions upon the skin and mucous membranes, fever, anemia, and other indications of ^Jour. A. M. A., June 12, 1915, LXIV, 24, p. 1962. 56 DISEASES HAVING SPECIAL PKOPHYLAXIS a generalized infection. The third stage is character i zed hy a localized granulomatous growth known as a gumma, (iummata may appear in almost any tissue or organ of the body. A fourth stage is often added to the picture, consisting of the sequelae or parasyphilitic phenomena, such as general paresis, arteriosclerosis, locomotor ataxia, aneurysm, etc. Noguchi has recently demonstrated the presence of the treponema in some of these late lesions. The health officer should regard syphilis just as he does the acute febrile exanthematous diseases. Because syphilis runs a slow and often chronic course with mild constitutional symptoms during its early stages, it is often placed in a class by itself. This is a mistake. Syphilis has its period of incubation, eruption, and decline, just as measles and smallpox have. There is no natural immunity to syphilis ; all are susceptible, but the severity of individual cases varies greatly. This is due either to the virulence of the strain, the amount of the infection, or to variation in individual resistance. One attack of syphilis confers an immunity, in that reinfections do not produce another chancre. That is, the virus cannot be inoculated upon a person who has or has had the disease. If the disease is aborted by the timely use of salvarsan, reinfection may take place. The im- munity is peculiar in that, while the person cannot have a second chancre, this fact has no influence upon the development of the sec- ondary and tertiary lesions resulting from the first infection. For CoUes' and Profeta's laws of syphilitic immunity and the transmission of syphilis see page 503. In a large majority of all cases of syphilis the infection is trans- mitted during sexual approach. It is, therefore, spoken of as a venereal disease; many cases, however, are contracted out of venery. These acci- dental infections are more common than is ordinarily supposed. Metch- nikoff reports that a great number of cases of non-venereal syphilis occur among children in Eussia, where the peasants live huddled to- gether and in ignorance. Syphilis may be passed from one person to another by kissing, and the danger is greater when there are mucous patches or other open lesions upon the mouth. The disease may also be transmitted in wounds inflicted by the teeth of syphilitics. In sur- gery and midwifery practice physicians are not infrequently infected through minute abrasions — a pin prick or a scratch from a scalpel is sufficient to introduce the virus. Midwifery chancres are usually upon the fingers. Chancre of the lip is the most common of the erratic or extragenital forms, and may be acquired in many ways apart from direct infection, such as the use of spoons, glasses, pipes, etc., which have recently been mouthed by a syphilitic. The virus may also be trans- mitted by towels, clothing, razors, handkerchiefs, surgical and dental THE VENEEEAL DISEASES 57 instruments, human vaccine virus, etc. The list of articles that have conveyed the contagium is comprehensive. The spirochete of syphilis is a frail organism, yet it may live long enough on towels and other objects to command hygienic respect. Thus, Zinsser and Hopkins ^ found that pure cultures lived III/2 hours on a moist towel. Dried on covered slips, the spirochete failed to grow after one hour. Bronfenbrenner and ISToguchi ^ found that the viability of the spirochete is markedly diminished by lack of nutritive substances, presence of oxygen, effect of light and the toxic effect of sodium chlorid. Chancres of the mouth and on the tonsils result, as a rule, from per- verted practices. Wet nurses are sometimes infected on the nipple, and it occasionally happens that the relatives of a syphilitic child are acci- dentally infected. The hereditary and congenital transmission of syph- ilis is discussed on page 502. Syphilis lowers the standard of health and paves the way for other diseases. Whatever the etiological relationship may be, it is definitely known that syphilitics are prone to die early from affections of the heart and vessels, general paresis, diseases of the central nervous system (loco- motor ataxia), chronic nephritis, arteriosclerosis, aneurysm, apoplexy, etc. The actuaries of all life insurance companies know that the mor- bidity and mortality rates among syphilitics are very much higher than those of any other class of individuals of the community who enjoy ap- parent good health at the time of examination. Most insurance companies refuse to accept syphilitics at all. Some companies require extra premiums to compensate for the extra risks; a few companies will accept exceptionally favorable cases who have had a thorough course of treatment, and who have shown no symptoms for 3 to 5 years, but under these circumstances only special policies are contracted for which do not keep the applicant on the companies' books after 55 years of age. Syphilis is the chief cause of death in early adult life in persons otherwise hale and hearty. Osier estimates that between 6,000 and 7,000 persons succumb to syphilis each year in England and Wales, and he puts syphilis in a class next to tuberculosis, pneumonia, and cancer as a cause of death. Mat- tauschek and Pilcz ^ found that 4,134 officers of the Austrian army con- tracted syphilis between 1880 and 1900. Twenty died from the dis- ease, 198 had general , paresis, 113 have locomotor ataxia, 133 have cere- brospinal syphilis, and of this latter number 80 are insane. This gives a total of 14.64 per cent, of these better-class men dead or disabled as a result of syphilis. Syphilis was regarded as an infection peculiar to man until ISTicolle ^Jour. A. M. A., LXII, 23, June 6, 1914. ^Jour. of Phar. and Exp. Therap., Baltimore, March, IV, 4, pp. 251-362. ^Med. Klin., 1913, IX, 1544. 58 DISEASES HAVING SPECIAL PEOPHYLAXIS and Hamonic in 1902, and Metchnikoff and lioux jn 1903, transmitted the disease to the higher apes. Later it was found that monkeys and rabbits are susceptible. As a result of these experiments certain impor- tant facts in reference to prophylaxis were discovered. Metchnikoff and Eoux found that bichlorid of mercury, 1-2,000, applied one hour after inoculation, does not prevent the development of the primary lesion in the monkey. This is probably due to the fact that the action of the bichlorid is limited to the surface; it lacks penetration owing to its well-known property of coagulating albumin. Other antiseptics were tested, but in a long series of experiments, carried out on chim- panzees, baboons, and Macacus monkeys, Metchnikoff and Eoux showed that mercurial inunctions are most successful in preventing the devel- opment of the chancre. The mercurial inunctions may be made with metallic mercury, calomel, white precipitate (ammoniated mercury), or salicylarsenite of mercury. Calomel ointment appears to be the best, and is the one now generally used. It is rubbed up in lanolin in the proportions of 1 to 3 or 1 to 4. The ointment should be rubbed and left upon the place for 4 to 5 minutes and not later than 20 hours after the receipt of the infection. This will usually prevent the development of the disease. Excision, or destruction of the chancre with the actual cautery or with corrosive antiseptics does not influence the development of the disease. GONORRHEA Gonorrhea is much more prevalent than syphilis, and common opin- ion regards it as a mild and not very shameful disease, that is, "no worse than an ordinary cold." As a matter of fact, gonorrhea is one of the serious infectious diseases, and the gonococcus occupies a position of high rank among the virulent pathogenic microorganisms. From an economic and public health standpoint, gonorrhea does not fall very far short of syphilis in importance ; in fact, some give it first place. The serious consequences of gonorrhea are : complications such as periurethral abscess, gonorrheal prostatitis in the male, and vaginitis, endocervicitis, and inflammation of the glands of Bartholin in the female. Perhaps the most serious of all the sequelae of gonorrhea are those which result from the spread by direct continuity of tissues, such as inflammation of the Fallopian tube, and sometimes of the endo- metrium, the ovary, or even the peritoneum. The gonococcus has been found in pure culture in cases of acute general peritonitis. Other inflam- mations caused by the spread of the infection are cystitis, which some- times extends upward through the ureters to the kidneys. The gonococcus sometimes invades the blood and produces a general septicemia and pyemia ; death may occur from acute endocarditis. Gon- orrheal arthritis is, in many respects, the most damaging, disabling. THE VENEEEAL DISEASES 69 and serious of all the complications of gonorrhea. It may even follow ophthalmia neonatorum. It is more frequent in males than in females, but a gonorrheal arthritis of great intensity may occur in a newly mar- ried woman infected by an old gleet in her husband (Osier). The serious nature of gonorrheal complications in the eye will be considered separately under Ophthalmia N^eonatorum. Gynecologists tell us that the greater part of their practice is made up of the consequences of gonorrhea. Sterility is one of the serious consequences of gonorrhea. This may be caused in the male through epididymitis, which is a very common complication, and in the female by salpingitis, which closes or obstructs the Fallopian tube. Gonorrhea is said to be the cause of about one-half of all cases of sterility. Stricture of the urethra in the male is a fre- quent sequel. Gonorrhea is usually transmitted by sexual congress; however, acci- dental or innocent infections are not infrequent, especially in children. Gonorrhea in Children,. — Vulvovaginitis is common in children and is frequently due to the gonococcus. Outbreaks are common in schools, tenements, playgrounds, asylums, hospitals or wherever children con- gregate in considerable numbers and where the same lavatories, towels, nurses, etc., are provided in common. Paul Bendig ^ reports the follow- ing instance : Of 40 girls sent for convalescence to a brine bath, 15 showed signs of gonorrhea after the return. The infection came from an eight-year-old girl, who apparently had been suffering from gon- orrhea for several years, and was spread through indiscriminate bathing in one bath tub and the use of the same bath towel. Infants may contract the infection from the hands of the nurse. Towels, diapers, wash cloths, and bed linen may account for the trans- mission of the gonococcus in hospitals and asylums, although the rapidity with which the gonococcus dies when dried diminishes the danger some- what from this source. Diapers should always be disinfected by boiling or steaming before they are again used, especially in institutions. This, not only on account of gonorrhea, but infectious diarrheas. In the public bath children who use the same towel or soap run a great risk. The gonococcus may live a long time upon the surface of soap. Taussig ^ believes the seat of the water-closet favors the infection in little girls. These seats are usually too high and thus readily become smeared with the discharges from the vagina, and thus infect others. In schools and tenements the water-closets are often used by a stream of children one after another. Hence such seats should be low and U-shaped. The frequency of gonorrhea in children may be judged from the observations of Pollack, who reports 187 cases treated in the Woman's ^ Miinchener med. Wochenschr., 1909, p. 1846. 'Amer. Jour. Med. Sciences, CXLVIII, 4, Oct., 1914, p. 480. 60 DISEASES HAVING SPECIAL PROPHYLAXIS Venereal Department of Johns Hopkins Hospital duriiig the year 1909/ Pollack estimates that 800 to 1,000 cliildren are infected each year in Baltimore, and that the same proportion probably holds good for other cities. Seippel estimates that 500 cases occur annually in Chicago. One cause of the infection among children is the horrible superstition that a person infected with syphilis or gonorrhea may get rid of it by infecting another — especially a virgin. Gonorrhea in children due to rape is rare. When gonorrhea enters a children's hospital or an infants' home it is prone to become epidemic and is very difficult to eradicate. The story of the infection in the Babies' Hospital, New York, for eleven years, as told by Holt,^ illustrates the singular obstinacy of the infec- tion. In spite of the greatest care and precaution, there were, in 1903, 65 cases of vaginitis with 2 of ophthalmia and 12 of arthritis. In 1904 there were 52 cases of vaginitis, only 16 of which would have been recognized without the bacteriological examination. In all, in the eleven years, there were 273 cases of vaginitis; 6 with ophthalmia and 26 with arthritis. Holt urges isolation and prolonged quarantine as the only measures to combat successfully the disease (Osier). It is impossible to control such epidemics without bacteriological diagnosis aided by complement fixation tests. CHANCBOID Chancroid is a specific, local, auto-inoculable, and contagious venereal ulcer, caused by the streptobacillus of Ducrey (1889). The ulcers are often multiple and confer no immunity. Chancroids are local ulcers and, unless complications set in, cause no sequelae or general systemic effects, such as follow chancres. Chancroids, or soft chancres, are pe- culiarly liable to mixed infections. A little soap and water at the time of exposure is almost an absolute preventive against chancroid. If the ulcer has developed it may be aborted by cauterization, provided the chancroid is not more than three days old. Even when seven days old the ulcers may often thus be cured, but when more than a week old cauterization should not be em- ployed, for, if it fails, it leaves the sore larger than ever. The method of cauterization advised by Keyes consists in washing the ulcers with peroxid of hydrogen, drying, applying pure carbolic acid, then pure nitric acid, washing again with peroxid of hydrogen, and dusting with calomel. Chancroids are usually contracted in venery. The disease should not be regarded as a slight or negligible malady, for, on account of the mixed infections to which they are prone, serious consequences, and sometimes ^ Johns Hopkins Hospital Bulletin, May, 1909, p. 142. ''New York Med. Jour., March, 1905. . VENEEEAL PEOPHYLAXIS AND HYGIENE OF SEX 61 death, may result. The complications of the ulcers are various forms of phimosis, resulting from inflammation and swelling; destruction of the frenum; gangrene and phagedena; lymphangitis, with inguinal adenitis. The inguinal buboes are painful and frequently suppurate. Chancroid is usually given subordinate consideration because syphilis and gonorrhea are much more prevalent and much more serious. VENEREAL PROPHYLAXIS AND HYGIENE OF SEX The same principles apply to the prevention of the venereal diseases as apply to the prevention of other communicable diseases. The fight against venereal diseases, however, is especially complicated and difficult because of the close association with prostitution, the problems of sex hygiene, and alcoholism — in fact, the question pervades the woof and warp of society. There are three primitive appetites of man — hunger, thirst, and the sexual appetite. The first two persist throughout life; the last comes on at puberty, grows stronger during adolescence, and wanes with age. Any program for the control of the venereal diseases or the hygiene of sex must take into account the fact that we are deal- ing with a primal, impulsive, and natural passion which is the greatest force for social good, when used in accordance with the laws of nature, but may result in dire consequences when these laws are transgressed. The venereal diseases are among the most widespread and universal of all human ills, and enter more largely into the marring of domestic happiness than any other disease known to man. The difficulties of the situation should not deter the health officer and all those who labor for social uplift, for there is no more pressing problem in preventive medicine. Prevalence. — The prevalence of the venereal diseases among the popu- lation at large can only be approximated. Definite figures, however, are at hand for selected groups. The reports from the armies of the various nations give the following figures :^ VENEREAL INFECTIONS PER THOUSAND MEN Year3 Per Thousand X905-6 19 8 1906 28.6 1907 54.2 1906 62.7 1907 167.8 1 907 68.4 MVhite and Melville, Lancet, London, 1911, II, 1615. 63 DISEASES HAVING SPECIAL PEOPHYLAXIS Kober ^ gives a somewhat more recent and more detailed table. DIFFERENTIATED INFECTION PER THOUSAND MEN Syphilis Chancroid Gonorrhea U. S. Army 1909 U. S. Navy 1909 Japanese Navy 1907 British Navy 1908 British Army 1908 Japanese Army 1907 Prussian Army 1907 30.45 26.43 37.46 35.1 10.1 4.4 30.77 28.23 17.87 28.23 10.4 2.1 135.77 105.11 67.16 40.7 17.1 12.2 196.99 159.83 139.75 122.49 75.8 37.6 18.7 Both these tables indicate that the English-speaking people are, in their navy and military organizations at least, greater sufferers from venereal infections than the other nations. In civil life accurate figures are not obtainable. Cunningham ^ says that 60 per cent, of men acquire venereal infection some time. Ger- rish ^ estimates that 10 per cent, of the population of New York has syphilis. Eischer * guesses that 18 per cent, represents the syphilitic cases in the United States, and further, that there are 250,000 deaths each year due to venereal infection. Biggs ^ judges that there were about 200,000 cases of venereal disease in the city of New York in 1912. Mor- row ^ states that 75 per cent, of adult males acquire gonorrhea at some time, and that from 5 to 10 per cent, acquire syphilis ; these figures are based, not alone on his own observations, but on the opinion of such men as Neisser and Fournier. The pathologists of Melbourne, Australia, found syphilitic lesions in 30 per cent, of 200 necropsies; furthermore, 5 per cent, of the population within a ten-mile radius from the Mel- bourne postoffice were positive to the Wassermann test. Banks ^ states that we have nearly two and one-half million cases of venereal diseases occurring yearly in the United States — about one person in every forty. Attitude. — Our attitude, toward the venereal diseases is very incon- sistent. There is a natural aversion toward these afflictions. The sani- tarian should make no distinction between the venereal diseases and other epidemic diseases; he should regard the greatpox in the same light that he regards the smallpox. The principles for the control of syphilis and gonorrhea differ in no wise from those used to control ^ Kober, Tr. Assn. Am. Phys., Phila., 1911, XXVT, 155. "Cunningham, Boston Med. and Surg. Jour., 1913, LXVIII, 77. ^Gerrisli, "Social Diseases," New York, 1911, II, 1. * Fischer, PuUic Health, Lansing, Mich., 1913, VIII, 51. s Biggs, N. Y. Med. Jour., 1913, XCVIII, 1009. "Morrow, Boston Med. and Surg. Jour., 1911, CLXV, 520. Tub. Health Rep., Feb. 26, 1915, XXX, 9, p. 618. VENEEEAL PROPHYLAXIS AND HYGIENE OF SEX 63 smallpox, leprosy, tuberculosis, measles, diphtheria, etc. The health officer must not regard venereal disease as a punishment for sin and crime — the victim or culprit needs help and sympathy. The immediate problem is the prevention of further spread of the infection. A person afflicted with a venereal disease should be treated in the same humane spirit that actuates the physician in other diseases. Furthermore, the interests of the community require that the patient be accorded the best possible care and attention. The usual attitude toward the venereal diseases may well startle us when we consider that in most of our large cities no hospital will take a case of syphilis or gonorrhea during the acute stages, when these diseases are especially communicable. Morrow holds that the notoriously inadequate provision made for the reception and treatment of venereal patients is a disgrace to our civilization. For- merly lepers were segregated in vile lazarettos and cases of smallpox isolated in horrible pesthouses; now we have comfortable and congenial isolation wards or special sanatoria for these diseases. From the stand- point of prevention suitable hospital accommodations should be provided for those having venereal diseases. Education. — Education in sex hygiene and the venereal peril accom- plishes a certain amount of good. It may be questioned how much a knowledge of the consequences will prevent some persons committing crime. However, the old-style innocence must be regarded as present- day ignorance. Every boy and girl, before reaching the age of puberty, should have a knowledge of sex, and every man and woman before the marriageable age should be informed on the subject of reproduction and the dangers of venereal diseases. Superficial information is not true education. On the other hand, it is a mistake to dwell unduly upon the subject, for in many instances the imagination and passion of youth are inflamed by simply calling attention to the subject. One of the objects of education is to avoid the dangers of sex impurities, and all agree that this may often best be accomplished by keeping the mind clean, that is, away from the subject. The education must, therefore, be clear, pointed, brief, and direct. The object of educa- tion is not alone to help the individual to help himself, but to influence necessary legislation and concerted public action; also to lessen the influence of quacks. A simple knowledge of the facts is a sufficient deterrent for some; others may be influenced through fear of the con- sequences. Boys, as a rule, cannot be controlled through fear. The spirit of adventure is rife in healthy lads; they love to take a chance. Boys may be reached by an appeal to their better natures and by allu- sions to sister or mother. Instruction in sex hygiene should emphasize the rewards of strength and virtue, rather than the penalties of weakness and vice. The only foundation for a healthy sex life is an individual and social morality, 64 DISEASES HAVING SPECIAL PROPHYLAXIS combined with a knowledge and full understanding of sexual realities. The teaching of sex from a biological standpoint alone is inadequate, for there is little basis for character forming or ethical instruction in the physical analogies of animal and plant life. Instruction should be posi- tive rather than negative, constructive rather than destructive. The fear of disease or fear of anything else is not a sufficient motive for goodness. In contrast to the usual procedures, the emphasis should be placed on the beauty of goodness rather than on the ugliness of vice. In general, it may be said that the best plan of education in mat- ters sexual is to answer the questions of children upon the subject of maternity frankly and truthfully, but to offer them no information on the subject". The growing child at the age of puberty should be offered a certain amount of information concerning unnatural habits and should study physiology, biology, especially botany, and the facts of fertiliza- tion. At about the age of sixteen or eighteen girls as well as boys should be instructed as to the venereal peril. The person to impart the information may be parent, doctor, minister, friend, or teacher — in any event, two qualifications are essential: (1) Knowledge of the facts; (2) an impressive personality. As a rule the school-teacher is not naturally endowed nor is the class-room the best place to teach lessons in sex hygiene. The literature of the American Social Hygiene Asso- ciation, 105 West 40th St., Few York, is admirable. One circular is for young men, another for young women, and a third for those having venereal disease. Some of the facts all young men should know are: that the true purpose of the sex function is reproduction and not sensual pleasure; that the testicles have a twofold function, (a) reproduction and (b) to supply force and energy to other organs of the body; that occasional seminal emissions at night are evidences of normal physiological activity ; that sexual intercourse is not essential to the preservation of virility; that chastity is compatible with health ; and that the sex instinct in man may be controlled. The primary function of the testicles is to build the boy into the man. Castration in early life, as in the case of eunuchs, results in a loss of the internal secretion of the testicles and a failure in develop- ment of the secondary sexual characters which distinguish the male. There are an alteration in physical conformation and in the voice, lack of beard, development of the mamma, etc. — in other words, an approach to the feminine type. Healthy sexuality stimulates the imagination, sentiment, the esthetic sense, and the higher creative functions. Excesses or any influence which weakens the sexual system impair the will power, influence self-respect, and diminish mental force. Experience shows that arduous physical and mental labor, even after maturity is attained, is best performed when the sex organs are not exercised; that is, sexual VENEEEAL PROPHYLAXIS AXD HYGIENE OF SEX 65 excess distinctly impairs muscular strength and mental efficiency. It is unwise to frighten boys by exaggerating the results of self-abuse, which is rather the effect and not the cause of idiocy, insanity, degen- eracy, and other defects of the central nervous organization. Self-abuse is no worse in its effects than natural coitus, except for its influence upon character. Both are alike harmful when indulged in to excess. Eesults through education will be slow, for the aggressive conscience of the world in these matters has awakened too recently to have achieved as yet a great deal. Registration of Cases. — It is not possible to control any communi- cable disease, especially one that is pandemic, such as syphilis or gonor- rhea, without a knowledge of the cases and deaths. It is perhaps even more important to collect morbidity and mortality statistics of the great- pox than it is of the smallpox. But the public registration of private disease at once defeats its own object. Compulsory methods have here- tofore failed, and little may be expected from voluntary registration. When we consider that in our country we have no means of knowing the amount and distribution of smallpox, except to a limited degree in the registration area (which is less than one-half of our domain), what can we expect from the registration of the closely guarded secrets of the underworld? The public registration of ophthalmia neonatorum is successful because this form of gonorrhea is so apparent and the con- sequences so immediate and serious. The difficulties, however, need not deter us, and registration should be attempted even though the returns are incomplete. A start should be made, and, though the returns will be only partial at first, a gradual improvement may be expected. Every case known and properly cared for is a focus of infection neutralized. Continence. — One of the important facts to teach boys is that con- tinence is compatible with health. The testicles are like the tear glands and the sweat glands, in that they do not atrophy with disuse. Ben- jamin Franklin taught, as many another man of influence believes to-day, that the exercise of the sexual functions is necessary for health. This is a mistake and has done much harm. The sex principle is universal in nature. It is the force behind the constructive and progressive processes of all life, from the color adaptations of birds and flowers to the highest leadership in men. Ee- production is only one of its many functions ; and the man who assumes that the so-called physical desire that at times thrills him indicates a need of sexual intercourse is in danger of depleting and wasting from his life a chief source of physical and mental growth. The single standard for men and women must be insisted upon, and the parent or guardian is Justified in demanding a clean bill of health of the young man who proposes marriage. The young man, in turn, is entitled to the same from his prospective father-in-law. One of the 4 66 DISEASES HAVING SPECIAL PROPHYLAXIS defects of our artificial civilization which leads to harm is the post- ponement of the marriage age. To denounce youth as vicious when youth has merely followed the impulse of adolescence is futile, because youth will not believe this; other and juster reasons must be given, if youth is to listen and be controlled; and any young man, properly warned and properly in- formed will not be merely willing but anxious to learn from his doctor before marriage if he is fit to be a husband and a father. Carnal lust may be cooled and quelled by hard work of the body, as well as attention to personal hygiene — hence, one of the great ad- vantages of athletic sports for growing young men. Personal Hygiene. — Idleness, stimulating food, overeating, impure thoughts, evil associates, and alcohol excite the passions and are the bed- fellows of the venereal diseases. Purity of mind and cleanliness of body are helpful prophylactics. Physical exercise and an out-of-door life divert the mind and help the body ; it is a good safety valve for the excess animalism of youth. The public should be taught the necessity for thorough daily cleans- ing of the external genitals in both sexes, even in children. The large number of secreting glands and the decomposition of their secretions are liable to induce irritation and even minute lesions which open portals to infection of all kinds. Circumcision is recommended as an aid to genital cleanliness; as a prophylactic against syphilis and chancroid, venereal warts, herpes, and epithelioma, balanitis and phimosis; and also as a deterrent to mastur- bation. Alcohol. — The strongest indictment against alcohol is that it excites the passions and at the same time diminishes the will power. The fact that alcohol lowers moral tone does much more harm than all the cirrhotic livers, hardened arteries, shrunken kidneys, inflamed stomachs, and other lesions believed to be caused by its excessive use. Alcohol is not a stimulant, but depresses the higher functions of the brain from the beginning. See Index for references to Alcohol. Prostitution. — The regulation of prostitution by means of medical inspection has been tried and largely abandoned. In other words, it is a failure, for the reason that it makes vice easy and is therefore morally wrong. It gives a false sense of security and does no-t reach clandestine prostitution, which is the great source of the venereal diseases. Under certain limited conditions, such as in army encampments, where clan- destine prostitution can be eliminated, regulation has markedly dimin- ished the prevalence of venereal disease. The elimination of prostitution is beyond the dream of even the theoretical reformer. Its control resolves itself into questions of per- sonal hygiene and public hygiene ; it is inextricably mixed up with alco- VENEREAL PROPHYLAXIS AND HYGIENE OF SEX 67 holism, and, like the abuse of alcohol, the question may best be reached by that slower, surer process of improving the moral and physical fiber of man.^ Medical Prophylaxis. — In accordance with the researches of Metch- nikoff and Roux a reasonably efficient prophylaxis against the venereal diseases is now possible. Calomel ointment (331^ per cent.) applied within an hour of inter- course is generally effective in preventing syphilitic infection. There are several more or less efficient irrigations or ointments destructive to the gonococcus if used soon enough — the silver salts being the best. Prophylaxis is therefore possible, but it takes a great deal of care and vigilance, and the double method must be vigorously applied in order to be effective. It has been used with success in armies and navies, but in civil life, where strict routine and control of men are impossible, it is impracticable except in individuals ; even then it requires time, intelli- gence, and sobriety. In the United States Navy the following method is employed : The entire penis is scrubbed with liquid soap and water for several minutes, and then washed well with a solution of mercuric bichlorid, 1 to 2,000 in strength. If there are any abrasions present, they are sprayed with hydrogen peroxid from a hand atomizer. The man is then placed in a sitting position, well forward in a chair in front of a convenient re- ceptacle, and given two injections of a 10 per cent, solution of argyrol. He is required to retain each injection in the urethra for five minutes. After taking the injections, the entire penis is thoroughly anointed with a 33 per cent, calomel ointment. He is told not to urinate for at least two hours, and to allow the ointment to remain on the penis for some hours. A temporary dressing is placed on the parts to protect his clothes. The measures which will prevent gonorrhea will not ward off syphilis, and vice versa. The results attending such prophylactic treatment are very good. Thus Ledbetter ^ reports that at Cavite, before medical prophylaxis was instituted, the percentage of venereal diseases of all classes among the men averaged from 25 to 30 per cent, annually, and at times even higher. The percentage of gonorrhea was reduced to 8 per cent, annu- ally, and this percentage included about 30 patients who did not report for treatment. Chancroid was reduced from 5 to 2 per cent., which included 2 patients not reporting for treatment. Syphilis has been reduced from about 20 cases annually to one case for the entire year 1910, and this patient did not report for prophylactic treatment. The ^"The Social Evil in Chicago." Report by the Vice Committee, 1911. "Pros- titution in Europe," Abraham Fle.Kner (The Century Co.), 1914. ^Ledbetter, Robert E., "Venereal Prophylaxis in the U. S. Navy," Jour. A. M. A., April 15, 1911, Vol. LVI, No. 15, p. 1098. 68 JJJ8KASES HAVINC SP-KCJIAIv TIJOPHYLAXIS results speak for themselves and show tlie efficiency ol' the i>ioj)hylactic measures if properly and thoroughly carried out. Holcomb and Gather ^ report the following as a result of treatment used by them in 3,268 persons in the U. S. Navy between May 1, 1910, and August 31, 1911. The experience is considered to be a fair index of the results of medical prophylaxis. The treatment used by them is as follows: (1) Wash the penis, head, shank, and under frenum with 1-5,000 bichlorid of mercury solution with a cotton sponge. (2) Pass water. Take urethral injection of 2 per cent, protargol solution and hold to count GO. (3) Eub 50 per cent, calomel ointment well into foreskin, head, and shank of penis, with particular care about the fre- num. Treatment taken within eight hours after exposure in 1,385 cases shows 19 infections, or but 1.37 per cent. In the interval of from eight to twelve hours after exposure in 741 cases shows 25 infec- tions, or 3.31 per cent. Between twelve and twenty-four hours in 920 cases shows 4G infections, or 5 per cent. Of the 56 cases of gonorrhea occurring in the first twenty-four-hour interval, 26 were recurrent cases; the remaining 30 were primary infections. The use of salvarsan early in syphilis will prevent the further spread of the infection. Segregation. — Theoretically, every case of syphilis or gonorrhea should be isolated until the danger of infection is passed. Practically, however, segregation is impracticable except with a limited number of cases. With better and more attractive hospital facilities and free beds a certain amount of segregation may be accomplished voluntarily and humanely. An alert health officer can trace the source of infection in certain cases and induce the women responsible to take the salvarsan treatment in the case of syphilis, or to submit to hospital care in the case of gonorrhea or chancroid. Pontine circumcision and a medical examination as a necessary pre- liminary to marriage are further hygienic reforms advocated. Finally, in considering venereal prophylaxis, it should be remem- bered that these diseases are of great antiquity and seem likely to con- tinue indefinitely, that they already affect a large number of the popu- lation, and are spreading; that the existing means for the treatment of them among the poor is insufficient ; that the common mode of propa- gation is irregular and illicit intercourse; that prostitution arose in response to the strongest instincts and passions in the human breast; and that prostitutes themselves need protection and have claims on the humanity of the law. Furthermore, Lecky thinks that "The prosti- tute is ultimately the efficient guardian of virtue."' > Holcomb, Pv. C, and Gather, D. C. U. S. X.. "Study of 3,268 Venereal Prophylactic Treatments," Jour. A. M. A., Vol. LVIII, No. 5, Feb. 3, 1912, p. 368. PEEVENTABLE BLIXDXESS 69 PREVENTABLE BLINDNESS Preventable blindness is considered in this place because the largest single factor causing needless loss of eyesight is gonorrhea. Among the infectious eye troubles the most destructive is ophthalmia neona- torum. There are 64,000 registered blind persons in the United States. Of these about 10 per cent, (between six and seven thousand) are blind as the result of ophthalmia neonatorum. From 25 to 30 per cent, of all the blind children in all the blind schools of this country owe their infliction to gonorrhea. It has been estimated that probably one-half of the blindness in the world is preventable. Emphasis upon the great harm done by ophthalmia neonatorum should not blind us to the fact that there are other causes of blindness and eye deterioration which are preventable; thus we have to consider the later pus infections, also syphilis, smallpox, leprosy, sympathetic in- flammations, industrial accidents, accidents at play, progressive near- sightedness caused by violation of ocular hygiene, and a variety of inflammatory conditions. Functional disturbances of vision (amaurosis) and atrophy of the optic nerve may be brought about by poisoning with lead, alcohol, tobacco, and other toxic substances. This form of dimness of vision, or even loss of sight, occurs rather frequently, and in most instances is preventable. One of the common causes of impaired sight is phlyctenular keratitis, which leaves scars on the cornea. This condition is associated witli tubercular glands of the neck and is probably a form of bovine tubercu- losis, hence preventable. Trachoma is a menace to the integrity of sight. It is an infection caused by a virus,^ which is destroyed by heating for 3 minutes at 50° C. ; it may be preserved in glycerin 7 days.' The filtrability of the virus of trachoma remains undetermined. Ex- perimental evidence permits no more than the suspicion that the virus may be filtrable under some circumstances.^ In 1907 Prowaczek * de- scribed the so-called inclusion or trachoma bodies. The nature of these bodies and their possible etiologic relation to trachoma still remain un- determined. Lindner ^ described another form of these bodies but this ^ Bertarelli and Cacchetto, Cfentr. fur Bait., Orig., I Abt., Bd. XLVIII, 1908, p. 432, and Pathologica, 107, p. 1088, April 15, 1908. ^Nicolle, Cuenod and Blaizat, Comptes Rendu Acad. Sci., CLVI, April 14, 1913, p. 1177. ^Jour. A. M. A., LXIV, No. 12, Mar. 20, 191.5, p. 1000. * Halberstildter and Prowaczek, Deut. med. Wochenschr., 1007, XXXIIT, 128,5, Arb. a. d. k. (lesundheitsamte, 1907, XXVI. 44. ^ "Die freie Initialform der P. Einschliisse," Wien. Mm. Wochenschr., 1909, XLIX, 1697: Arch. f. Ophth.. 1910, LXXVI, 559. 70 DISEASES HAVINO SPECIAL PROPHYLAXIS has added little to our knowledge, Noguclii and ('ohcn ^ have recently, 1913, reported the successful cultivation of these Jnclusion Ijodie.s, hut since the cultivated bodies proved non-pathogenic the questi(ni still remains an open one. Trachoma flourishes best where sanitary conditions are worst. I'he control of trachoma consists in eliminating the foci of the disease, im- proving personal hygiene, and community sanitation. The disease is slow and insidious in its development. A mass of sago-lilce granulati(jns gradually fills in the retrotarsal fold, therel)y limiting the lid movements and leaving the eye half closed. The infection is rul)bed into the eye by roller towels, handkerchiefs, fingers, and other ways. When once estab- lished, the disease is chronic, and permanent cures are doubtful. Trachoma is much more prevalent in the United States than is ordi- narily supposed. The public eye clinics of Chicago are filled with pa- tients showing the resulting deformities. Wilder located a center in southern Illinois, and it has also been found in the mountains of Ken- tucky and Tennessee, while in Oklahoma this disease has become a public menace. It is more or less prevalent in the poorer sections of all the larger centers. Trachoma is of such a serious nature that all immigrants arriving at our shores have their eyelids everted and conjunctivae examined for evidence of this infection. An alien with trachoma is deported and the steamship is liable to a fine of one hundred dollars for bringing every ease of trachoma where it can be shown that the disease might have been recognized at the port of departure. Wood alcohol, Columbian spirits, methyl alcohol (CH^OH), cause blindness through atrophy of the optic nerves. As small a quan- tity as a teaspoonful has caused loss of vision. Blindness may even be caused by inhaling the vapor. Quantities as small as 0.2 per cent, in the inspired air may accumulate in the body and cause toxic effects. Wood alcohol is used as an adulterant, especially in liquors. Accidents. — In New York State about 200 industrial accidents re- sulting in total blindness occur annually. Besides this, there are a large number of accidents occurring on railroads in construction work, and in the field and forest. Many of the accidents to the eyes occurring in factories are pre- ventable. As a rule, the majority of such accidents are due to small flying particles. A material proportion of blindness is caused by accidents to chil- dren at play; sometimes the eyeball is torn by a buttonhook or pierced by a knife or awl ; or a scissors blade, used to untie a knot, slips. Some ^ "Experiments on Cultivation of So-called Trachoma Bodies," Jour. Exp. Med., 1913, XVIII, No. 5. PEEVENTABLE BLINDNESS 7.1 eyes have been injured by the crack of a whip, by a shot from an air-gun or toy pistol. Accidents also occur to the eyes from fireworks, especially on the Fourth of July. Ocular Hygiene, see page 706. OPHTHALMIA NEONATORUM Ophthalmia neonatorum or inflammation of the eyes of the new- born includes all the inflammatory conditions of the conjunctiva that occur shortly after birth — usually before the end of the first month. The conjunctivae of the newborn are peculiarly liable to infections. This delicate membrane rapidly acquires an immunity of a high order. The gonococcus is usually the cause of severe conjunctivitis occurring in a baby a few days old. The gonococcus has been demonstrated in 65 per cent, of all cases, mild and severe. Ophthalmia neonatorum is not always gonorrheal, but may be pro- duced by other virulent microorganisms or by irritating substances. The microorganisms other than the gonococcus that sometimes cause conjunctivitis during the early days of life are : streptococci, the menin- gococcus, the Koch- Week's bacillus, the pneumococcus, the diphtheria bacillus, and even staphylococci. These are relatively so rare that we may disregard their etiological significance for our present purpose. The diagnosis of gonorrheal ophthalmia may readily be made by simply examining a stained smear of the secretion. The infection commonly occurs during the passage of the child through the genital tract of the mother and usually just before deliv- ery. It is caused by the entrance of the vaginal secretion containing gonococci into the conjunctival sac. It may also be caused after de- livery by infected hands, towels, sponges, or other objects. The disease varies in severity; sometimes it is very mild, with slow onset and spontaneous recovery. Usually, however, it is severe and serious. The inflammation may extend from the conjunctiva to the cornea and invade the deeper structures of the eye. Corneal .ulcers and opacity may result, with complete loss of vision. In a typical case both the ocular and palpebral conjunctivae are red and very much swollen; the eyelids and surrounding tissues are infiltrated and there is a thick, creamy, abundant secretion. There are many grades of mild inflammatory condition, which must not be mistaken for gonorrhea. At birth the eyelids are almost always glued together with a normal sticky secretion. It is common, too, for the lids to remain red and sticky for a day or so. The diagnosis may be made in a few minutes by a microscopic examination. Prevalence. — Kerr calls attention to the fact that there are no com- plete statistics showing the prevalence of ophthalmia neonatorum, and only an approximate idea can be had of the number of cases by study- 73 DISEASES HAVING SPECIAL PROPHYLAXIS iiig the admissions to schools for tlio blind. A committee of the Brit- ish Medical Association found that more than one-third of those in blind schools of Great Britain owed their affliction to this disease.^ In the United States and Canada, in 1907, out of 234 admissions to 10 schools for the blind, 59, or 24.38 per cent., were blind as a result of ophthalmia neonatorum;- and out of 351 admissions to certain schools in the United States and Canada in 1910, 84, or 23.9 per cent., were blind from this cause.^ As a result of studies made of ophthalmia neonatorum in 10 man- ufacturing cities of Massachusetts, Greene has presented figures which show that the minimum morbidity rate for this disease was G.4 per 1,000 births. A more complete census made by him from the practice of 173 physicians in 9 cities revealed an average morbidity rate of 10.8 per 1,000 births.* It is estimated that the total annual loss from gonorrheal ophthalmia in the United States is seven million dollars, and that more than one million dollars annually is spent in partially caring for its victims. A blind child costs the community an excess of about $4,500 for its schooling. Prevention. — Ceede's Method. — Crede in 1881 introduced an effi- cient method of preventing ophthalmia neonatorum at the Lying-in Hospital at Leipzig, thereby connecting forever his name with the pre- vention of the disease and the subsequent saving of the sight of many infants. Crede's original method consisted sim^jly in placing one or two drops of a 2 per cent, solution of silver nitrate in each conjunctival sac, as soon as practicable after the birth of the head. In order to prevent gonococcic as well as other infections of babies' eyes, the following procedure is recommended : During pregnancy women should be instructed to practice daily external cleansing with soap and water and a clean wash-cloth. In case of any irritating dis- charge or even profuse white discharge, a physician should at once be consulted. Immediately after labor the eyelids should be carefully cleaned with sterile absorbent cotton or gauze and a saturated solution of boracic acid. A separate pledget should be used for each eye and the lids washed from the nose outward until quite free of all mucus, blood, or meconium without opening the lids. Next the lids should be separated and one or two drops of a 1 per cent, silver nitrate solution should be dropped into each eye, between the outer ends of the lids. The lids should be separated and elevated away from the eyeball so that a lake of silver ^British Medical Journal, May 8, 1909. 'Jour. A. M. A., May 23, 1909, p. 1745. ^Jour. A. M. A., July 1, 1911, p. 72. * Monograph Series of the American Association for Conservation of Vision, Vol. I, No. 1. PREVENTABLE BLINDNESS 73 nitrate solution may lie for one-half minute or longer between them, coming in contact with every portion of the conjunctival sac. One application only of the silver nitrate should be made, and ordinarily no further attention need be given to the eyes for several hours. Each time the child is bathed the eyes should first be wiped and cleaned with pledgets of sterile absorbent cotton wet with a saturated solution of boracic acid. Crede used a 2 per cent, solution of silver nitrate, but, as this is sometimes irritating, a 1 per cent, solution is now commonly employed, and seems to afford equally efificient prophylaxis. The silver nitrate solution should be instilled into each conjunctival sac but once. Re- located applications may cause serious inflammations. In fact, a single treatment sometimes causes a conjunctivitis, known as "silver catarrh.'' Because of the silver catarrh the strength of the silver nitrate solution has not only been reduced from a 3 to a 1 per cent, solution, but this may be neutralized after instillation with salt solution. Other prophy- lactic substances have been proposed. The best substitutes are a few drops of the newer silver compounds, as argyrol (25 per cent.) or protargol (5 per cent.). The following have also been recommended: Bichlorid of mercury, 1-3,000 or 1-5,000, silver acetate, 0.33 per cent., recommended by Zweifel, who used it in 5,333 cases. Schmidt and Rimpler recommend aqua chlorini. Carbolic acid (1 per cent.) or other antiseptics have also been tried. No substance, however, is known to be as reliable as silver nitrate, which should be used in all cases where there is any reason for believing that the mother is infected with the gonocoecus. If a conjunctivitis is present, a bacteriological examination of the discharge should at once be made. If the inflammation is due to the gonocoecus a 8 per cent, silver nitrate solution should be used. In cer- tain mild, non-gonorrheal infections 0.5 per cent, is usually sufficient. If the Klebs-Loeffler bacillus is found, diphtheria antitoxin should be given without delay. If the diplococcus is present, a weak solution (1 grain to the ounce) of zinc sulphate should be instilled frequently. As a general rule, it is advisable to use a prophylactic as a mat- ter of routine in hospital and private practice. To use Crede's method upon every case necessitates the unpleasant suspicion that every woman is a possible source of gonocoecus infection. If statements of the father about his previous life can be relied upon, an eye prophylactic can be safely omitted. In his private work Williams uses a boric acid solution except where there is special reason for believing that the mother has gonorrhea. The responsibility for risking the baby's eyes rests upon the medical attendant. There can only be one safe rule in case of doubt. It should be remembered that gonococcic infections of the con- junctiva occur in about one to every two hundred births (Edgar). 74 DISEASES HAVING SPECIAL PROPHYLAXIS The good results of Crede's metliod arc sndicionlly convincing to justify criminal proceedings upon those who fail to apply this simple prophylactic. liaab reduced the frequency of ophthalmia neonatorum in hospital practice from 9 to 1 per cent., while the statistics of many hospitals show only a very small fraction of 1 per cent. Stephenson's results are typical. In 2,265 births, ophthalmia neonatorum developed in 10 per cent, of the cases preceding the use of Crede's method. In 1,160 births after this method only 0.17 per cent, developed any trouble. A small number of cases may develop despite the use of silver nitrate. The technic of applying the nitrate of silver is very important, for, in the opinion of Edgar, when ophthalmia neonatorum develops after the use of nitrate of silver, it is due either to a secondary infection or to the fact that the solution does not really bathe the mucous membranes, but remains upon the lashes. The lids must be everted and the silver solution placed in the conjunctival sac either from a glass rod or a pipette. Care must be taken not to touch or injure the delicate mem- brane. Crede's method does not strike at the root of the evil. It would, of course, be much better to eradicate gonorrhea from men and women than to be compelled to drop silver nitrate into babies' eyes. Wrapped up wdth the question of ophthalmia neonatorum is the question of midwives, for to prevent blindness we must have intelligent and con- scientious obstetrical attendants, especially for the poor and ignorant classes. Midwifery practice needs regulation, supervision, and eleva- tion. Education is one of the bulwarks of prevention in this as well as other preventable infections. Legislation. — Ophthalmia neonatorum is an instance in which "the protection of the citizen from the assaults of ignorance, indifference, or neglect, wdien they threaten his well-being and even his economic efficiency, is a duty which the state cannot evade and which he has a right to exact." Laws for the prevention of the blindness of newborn infants are making progress slowly. Among the states in which the disease is notifiable are Connecticut, Massachusetts, Minnesota, Nebraska, New York, Oregon, South Carolina, Utah, Vermont, and Wisconsin. In some states the nurse, midwife, or parent is required to report the dis- ease, in other states the attending physician. Maine was the first state to take legal steps in 1891 to control ophthalmia neonatorum. In 1892 New York followed, with an amend- ment to the law relative to midwives and nurses. Subsequently most of the other states took legislative action.^ The provisions of the several ^Kerr, J. W., "OpTithalmia Neonatorum: An Analysis of the Laws and Reg- ulations Relating Thereto in Force in the United States," Fublio Health Bull. Ko. 49, U. S. P. H. & M. H. S., Oct., 1911. TETAXUS 75 ]a\vs are quite varied. In all of them, however, the object is to insure early treatment, and to this end compulsory notification is generally required. The health authorities of Massachusetts, New Jersey, Ver- mont, lihode Island, New York, and the District of Columbia furnish jDrophylactic outfits to physicians. The outfit ordinarily consists of a small vial containing a 1 per cent, solution of nitrate of silver, a steri- lized dropper and bulb, and a circular of instructions. In order to make material progress against ophthalmia neonatorum, as well as against infant mortality, it is essential that laws require prompt report of all births; it is the duty of the health authorities to see to it that such laws are efi^ectively carried out.^ TETANUS Compared with the major plagues of man, lockjaw has always been a rare disease. It is on account of the characteristic and fatal spasms that it early attracted attention. The student will be M^ell repaid by a study of the historical development of the theories that have been advanced since the time of Hippocrates to explain the cause of tetanus. These theories mirror the prevailing thought upon the nature of dis- ease as it developed from that of evil spirits, through the humoral theory, the realm of miasms and noxious effluvia, to the germ theory. Tetanus could not escajDe the rheumatism theory which has been such an alluring catchall for symptoms and diseases difficult of explanation. "Taking cold" was assigned its usual role here as elsewhere. When no assignable cause seemed at hand, the disease was given the learned title — idiojjathic tetaniis. Etiology. — In 1889, with the aid of anaerobic technic, Kitasato ^ for the first time grew the tetanus bacillus in pure culture, and by ^ The Massachusetts law reads as follows : Section 49. . . . Should one or both eyes of an infant become inflamed^ swollen and red, and show an unnatural discharge at any time within two weeks after its birth, it shall be the duty of the nurse, relative, or other attendant having charge of such an infant to report in writing within six hours-thereafter, to the board of health of a city or town in which the parents of the infant reside, the fact tliat such infiammation, swelling, and redness of the eyes and unnatural discharge exist. On receipt of such report, or of notice of tlie sann; symptoms given by a physician as provided by the following section, the board of health shall take such immediate action as it may deem necessary in order that blindness may be prevented. Whoever violates the provision's of this SECTION SHALL BE PUNISHED BY A FINE OF NOT MORE THAN ONE HUNDRED DOLLARS. Section 50. ... If a physician knows that ... if one or both eyes of an infant whom or whose mother he is called to visit become inflamed, swollen, and red, and show an unnatural discharge within two weeks after birth of such infant, he shall immediately give notice thereof in writing over his own signa- ture to the selectmen or board of health of the town; and if he refuses or neg- lects TO GIVE SUCH NOTICE, HE SHALL FORFEIT NOT LESS THAN FIFTY NOR MORE THAN TWO HUNDRED DOLLARS FOR EACH OFFENCE. (Revised Laws, Chapter 75.) ^ZeitsGhr. f. Hyg., Vol. VII, 1889, p. 225. 76 DISEASES HAVING SPECIAL I'KOI'll YLAX IS successful inoculation experiments pyoxcd tJiat tlii.s hacilliis was tlie real cause of tetanus. Kitasato further .showed tiiat tlie tetanus ha(,-ilhi.s is not found in the heart's hlood of mice dead of tcstanus, and therefore concluded that we are dealing with an intoxication, and not an infec- tion. We now regard tetanus as a type of the true toxemias. This work of Kitasato's was one of great importance, and led up to the epoch- making discovery of Behring and Kitasato ^ in the following year (1890) upon tetanus anxl diphtheria toxins and antitoxins, laying the founda- tion of serum therapy. Tetanus may he regarded almost solely as a wound complication. All wounds are not equally liahle to this complication, even though tetanus spores are present. Punctured, lacerated, and contused wounds are much, more susceptible to tetanus than cleancut or superficial wounds. The size of the wound is of much less consequence than its character. Fatal tetanus may develop from trivial wounds, such as pin scratches, small splinters, insect bites, vaccinations, etc. Symbiosis is an important factor in tetanus. Wounds infected with pyogenic organisms and other bacteria favor anaerobic conditions and permit the tetanus spores to germinate, and seem to encourage the growth of the bacillus and the development of toxin. ^ A few tetanus spores free of tetanus toxin in a clean wound may be taken care of by the phagocytic cells. This may readily be demonstrated experimentally by injecting animals with tetanus spores washed free of toxin. The normal habitat of tetanus is in the intestinal tract of herbiv- orous animals. Sanchez, Toledo, and Veillon ^ found tetanus in the feces of 4 out of 6 horses and in the feces of 1 of 2 cows. Park found tetanus bacilli in the intestines of about 15 per cent, of horses and calves living in the vicinity of New York City. They are present to a variable extent in the intestines of other animals and of man. It is rather a curious paradox that the horse, which is the most susceptible of all animals to tetanus toxin, is one of the principal hosts of the tetanus bacillus. The intestinal contents of certain animals offer ^particularly favorable conditions for the growth of tetanus bacillus ; such animals may be regarded as "tetanus carriers." The spores taken in the food are not affected by gastric digestion, and in the small intestines find ideal anaerobic conditions, food supply and temperature for growth and development. Here they may multiply and pass in the dejecta to pollute the soil. The soil, therefore, in all regions inhabited by man and domestic animals is more or less contami- nated with tetanus. The bacilli, however, do not multiply in the soil. While the soil acts only as a vehicle, it is the immediate source of the ^Deutsch. med. Wochcns., Vol. XVI, No. 40, p. 1113. ^ In tlie laboratory some of the strongest tetanus toxins have been prepared from mixed or contaminated cultures. ^La Semame Med., 1890, X, p. 45. TETANUS 77 large proportion of tetanus in man. Tiio proscnee of tetanus spores in soil, street dust, fresli vegetables and on clothing and the skin may be traced to fecal contamination. On account of the great resistance of the spores, they are blown about in dust and are spread everywhere by dirt and manure. Tetanus has been found in hay dust, on horses' hair, in the dust of houses, bar- racks, and hospitals, in the mortar of old masonry, in street dust, in gelatin, and in the greatest variety of places. One of the agencies in the distribution of tetanus spores over lim- ited areas is undoubtedly the common house fly. The poisoned arrow- heads of certain savages in the Xew Hebrides contain tetanus spores obtained by smearing the arrowheads with dirt from crab holes in the swamps (Le Dantic). Tetanus bacilli are not equally numerous in all localities. The in- fection is much more prevalent in warm than in cold countries. It is especially severe in the tropics, yet Iceland at one time sutfered severely from tetanus neonatorum. Some parts of Long Island and Xew Jersey have become noticeable for the number of cases of tetanus complicating small wounds. Tetanus spores are widely disseminated in India. Good- rich states that in Bombay alone there were 1,955 cases of tetanus in five years. These do not include the jjuerperal cases. Tetanus occurs eitlier sporadically or in epidemic form. Formerly epidemics in hospitals (especially in lyi]ig-in liospitals) and in wars were rather common. The conditions of trench M'arfare now going on favor wound complication, including a frightful amount of tetanus. Before the days of antisepsis the infection was readily spread through instruments, fingers, bandages, etc. Trismus neonatorum, or tetanus of the newborn, was a common and very fatal infection, especially in the tropics. Before the days of asepsis the infection was permitted to enter through the umbilical wound. In certain of the West Indian islands more than one-half of the mortality among the negro children has been due to this cause. Since the introduction of proper methods of treating the cord the disease is rare. The wounds produced by blank cartridges are especially liable to develop tetanus. The source of the tetanus spore in these cases is not entirely clear. Wells examined 200 cartridges from five firms without finding the tetanus bacillus. It is probable that the spore is upon th€ skin and is carried along with the paper and powder from the blank cartridge. The peculiar character of the wound favors the develop- ment of tetanus. The great decrease in the number of cases of tetanus following Fourth of July wounds is due to the vigorous campaign carried on by the American Medical Association. In 1903 there were 40G deaths 78 DTSP]ASES HAVING SIM^XUAI. I'llOl'll VLAX IS from tetanus; in 1904, 91; 1905, 87; 190G, 75; 3 907, 73; 1908, 70; and in 1911 only 18 cases and 10 deaths. Eighty per cent, of these followed blank cartridge wounds. The good results are attributed to the more thorough and careful treatment of the wounds and especially the use of tetanus antitoxin as a prophylactic — and more recently tti safer and saner methods of celebration. Tetanus spores or toxin may contaminate bacterial vaccines, anti- toxic sera, vaccine virus, and other biologic products used in human therapy. The possible association of tetanus with bacterial vaccines A\'as demonstrated in the unfortunate outbreak at Mulkowal, India, in 190"i.^ One hundred and seven persons were inoculated with Haffkine's plague prophylactic. Of these 19 were affected with symptoms of tetanus and died. In this case the tetanus probably grew as a contamination in the plague culture, for it is now well known that the anaerobic conditions produced in B. diphtJieriae, B. pestis, B. suhtilis, and other organisms in liquid culture media favor the growth of tetanus and the development of its toxin. In St. Louis (1901) diphtheria antitoxin was taken from a horse during the j^eriod of incubation of tetanus and used in amounts from 5 to 10 c. c. upon 7 children, all of whom died of tetanus. Bolton, Fisch, and Walden ^ found that the serum was sterile, but contained tetanus toxin in considerable amount. If the serum had first been tested upon animals, its poisonous properties would have been discov- ered. This test is now required by the United States law of July 1, 1903, for all serums and vaccines sold in interstate traffic. As a fur- ther precaution against this complication horses undergoing treatment for the production of immune sera are given prophylactic doses of tet- anus antitoxin from time to time. Tetanus sometimes occurs as a complication of vaccination (see page 22). It is, of course, not the rust on a nail that is dangerous, so far as tetanus is concerned, but the spore-bearing dirt it carries into the deep, contused wound that causes the trouble. Gelatin may contain tetanus sjDores, and the subcutaneous injection of imperfectly sterilized gelatin as a hemostatic has sometimes resulted in accidents. Tetanus is harmless when taken by the mouth. Susceptible animals may be given enormous doses of tetanus toxine by the mouth without producing the disease. The bacillus and its spore may be regarded as a saprophyte in the intestinal tract. There is, however, a suspicion that tetanus spores sometimes invade the organism through small wounds in the digestive or respiratory tract. Perhaps some of the cases follow- ing surgical operations may be accounted for in this way rather than by infection of the catgut used for ligatures. ^Jour. Trop. Med. and Hyg., 1907, X, p. 33. 2 Bolton, Fisch, and Walden in Ht. Lovis Medical Revieiv, Vol. XLIV, No. 21, Xov. 2?,. inin. p. :^.(>i. TETANUS 79 TctaiiiKS sometimes oeeurs in which no wound can be found. 'I'liis is the so-called "idiopathic or rheumatic tetanus." One explaijatiou of these cases is to be found in the fact that the spores are numerous in street dust and may enter the respiratory tract. They cannot do harm so long as the mucous membrane is healthy, but may enter through inflamed memJbranes or through small vwunds in the nose. Tetanus bacilli have been found in the bronchial mucus of idiopathic cases. Tet- anus spores have recently been found in the lymph glands, liver, and other parts of the body, upsetting our previous view that they are strictly confined to the site of the wound. These spores may remain latent for a long time, awaiting favorable conditions to grow and produce toxin, thus giving another plausible explanation of some cases of idiopathic tetanus. Incubation. — The period of incubation in man is usually from 6 to 14 days. The period is directly proportional to the amount of toxin and the severity of the disease. This can readily be demonstrated upon susceptible animals. In a study of 600 serial tests, Eosenau and Ander- son found this direct relation between the period of incubation and the severity of symptoms by the subcutaneous injection of varying amounts of toxin into guinea-pigs. Thus, guinea-pigs receiving fairly large doses showed symptoms on the third day and usually died, a very small percentage recovering. The smaller the dose the longer the period of incubation and the milder is the disease, and the greater the chances of recovery. With a short period of incubation, 6 days or less, the disease in man is almost invariably fatal. With longer periods the disease is milder and recovery frequently takes place without the use of antitoxin or other measures. Tetanus toxin travels up the axis cylin- ders of the nerves to the cord and brain. It is also distributed in the blood. The period of incubation, therefore, depends somewhat upon the point of entrance of the poison and its proximity to large motor nerve endings. Resistance. — The tetanus bacillus is readily destroyed by all the or- dinary agencies that kill spore-free bacteria. It is killed almost at once in contact with the free oxygen of the air. On the other hand, few, if any, forms of life have a greater resistance than the tetanus spore. Hours of exposure to 60° or 70° C. do not affect them. They usually survive an exposure of one hour to 80° C, but, as a rule, are killed in streaming steam or boiling water in 60 minutes. Tetanus spores, how- ever, vary greatly in the power to resist the boiling temperature. Ivita- sato ^ found them to resist 80° C. for one hour, but to be killed in streaming steam in 5 minutes. Vaillard and Vincent ^ found that the spores heated in the presence of moisture in a closed vessel would resist ^ Zeitschr. f. Hyg., VII. p. 225. ^ Ann. de I'lnst. Pasteur, 18D1, V, p. 1. 80 DISEASES HAVINCt SPECIAL IMiOPHYLAXlS destruction at 80° C. j'or (i liours, at 90° C. for )l Jiolu'.s, uud 100° C. 3 to 4 minutes, that they were not always destroyed in ■> minutes, hut never resisted more than 8 minutes at 100° C. Levy and Bruns ^ found that destruction hcgins at 81/^ minutes at 100° C. ; after 15 miuuies few survive, after 30 minutes none. Falcioni ^ studied the suhjcct in view of tlie dangers of the suhcutaneous injection of gelatin. Jle im- pregnated gelatin with spores of tetanus bacilli grown in agar or broth for 10 to 12 days, and used Koch's steam sterilization. He found the spores to resist destruction for 2i/2, but not for 3, hours in streaming steam. The experimental results are, therefore, sufficiently varied and con- flicting to suggest that races of tetanus bacilli exist, the spores of which vary widely in their resistance to moist heat at 100° C. Theobald Smith ^ found that under certain conditions of cultivation some tetanus spores survive a single boiling or streaming steam for 20 minutes reg- ularly, usually for 40 minutes, and occasionally for 60 minutes; in one case 70 minutes' exposure did not destroy the spores. He also showed the possibility of tetanus spores surviving in culture fluids sterilized by discontinuous boiling or steaming in routine laboratory work for fully 20 minutes on three successive days. Tetanus spores resist the action of 5 per cent, carbolic acid for 10 hours, but are killed in 15 hours. A 5 per cent, solution of carbolic acid, however, to which 0.5 per cent, of hydrochloric acid has been added, destroys them in 2 hours. Bichlorid of mercury, 1-1,000, kills the spores in 3 hours, and in 30 minutes when 0.5 per cent, of hydro- chloric acid is added to the solution. According to Park, silver nitrate solution destroys the spores of average resistance in 1 minute in 1 per cent, solution, and in about 5 minutes in a 1 to 1,000 solution. Tetanus spores are destroyed with certainty when exposed to dry heat at or above 160° C. for one hour, or to steam at 120° C. for 20 minutes. En- tire confidence may be jDlaced upon either of these two methods. Direct sunlight does not kill the spores, but seems to diminish their virulence. Under certain circumstances they may live a very long time ; Henrijean rej^orts that, by means of a splinter of wood Avhich once caused tetanus, he was able after 11 years again to cause the disease by inoculating an animal with the infective material. Prophylaxis. — Local Treatment of Wounds. — Wounds, however in- significant, should be thoroughly cleansed. Punctured or lacerated wounds in which there is special danger of tetanus should be freely opened, and every particle of foreign matter carefully removed. Prompt- ness in cleansing the wound surgically is almost as important as thor- oughness. Wounds containing garden earth, street dust, or other mate- * Grenzgeb. d. Bled. u. Chir.. 1902. X, p. 235. " Annali d'igiene sperimentale, 1904, N. S., XIV, p. 319. ^Jour. A. M. A., March 21, 1908, Vol. L, pp. 929-934. TETANUS 81 rial liable to contain tetanus spores should receive special consideration. After laying open and thoroughly cleansing such wounds, it may be ad- visable to disinfect them with the actual cautery or strong chemical agents. For this purpose nitric acid, carbolic acid (from 25 per cent, to pure), or formalin in full strength may be used. Silver nitrate destroys the tetanus spores in laboratory experiments, but lacks penetration in the presence of albuminous matter. It is sometimes good practice to totally excise the wound, and even amputation must be considered in certain cases. The division of the umbilical cord and the treatment of the navel in the newborn must be done under the strictest asepsis. All wounds in which there is any suspicion of tetanus should be kept open and freely drained, and otherwise treated so as to discourage anaerobic conditions. Tetanus spores gain entrance into wounds not only from manure, garden soil, street dust, and similar sources, but also from the hands, instruments, bandages, suture material, or other objects. It is impor- tant to remember that the tetanus spore is exceedingly resistant to heat and chemical agents, and that in surgical and obstetrical practice con- fidence should not be placed simj^ly upon brief boiling to destroy the spores. Very particularly care must be exercised in the disinfection of substances injected into the body, such as gelatin and other organic materials. For the destruction of tetanus spores complete confidence may be placed in the autoclave, in which a temperature of 120° C. for 20 minutes is attained, or exposure to dry heat at 160° C. for 1 hour. It should be remembered that tetanus toxin is manufactured in the wound and is thence transported mainly along the nerve roots to the spinal cord and brain. It is therefore important to destroy or neutral- ize the toxin in the wound. For this purpose dry tetanus antitoxin may be dusted upon the wound. Formaldehyd, even in comparatively weak solutions, destroys the activity of tetanus toxin. Specific Prophylaxis. — Tetanus antitoxin is a specific and trustworthy preventive. Its use, however, must be understood to achieve satisfactory results. The antitoxin must be administered before the advent of symptoms, for after the tetanus toxin has combined with the motor nerve cells in the central nervous system it can neither be displaced nor neutralized with antitoxin. In such cases the most that the antitoxin can do is to combine wi4:h and neutralize the free toxin and thus pre- vent further damage. This in itself is quite worth while in the treat- ment of tetanus. At least 1,500 units of tetanus antitoxin should be given as a prophylactic dose.^ It is important to remember that the ^As soon as symptoms appear 20,000 units or more of tetanus antitoxin should be introduced directly into the circulation by intravenous injection; some antitoxin may also be injected into the nerves leading from the wound. Nicoll has obtained favorable results with antitoxin, even after symptoms have devel- oped, by injecting 3 to 5,000 units into the spinal canal, 10,000 units intra- 82 DISEASES HAVING SPECIAL PEOPHYLAXIS tetanus antitoxin is eliminated or otherwise disposed of in the hody jn the eonrse of 10 days or 2 weeks. Therefore, in eases in which fh(! wound does not heal well, as a result of mixed infection, or for otix r reasons, it is desirable to repeat the injection. This may be done at intervals as long as the danger persists. Occasionally tetanus bacilli persist in the pus-infected tissues, and, when the injected antitoxin has been exhausted, there may occur a late development of tetanus, liowan ^ reports a fatal case of tetanus in spite of the prophylactic use of 2,000 units of antitetanic serum, given 5 hours after the accident. In this case, however, the symptoms appeared 25 days later. The wound in this case was a compound fracture with a free discharge of rather foul-smelling pus. Instances in which 1,500 units of tetanus antitoxin have failed to prevent the development of tetanus in this country are rare. The few failures in France and Germany may be attributed to the fact that in those countries it is customary to use a smaller amount or a less potent serum than is used in this country. Wounds produced by blank cartridges and other Fourth of July accidents should always be regarded as suspicious, and should be given careful local treatment, supplemented with a prophylactic injection of antitoxin. The prevention of tetanus complication of vaccine wounds consists in : 1. The use of a reliable vaccine which has been biologically tested in accordance with the federal act. 2. Proper methods of vaccination to avoid unnecessary scabs and anaerobic wound conditions. 3. Surgical asepsis of the operation and after-treatment. Tetanus and other wound infections may be avoided, in those ex- posed to accidents, by cleanliness of body and clothing. A bath before a battle is a reasonable protection said to be adopted in the Japanese Army and Navy. The common experience of mankind teaches that most wounds heal without tetanus, and that tetanus is, in fact, a rela- tively rare infection. The physician, however, is in no case justified in taking chances, and it is one of the duties of the medical profes- sion to teach the public that it pays to thoroughly cleanse and care for wounds, however trivial, at once, and in accordance with modern methods. venously, and 10,000 units subcutaneously. (Jour. A. M. A., LXIV, 24, June 12, 1915, p. 1982.) In tetanus, as in diphtheria, time is the important element. A few units introduced early are wortli more than thousands late. Vow. A. M. A., XIV, No. 7, Feb. 12, 1910, p. 533. CHAPTER II DISEASES SPREAD LARGELY THROUGH THE ALVINE DISCHARGES TYPHOID FEVER Typhoid fever is a sanitary problem of first magnitude, especially in this country, where it is unduly prevalent. In the United States typhoid fever stands fourth on the list of mortality tables: tuberculosis comes first, then pneumonia, cancer, and typhoid fever. The aver- age fatality from typhoid fever being nearly 10 per cent., it would, therefore, take still higher rank on the morbidity tables. In 1910 there were 25,000 deaths from typhoid fever in the United States, representing at least 250,000 cases — one jjerson in every 400. Our general attitude toward typhoid fever is inconsistent; familiar- ity has bred a remarkable indifference to the disease. Every case of typhoid fever means a short circuit between the alvine discharges of one person and the mouth of another. The physician has a dual duty in the care of a case of typhoid fever: one is to assist the patient, the other is to protect the community. On the other hand, the people should learn the lesson that a case of typhoid fever should be regarded as seriously as a case of cholera. These two diseases present many features in common. Both are intestinal infections of bacterial na- ture; in both diseases the alvine discharges contain the microorgan- isms which reinfect another person when taken by the mouth. Both diseases prevail especially in hot weather, both diseases are peculiar to man, so that the patient is the fountainhead of each infection. Water, food, fingers, and flies play a similar role in both instances. In the case of cholera the dread of the disease is an important factor in keeping it out of the country or in preventing its spread when once introduced. By strange, contrast, there is a remarkable indifference to typhoid fever. A wholesome fear of typhoid fever would materially assist the health authorities in combating what may be considered one of the major sanitary problems of the age. From the standpoint of preventive medicine, it is proper to regard an outbreak of typhoid fever as a reproach to the sanitation and civilization of the community in which it was contracted. When the matter is better understood health authorities will be held responsible for this and other preventable infec- 83 84 DISEASES HAVING SPECIAL PEOPHYLAXIS tioiis, just as soiiK' one is now held responsible for preventable accidents.^ Much liarin has been done by insistin<^ that typhoid fever is in- fectious, but not contagious; it is both — that is, communicable.^ Typhoid fever occurs both in endemic and epidemic forms. It may truly be regarded as pandemic. Normally, typhoid fever is a warm weather disease. It recurs as an annual crop from July to Octo- ber.^ Epidemics caused by infected water occur especially in the early spring, late fall, or winter months. Milk outbreaks may occur at any time of the year. Autumnal typhoid in our cities is due partly to infection contracted at health resorts, and has, therefore, been called a vacation disease. Typhoid fever is more prevalent in rural districts than in cities. In the United States there is more typhoid fever in the southern states than in the northern zone. The only explanation to account for this is the influence of temperature, rural conditions, and asso- ciation with the negro. Typhoid fever is no respecter of rich or poor; it attacks those in robust health, all ages, both sexes. Typhoid fever is a disease which ordinarily attacks the individual during the period of greatest economic value to the community. The economic loss, therefore, is appalling, and has been estimated to reach the sum of no less than $100,000,000 annually in the United States. Again, typhoid fever is an infection against which the individual alone cannot protect himself wholly without the aid of the community. Prevalence. — Typhoid fever prevails more or less in all countries — the amount of the disease, however, varies greatly. It appears to be a disease of defective civilization, for those communities paying least attention to sanitation, as a rule, suffer most. In the United States there are comparatively few communities of 1,000 inhabitants or more which, during any period of twelve consecutive months within the last decade, have been entirely free from typhoid fever. According to the United States census report for 1900, the average typhoid death-rate in the United States was 46.5 per 100,000 inhabitants. In 1908 the death toll from typhoid fever was no less than 35,000 in the United States. In other words, one person in about 200 in the United States contracted typhoid fever that year. It is estimated that in 1910-11 the number of deaths was reduced to about 25,000. The seriousness of these figures may be judged by estimating the probable number of cases of typhoid fever among persons handling the milk supply. Take, for instance, a city, as Washington, receiving its milk from a thousand dairy farms. On the average there will be about four persons on each farm who in one way or another come in contact with the milk. That makes 4,000 persons among whom about 20 cases of typhoid ^ See Vennen vs. New Dells Lumbar Co., page 1046. ^ For distinction between these terms see page .366. ^In tlie southern hemisphere tlie typhoid season is during our winter. TYPHOID FEVER 85 may be expected to occur annually. Add to this the carriers and it is no wonder that milk-borne outbreaks of tyjjhoid fever are common occur- rences. The rate of prevalence of typhoid fever in the United States in comparison with the rates of many other countries is very high. Thus, the annual death-rate from typhoid fever per 100,000 population for the period 1901-1905 was: in Scotland, 6.2; in Germany, 7.6; in England and Wales, 11.2; in Belgium, 16.8; in Austria (1901-1904), 19.9; in Hungary, 28.3 ; in Italy, 35.2 ; while the rate in the United States during the same period was about 4:6.5. A great improvement in the typhoid situation is now taking place in this country — and many states and cities are reporting figures approaching the European rates. A comparison between the prevalence of typhoid fever in this country and abroad is impressive. The following ten European cities with a total population of about 15,000,000 have an average typhoid rate of 2.4 per 100,000 during the 10 years 1901-10 1^ ANNUAL DEATH-RATES FROM TYPHOID FEVER PER 100,000 POPULATION IN 10 EUROPEAN CITIES Average Average . for 10 years, for 5 years, 1906 1907 1908 1909 1901-lClO 1901-1905 1.7 3 2 2 1 5 2.4 3 4 2 2 1.7 2.5 4 2 3 3 1.9 2.9 8 3 3 2 1.2 3.7 4 5 3 4 2.8 3.7 4 4 3 4 3.3 3.8 4 4 4 4 4.2 4.2 4 7 2 6 4.2 4.5 8 4 2 7 2.7 4.7 8 6 4 5 2.2 Stockholm . Christiania . Munich .... Edinburgh . Vienna .... Hamburg . . BerUn Dresden . . . Copenhagen London .... 1.8 1.6 1.4 .3 3.8 4.1 2.9 2.2 3.6 3.3 The following fifteen European cities with a population of about 9,000,000 had a typhoid death-rate of 5.3 per 100,000 in 1909 and only 4.5 in 1910 : ^ These facts and tlie following instructive tables are taken from : "The Necessity of a Safe Water Supply in the Control of Typhoid Fever," by Allan J. McLaughlin, U. 8. Pub. Health Reports, XXVII, 12, March 22, 1912. 8G DISEASES SPREAD TIIKOUCH Al.VIXE DISCHARGES ANNUAL DEATH-RATES FROM TYPHOID FEVER PER lOO.fKX} POPUI A'l'IOX IN lOOTJIER EUROPEAN CITIES Citv Frankfort Antwerp Bristol Nuremberg Birmingham Belfast Lyon Leeds Lii'erpool Sheffield Rotterdam Amsterdam Paris Bradford Leipzig Total average rate l.o 0.0 1.0 2.3 2.8 2.1 2.6 5.1) 3.9 5.2 3.9 5.8 4.4 7.2 3.8 8.4 3.9 9.4 3.0 6.4 6.5 3.8 6.7 8.4 5.6 4.3 9.2 8.3 7.5 4.5 The following eight European cities with a total i^opulation of 7,500,000 had a typhoid death-rate of 13.9 in 1909 and 15.6 in 1910. These rates would have been considered low in America before 1910, but the European officials consider the persistence of such rates to be a reflection : ANNUAL DEATH-RATES FROM TYPHOID FEVER PER 100,000 POPULATION IN 8 OTHER EUROPEAN CITIES City 1909 1910 Glasgow Budapest Brussels Dublin Manchester Moscow Warsaw Petrograd Total average 12.5 6.4 9.4 13.6 7.4 16.1 15.7 12.2 13.9 10.3 13.8 15.0 13.5 17.4 25.2 33.7 To recapitulate, in northern Europe the 33 principal cities, with an aggregate population of 31,500,000, had an average typhoid death- rate per 100,000 population of 6.5 in 1909 and 1910. This includes such a notorious typhoid center as Petrograd, which had a rate of TYPHOID FEVER 87 33.7 in 1910. The high rate in Petrograd is considered to be due to the water supply, which is partly filtered and partly raw Neva water. Let us now compare these rates with typhoid fever in America : Annual Death Rates from Typhoid Fever per 100,000 Population in 50 Cities OP the United States Having More than 100,000 Inhabitants City 1909 1910 1911 1912 1913 1914 1915 Birmingham, Ala 59.7 16.1 11.2 13.9 24.1 9.0 20.5 34.3 50.6 12.6 22.0 45.3 28.4 24.9 13.8 7.7 21.3 10.5 8.4 20.5 17.2 21.0 18.9 29.3 16.2 36.8 8.8 11.9 9.7 19.0 23.8 12.1 9.4 11.2 13.3 13.3 19.6 26.9 41.7 22.0 22.3 24.6 16.4 11.4 48.8 52.0 24.1 23.8 43.2 21.4 49.5 14.2 16.5 15.5 27.5 4.9 17.9 23.2 50.1 13.7 28.5 31.7 31.5 42.0 11.3 9.5 15.0 19.7 15.7 23.0 28.3 58.7 19.5 54.4 14.9 86.7 11.5 13.1 7.1 14.0 20.4 11.6 13.7 28.2 8.8 17.9 18.1 21.4 37.2 22.4 17.5 27.8 16.9 17.9 27.4 48.9 21.9 14.2 45.4 45.7 45.5 11.6 14.0 15.3 18.0 3.8 24.9 22.2 66.1 10.9 25.8 23.7 31.0 27.6 8.7 2.8 14.7 7.3 6.0 15.8 26.7 11.9 10.5 29.9 16.1 18.1 7.2 10.5 7.0 18.8 25.0 10.9 10.6 16.2 11.4 14.2 13.9 18.6 23.1 19.1 14.6 25.6 14.3 12.1 65.4 53.9 17.8 10.3 35.6 19.0 37.3 15.0 13.7 13.6 15.2 8.3 24.4 23.0 41.9 7.4 17.8 21.8 14.0 24.6 8.0 3.7 18.0 10.1 3.3 17.5 33.9 11.7 10.6 12.0 10.7 14.0 7.8 8.1 5.4 17.7 11.8 9.6 11.7 16.7 7.7 6.9 19.6 19.1 31.7 16.6 12.8 13.1 10.3 10.2 58.9 32.8 16.7 7.6 17.4 25.7 36.0 12.1 12.0 16.1 13.5 6.2 12.7 16.4 21.9 10.4 24.4 23.2 16.9 23.8 8.2 9.2 8.9 10.0 5.8 29.4 18.2 12.0 9.1 21.9 16.9 7.6 10.8 8.7 8.3 27.4 15.4 7.0 8.9 13.0 6.8 14.1 19.1 18.0 41.6 6.5 15.7 19.5 9.4 11.2 34.2 36.9 20.3 4.7 7.0 11.3 39.7 7.7 6.6 12.7 9.0 3.5 15.2 11.9 46.3 6.6 25.8 25.9 21.9 22.6 9.0 1.8 9.6 10.8 3.8 14.1 27.6 12.5 11.0 16.3 12.0 4.5 7.5 7.5 4.5 17.5 16.3 6.3 10.2 10.0 6.2 8.1 13.2 11.3 36.9 6.9 7.6 15.0 9.2 11.0 42.6 51.3 14.8 7.0 12.5 8.1 33.7 Los Angeles, Cal 5 5 Oakland, Cal 6.7 San Francisco, Cal Denver, Colo 9 4 6.6 Bridgeport, Conn New Haven, Conn Washington, D. C Atlanta, Ga 5.1 18.3 11.7 11.1 Chicago 111 5.4 Indianapolis, Ind Louisville, Ky 12.3 12.0 New Orleans, La 21.5 Baltimore, Md 21.9 Boston, Mass 5.5 Cambridge, Mass Fall River, Mass 1.8 11.8 Lowell, Mass 16.0 Worcester, Mass 5.6 Detroit, Mich 12.8 Grand Rapids, Mich Minneapolis, Minn St. Paul, Minn 24.6 7.1 7.4 Kansas City, Mo St. Louis, Mo 7.2 7.0 Omaha, Nebr 3.7 Jersey City, N. J Newark, N. J 5.6 2.5 Paterson, N. J 5.1 Albany, N. Y 12.6 Buffalo, N. Y 9.9 New York, N. Y Rochester, N. Y 6.0 6 Syracuse, N. Y 5.9 Cincinnati, Ohio Cleveland, Ohio 7.8 7.8 Columbus, Ohio 13.3 Dayton, Ohio 13.6 Toledo, Ohio 23.9 Portland, Oregon Philadelphia, Penn Pittsburgh, Penn Scranton, Penn 5.2 6.6 24.7 10.4 Providence, R.I Memphis, Tenn 8.4 24.6 Nashville, Tenn 35.1 Richmond, Va 12.7 Seattle, Wash 2.5 Spokane, Wash 10.7 Milwaukee, Wis 4.5 OfBcial figures kindly furnished by Richard C. Lappin, Chief Statistician Division of Vital Statis- tics, Bureau of the Census, U. S. Dept. of Commerce. Data for 191o from J. A. M. A. April 22, 1916, p. 1305. 88 DTSEASl^LS SPRKAD ^rJlUOUGlI ALVIXE DiSOHAKGES These 50 registration cities in the United States have an aggregate population of over 20,000,000. The average typhoid death-rate in these cities for 1910 was 25 per 100,000 irdiabitants. Unit of comparison Aggregate population Deaths per 100,000 from typhoid fever, 1910 33 principal European cities in Russia, Sweden, Norway, Austria- Hungary, Germany, Denmark, France, Belgium, Holland, 31,500,000 20,250,000 6.5 25.0 18.5 The excess of 18 deaths per 100,000 in the nrban population alone shows that we have had, in the 50 cities mentioned above, at least 3,600 deaths, and probably 36,000 cases of typhoid fever, which were pre- ventable and should never have occurred. For the whole United States the number of cases for each year readily preventable by methods within our grasp would probably reach 175.000, and the deaths so avoided would total about 16,000. In 1909 there were more cases of typhoid fever in the United States than there were cases of plague in India, in spite of the fact that India's population is two and one-half times that of the United States. The typhoid rates in our larger cities are coming down, owing to im- proved water supplies and better sanitary conditions. In 1912, more than half the cities in this country with over 100,000 population had typhoid rates under 13.9. In fact the improvement in our typhoid situ- ation is one of the great sanitary reforms now going on. Residual or "Normal" Typhoid. — When a city such as Albany, Chicago, Lawrence, Lowell, or Pittsburgh, which has been using grossly polluted water, is furnished with a water supply of good sanitary quality, there at once results a marked reduction in the amount of typhoid fever. The curve is not only lowered, but it is also changed in character. The remaining typhoid after the water-borne infec- tion has been removed is known as residual typhoid, and the curve in such cases is spoken of as the "normal" typhoid curve. The normal curve shows a distinct summer prevalence recurring with marked regularity each year, and lacks the great irregularities which characterize the curve of a community drinking badly infected water. Normal typhoid is endemic typhoid; Sedgwick has proposed the name "prosodemic" {proso, through, and demos, the people) as more expres- sive of this type of the disease. The amount of residual typhoid varies TYPHOID FEVEE 89 markedly in different localities; thus it is twice as high in the southern as in the northern part of our country ; it is much greater here than in most parts of Europe. Channels of Entrance and Exit. — The typhoid bacillus probably al- ways enters by the mouth. Typhoid fever is generally regarded as primarily a gastro-intestinal infection, although the disease itself is not produced unless the blood, glands, and other structures of the body are invaded with the specific microorganism. The typhoid bacil- lus grows and multiplies in the intestinal tract, penetrates the mu- cosa, and thus invades the body. The bacillus leaves the body mainly in the feces and urine, occasionally in the sputum and other discharges. Typhoid bacilli appear in the feces early in the disease; sometimes be- fore the fever. Later in the disease they diminish in niimber and usually disappear during convalescence, although they may continue in- definitely (see "Bacillus Carriers," page 92). The feces may contain only a few typhoid bacilli; usually they are present in considerable numbers; occasionally they occur almost in pure culture, practically replacing the colon bacillus. Typhoid bacilli commonly appear in the urine about the second, third, or fourth week. They grow well in this fluid both within and without the body, and may be present in such enormous numbers that the urine resembles a 24-hour-old bouillon culture. From the stand- point of prevention, it is very important not to neglect the virus in the urine. Urotropin (hexamethylenamin) in ten-grain doses or more three times a day diminishes the frequency of typhoid bacilluria, and is also effective in curing this condition when once established. The sputum ordinarily does not contain the bacilli unless there is a pneumonia or severe bronchitis. Gould and Quales, and also Purjesz and Perl,^ have recently found typhoid bacilli in about 50 per cent, of the cases by rubbing the gums, tonsils, and tongue of patients suffer- ing with typhoid fever. These microorganisms from the mouth were found as late as the fourth to eighth week of convalescence. These findings are important both from the standpoint of diagnosis and epidemiology. The bacilli may be eliminated with the discharges from abscesses, such as periostitis, months and even years after the disease. Diagnosis. — An early diagnosis of typhoid fever is important not only for the successful treatment of the patient, but is of vital impor- tance in controlling the spread of the infection. The early diagnosis can only be assured through laboratory methods. Typhoid bacilli may be isolated either from the blood or the feces. Blood Cultures. — Probably the easiest method, as well as the one giving the maximum information, is through blood ciiltures. The tak- ing of a little blood for this purpose is no more difficult or annoying "■Wien. klin. Woch., 1912, XXV, 1494. 90 DISEASES SPREAD THROUGH ALVINE DISCHARGES to ilio ]);ili('nt tluui ,swal)l)ij),i( ilu; tlir(jai for (li|)htheria. A few drops of blood may he, ohlaiiu'd by pujicturiiig Ibc lobe of the ear or the finger, with the usual preeautions to prevent bacteiial contamination, A much better method, however, consists in withdrawing 5 to 10 c. c. of blood by means of a syringe from one of the veins at the bend of the elbow. The technic is very simple, and, if the needle is sharp, the patient scarcely feels the puncture. In fact, if the attention of the patient is distracted a skillful oj)erator can withdraw 10 c. c. of blood in this way before the patient is aware that anything has been done. The blood may be planted in bouillon, or, better, in bile. After 24 hours in the incubator, any growth that occurs is transplanted to other media, a pure culture obtained, and tested, for agglutination. Often a pure culture is obtained in the first medium, so that the diag- nosis may be established in 34 hours — at most, 2 or 3 days. Typhoid bacilli appear in the blood early in the disease, perhaps occasionally during the prodromal symptoms. Kayser obtained posi- tive results from 90 per cent, in the first week, C5 per cent, in the second, 42 per cent, in the third, 35 per cent, in the fourth. Our results in Washington were approximately the same. The typhoid, bacilli probably do not grow in the blood during life. Their presence in the blood stream represents an overflow from the spleen and lym- phatic tissues. The presence of typhoid bacilli in the blood may be taken to mean typhoid fever. The same cannot always be said if found in the feces or urine. The Feces. — From the feces or urine typhoid bacilli are best isolated upon Endo's medium. This consists of a 4 per cent, alkaline agar containing fuchsin, wdiich has been decolorized with sodium sul- phite. Upon the surface of this medium typhoid colonies appear in 24 hours as translucent, dewdrop-like colonies, wdiereas colon bacilli and other organisms that produce acid and split the fuchsin appear as red colonies. Suspicious colonies are fished and may be tested at once under the microscope for agglutination, or may be planted in bouillon to obtain a growth sufficient for macroscopic agglutination tests. In any critical case pure cultures should be obtained and studied for morphological, cultural, and other biological characters. A modi- fied Endo's medium and a rapid technic for diagnostic purposes, de- scribed by Kendall and used with success in my laboratory, are sum- marized as follows: Technic. — Make plain, nutrient, sugar-free agar as follows : Tap water (cold), one thousand cubic centimeters; powdered agar, fifteen grams; peptone (Witte), ten grams; meat extract (Liebig), three grams. Cook in double boiler one hour. Make the reaction just al- kaline to litmus by the cautious addition of NaOH. Cook fifteen minutes to set the reaction, and then filter through absorbent cotton. TYPHOID FEVEE 91 The tap water should be as cold as possible and the agar should be "dusted" on the surface and allowed to settle into the medium before heat is applied and before the other ingredients are added. After filtration, the medium is stored in flasks containing known amounts, conveniently in one hundred-cubie-centi meter lots, and steril- ized in the autoclave. To use the medium: (a) Prepare a ten per cent, solution of fuch- sin in ninety-six per cent, alcohol, (b) Prepare a ten jier cent, solu- tion of sodium sulphite in water. Add one cubic centimeter of (a) to ten cubic centimeters of (b) and heat in the Arnold sterilizer for twenty minutes = (c). Add one per cent, of lactose (which must be chemically pure) to the agar medium described above, and heat in the Arnold sterilizer until the medium is melted and the lactose thoroughly distributed in it. The decolorized fuchsin solution (c) is then added in the pro- portion of one cubic centimeter of the mixture to each one hundred cubic centimeters of medium; then thoroughly mixed. Plates are then poured and allowed to harden (with the covers removed) in the incubator for thirty minutes, after which time they are ready for inoculation. Preparation of Feces for Inoculation. — The feces are collected pref- erably in the small rectal tubes described by Kendall.^ A small por- tion of feces (about a loopful) is thoroughly emulsified in ten cubic centimeters of sugar-free broth, and preferably incubated one hour at 37° C prior to the inoculation of the plates. This preliminary in- cubation does two things : the clumps of bacteria settle down, leaving a more uniform suspension of bacteria in the supernatant fluid for inoculation, and the bacteria undergo a slight development in a medium particularly suited for their growth. The thin suspension of the stool is now rubbed upon the surface of the agar plates by means of a bent, sterile, glass rod, and the plates incubated for 18 hours at 37° C. The suspicious translucent, colorless colonies are removed entire to small test-tubes containing one cubic centimeter of broth and incubated for two hours at 37° C. At the end of this time there will be sufficient growth to make the customary microscopic agglutination tests. Con- firmatory cultural characters may be obtained by inoculating suitable media from the same tubes as those from which the organisms for agglutination were obtained. Physicians should encourage boards of health to furnish diagnostic aids of a laboratory nature. Such work should be in the hands of specialists rather than entrusted to those who make occasional anal- yses. Early and accurate diagnosis is just as important to prevent the "■Boston Med. and ^urg. Jour., CLXIV, No. 1, Sept., 1911. 92 DISEASES SPlfEAD TlIIfOUrilL ALVIXE JMSCIIARCES spread, of other coinmuiiieable diseases as it is with typhoid. These facts emphasized here will not be repeated under each disease. Bacillus Carriers. — About 2 to 4 per cent, of all cases of typhoid fever the patient continues to shed typhoid bacilli in tlie urine or feces during and after convalescence. Some persons shed typhoid bacilli without a clinical history of having had the disease. We therefore recognize three kinds of carriers : acute, chronic, and. temporary. An acute typhoid bacillus carrier continues to discharge the infection not longer than 6 weeks following convalescence. A chronic carrier con- tinues to discharge the bacilli 6 weeks longer. A temporary carrier is a person who has not had clinical typhoid fever but who discharges typhoid bacilli for a short period. Albert states that 25 per cent, of all chronic typhoid carriers have never had typhoid fever; and further estimates that one in every 1,000 of the general population is a carrier. While it would seem that typhoid bacilluria should be especially dangerous, a study of the cases indicates that most of the outbreaks that have been traced have been due to carriers who discharge the organisms in their feces rather than in the urine. It seems that some typhoid carriers are more dangerous than others. More cases are traced to women ^ than to men. This is probably owing to the fact that the chief danger lies in handling foodstuffs, so that a carrier occu- pied as a cook or waitress, or on a dairy, is a special menace. Sawyer ^ reports a very instructive history of a typhoid carrier (H. 0.) responsible for several outbreaks. The carrier was carefully studied over a period of several years, during which time he infected thirty persons, five of whom died. Frequent examinations of feces of this carrier gave negative results for four months after he had been treated with autogenous typhoid vaccines ; nevertheless, he infected three persons when subsequently released from quarantine on parole. The removal of the gall-bladder failed to cure H. 0., for typhoid bacilli were found in the feces several times after the operation. It is particu- larly noteworthy that 41 successive examinations of feces during a period of fourteen months all proved negative, yet the typhoid bacillus was finally isolated from the stomach contents containing bile. This carrier, on account of the virulence of the organism, or careless per- sonal habits, is unusually dangerous and represents a class that should be controlled by quarantine or close supervision. . Another instructive outbreak caused by a carrier is reported by Sawyer ^ in which 93 cases of typhoid fever occurred in Hanford, Cal., as a result of infected food served at a public dinner. The vehicle of infection was a large pan of spaghetti prepared by a carrier. This dish ^ Women are more subject to t;all-stones. ^Jour. A. M. A., June 19, lOir/, LXIV, 25, p. 2051. '■Jour. A. M. A., Oct. 31, 1914, LXlll, IS, p. 15;J7. TYPHOID FEYEE 93 was baked after it had been infected, but this baking was shown by laboratory experiments to have incubated tlie bacteria instead of dis- infecting tlie food. The Widal reaction is almost constantly present in the blood of typhoid bacillus carriers. It is, therefore, of distinct value as a pre- liminary test in the epidemiological search for carriers. In blood test- ing for this purpose dilutions of 1 :50 and 1 :25, and even a titer of 1 :10, may be used. The test should be made with both B. typhosus and B. paratyphosus. The bacilli should then be searched for in the urine and feces of those giving a positive reaction. It should be remembered that about 90 per cent, of persons immunized with typhoid vaccine will give a positive reaction. The question of preventing the spread of the disease through bacil- lus carriers is important and ditficult. Surgical methods fail to cure carriers, for the typhoid bacillus may continue to grow in other parts of the intestinal tract than the gall bladder. Medical measures, such as urotropin, are efficient for bacilluria, but are of no avail in the fecal carriers. Attempts have been made to relieve the condition by the use of bacterial vaccines. Petfuschky ^ and also Header have reported en- couraging results, especially with the use of autogenous cultures. Hek- torn suggests the use of kaolin, which acts by adsorption. So far certain cases resist all attempts to relieve the condition. It is unnecessary to place bacillus carriers incommunicado. It is sufficient to restrict their activities so that they cannot infect food or their surroundings. With proper care and cleanliness typhoid carriers may present little danger to their fellow men. The problem, at present, is to detect the carriers, so as to establish a sanitary isolation, if not an actual quarantine." Resistance of the Virus. — The typhoid bacillus has no spore. It is, therefore, comparatively easy to destroy. The only difficulty present- ing itself is getting at the bacillus Avhen imbedded in fecal masses. When dry, most typhoid bacilli die in a few hours; occasionally a few survive for months. The fact that typhoid bacilli are killed by drying renders infection through dust unlikely. When a moist medium, such as water, milk, or urine, is heated to 60° C, practically all the typhoid bacilli such a medium may contain are killed. An exposure at 60° C. for 20 minutes will surely kill all of these microorganisms. They are not destroyed by freezing (see "Eelation to Ice," pages 948 et seq.). In their resistance to germicides typhoid bacilli behave like the average non-spore-bearing bacilli. Thus bichlorid of mercury, 1-1,000; phenol, 21/2 per cent. ; formalin, 10 per cent., are effective upon the ^Deut. med. Wochschr., July 11, 1912, XXXVIII, 28. ^ The facts covering the infectivitv of carriers are summed up hj Ledinghamj 39th An. Report Local Gov. Board, 1909-10, Supplement, p. 249. !)4 DISEASES SPliKAI) T\\\{i)\jilll ALVINE DISCHARGES naked germs. In order to kill the typhoid bacilli in feces special pre- cautions or stronger solutions are necessary (see pages 10!) and 1171). The viability of typhoid bacilli in feces is very variable, depending on the compositioiT of the feces and the varieties of other bacteria present. Sometimes the ty})hoid bacilli in feces ])crisb in a few hours, usually in a day; under exceptional circumstances they may live for much longer periods. In the Plymouth epidemic typhoid bacilli prob- ably remained alive and virulent in the feces, exposed to the winter's cold, for several months. Levy and Kayser found they remaijied alive in feces for 5 months in the winter. The life of the organism in privies and in water is usually comparatively short. In nature they die, as a rule, in water in about 7 days and often after 48 hours. They probably live longer in clean water than in contaminated water. In the outer world antibiosis plays an important part, also the presence of deleterious chemicals, temperature, light, desiccation, dryness, and other factors known to be injurious to spore-free bacteria. As a rule, the typhoid bacillus does not survive long in the soil under the usual conditions. Typhoid Bacillus in Nature.-^The typhoid bacillus should be re- garded as a pathogen, not as a saprophyte. It lives and grows prin- cipally in the human body. It has a tendency to die in water, air, soil, upon fomites, or in nature generally. The grand exception to this statement is in the case of milk, in which the typhoid bacillus grows well. The typhoid bacillus may live 13 days in crude sewage (Firth) ; 14 days in a septic tank (Pickard) ; 4 months in butter (Bailey and Field) ; 5 days in home-made cheese (Heim) ; 12 days in pot cheese (Lemke) ; 39 days in ice cream (Mitchell). It is destroyed in 24 hours in milk, butter-milk, whey or butter having an acidity of 0.3 to 0.4 per cent. In endemic centers the typhoid bacillus is much more widely dis- tributed in man than the cases indicate. Thus, in the District of Columbia, of 1,000 healthy persons examined during the typhoid season of 1908, typhoid bacilli were found in the feces in 3 instances. At least one and perhaps two of these individuals were regarded as temporary carriers. In each instance the organisms were found only once. The population of the District of Columbia in 1908 was 300,000, and at the ratio of 1 per 1,000 this would represent about 300 healthy persons in that community harboring and shedding typhoid bacilli for a brief period of time during the typhoid season. Modes of Spread. — Typhoid fever is spread either by direct or in- direct contact — indirectly through water, milk, and other foods ; through "contacts"; and also flies, fingers, and fomites. Each of these modes of spread needs separate consideration. Water. — Water-borne typhoid is a common occurrence. Not long TYPHOID FEVER: 1902 TO 1916 Death Rate per 100,000 of Population SouHi33(n6,ln6. SanAnfonio.Taos 5fli;annali.6a. MewOrkans.La. Covington .Xy. Riciimond.Ua. LouisuiUe.Ky. AHanlrfl.Ga. 5«af tie. Wash. EuansuiUe.lni. SpringficU.lU. Granbftapifts.Wich. li)Uminaron,DcL lancasfer.Pa. HQTri5t»urj,Pa. Uttetlmfl.tf.Uo, fiinneapous.Minn. ToU^ O.Ohio Cincinnati, Ohio PhUa6clphia,Pa. AUcgricnK,Pa. PittsbuM va.. ciTy Richmond boToujh.iK.M. 2u«ns(x)rouflh,flr.Sf. cam6en.3f.J. lowdinass. Unco[n,KtbT. Dayton. Ohio Memphis. TtttB. wexuton.rtass. HochcstcrA'.y. Suracuse.af.y. Tall Riuer, \ r S 17 r /Zo V \ J f » ItO v ^1 i J f 1 i S » 100 n 1 § ^ 1 90 $ 1 fc 1 St 3 H ^ go ^ 1 C i fo 1^ 5 r ^ ^ 1 to K 1 ^ ^ go j *o \ ^0 > I ?« V ^ /o ^ Fig. 13. — Immediate and Striking Effect of Purifying a Badly Infected Water Supply upon the Typhoid Situation. water-borne and must have taken place when the water was very cold. In fact, as previously pointed out, extensive water-borne epidemics of typhoid fever rarely occur in the summer time. The epidemiology of water-borne typhoid caused by distant, diluted and attenuated infection is not understood. It was formerly thought that a high typhoid rate necessarily meant badly infected water. We know now that this does not necessarily follow, as has been proven by the experiences in Washington, Winnipeg, army camps, and many southern cities. 98 DISEASES SPREAD THEOUGIT ALVT^^p^ DISCHARGES Almost all the water-borne epidemics of typhoid fever rest up(jn cir- cumstantial evidence. It is difficult to isolate the typhoid bacillus from watei;, and the damage is usually done before suspicion points to the water.^ It is clear that in cities which have had safe water supplies for a period of years the typhoid death rate should not be above 5 per 100,000, unless some unusual conditions exist, such as poor control of milk or lack of control .over patients and carriers, and disregard of modern sani- tary knowledge. No single measure in reducing typhoid fever on a large scale ap- proaches the effect of substituting a safe for a polluted water supply. As an instance of this wholesale saving of human life, the reduction of typhoid fever in four American cities is shown in Fig. 14. Q aO 4.0 6 80 lOO 120 140 |60 IBO {100 \ 1003 H 1904. H 1905 !■■ WaUrTowa.JOr. 1906 ^ 1992 ■ 1893 r 1894 Liawrcnc<2,Miss. laOff > 1996 1998 ■ (899 r I90O AlbaiivjKr 1901 ■Ei^H I90& ^M 1908 u ^ Lhi I 1 1 CinciTmatiu Otiio. Fig. 14. -Abrupt "Reduction in Death Rates prom Typhoid Fever Incident to Water Purification in Four American Cities. Column X. -The Black Squares Indicate Raw Water and the Clear Squares Filtered Water. Ice. — Ice may, under exceptional circumstances, occasionally be the vehicle by which typhoid bacilli are transferred. Freezing does not kill B. typhosus, but there is a great quantitative reduction not only in the act of freezing, but during storage, hence the danger is greatly lessened. The most suggestive outbreak of typhoid fever attributed to ice was reported by Hutchins and Wheeler in 1903 in the St. Lawrence Hospital, three miles below Ogdensburg. A few other instances in which ice is ^ Examples of water-borne outbreaks of typhoid fever will be found in the chapter on water. TYPHOID FEVER 99 believed to have conveyed the infection have been reported, but are based upon flimsy evidence. The fact that natural ice is usually stored many weeks or months before it is used is a sanitary safeguard. Manufactured ice made from distilled water and handled with cleanly methods is above reproach. For a discussion of ice in relation to typhoid fever and other infections see page 948 et seq. Milk. — Trask collected 317 typhoid epidemics up to 1908 caused by infected milk. Since then many more instances have come to light. Doubtless many milk outbreaks have escaped attention or have been attributed to water or other sources. The typhoid bacillus grows well in milk, and it is now realized that this medium is a frequent and important mode of communication. Most milk outbreaks are reported from England or America. On account of the almost universal custom of boiling the milk in European and tropical countries, milk outbreaks are rarely reported from these regions. During the four years' study of typhoid fever in Washington, it was found that at least 10 per cent, of the cases were milk-borne. The milk usually becomes contaminated on the farm, from a case or a carrier. It may also become infected in transportation, at the city dairy, or in the home. Milk outbreaks come abruptly, rise to a peak like a water epidemic, and subside rather sharply. There are comparatively few secondary cases. Milk-borne epidemics of typhoid fever have certain characteristics which permit ready recognition. (a) There is a special incidence of the disease on the track of the implicated milk supply. The outbreak is localized to such areas. (b) The better class of houses are invaded, and persons in better cir- cumstances generally suffer most. (c) Those who drink milk are chiefly affected and those suffer most who are large consumers of raw milk. (d) The incidence is high among M^omen and children. (e) The incubation period is shortened perhaps on account of the large amount of infection taken. (f) More than one case occurs simultaneously in a house. This is a very suspicious circumstance to the epidemiologists. The first indication of a milk outbreak in a city with a good water supply is usually the fact that two or more persons in a household came down with typhoid fever within a few days of each other. (g) Clinically the disease may run a mild course, owing to the fact, no doubt, that the virus becomes attenuated in the process of multiplica- tion in the milk. In water-borne typhoid the same germs are ingested that were passed; in milk-borne typhoid it may be the succeeding gen- erations that are ingested. Milk-borne outbreaks are sometimes very extensive. One of the largest epidemics occurred in Boston (Jamaica Plain) in March and 100 DISEASES SPREAD THIIOUGU ALViXK I)IS(niAll(;KS April, 1908. Four liuiidred and ten cases were reported; ;54