i , ; ■ 
 
 f<t ■' * 
 
 NSTITUTE, BULLETIN No. 17 
 
 HX0001 5261 ? Public Health and Marine-Hospital Service 
 
 WALTER WYMAN, Surgeon-General 
 
 THE PROPHYLAXIS OF 
 YELLOW FEYEP 
 
 BY 
 
 G. M. GUITEKAS 
 
 FEBRUARY, 1 909 
 
 WASHINGTON 
 
 GOVERNMENT PRINTING OFFICE 
 
 1909 
 
 
YELLOW FEVER INSTITUTE, BULLETIN No. 17 
 
 Treasury Department, U. S. Public Health and Marine-Hospital Service 
 WALTER WYMAN, Surgeon- General 
 
 THE PROPHYLAXIS OF 
 YELLOW FEVER 
 
 BY 
 
 G. M. GUITERAS 
 
 FEBRUARY, 1909 
 
 WASHINGTON 
 
 GOVERNMENT PRINTING OFFICE 
 
 1909 
 
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YELLOW FEVER INSTITUTE 
 
 Treasury Department, Bureau of Public Health and Marine-Hospital Service. 
 WALTER WTMAN, Surgeon-General. 
 
 Bulletin No. 17. 
 
 THE PROPHYLAXIS OF YELLOW FEVER. 
 
 By G. M. Gttiteras, Surgeon, U. S. Public Health and Marine-Hospital Service. 
 
 The study of yellow fever has ever been an interesting one from 
 the time it was first observed in the Western Hemisphere to the 
 present day. 
 
 Whether the disease is indigenous to America or was introduced 
 from the west coast of Africa, is a mooted question. From the his- 
 torical data which we have on the subject it would appear as though 
 the latter opinion was the correct one. 
 
 The disease has been a scourge to the fair and fertile regions of 
 tropical and subtropical America and has greatly retarded their 
 material progress. Its existence in an endemic form at various 
 points, such as Habana, Rio de Janeiro, and Vera Cruz, has given 
 these ports an unenviable reputation with travelers and seriously 
 hampered their commercial interests, and carried from these foci 
 to other infectible territory it has caused widespread epidemics 
 resulting in great loss of life, interference with commerce, and finan- 
 cial disaster. 
 
 The peculiar characteristics of the disease and the mystery which 
 shrouded its etiology and method of propagation have invested it 
 with remarkable interest, and in our day the solution of this mys- 
 tery, in so far as the method of propagation is concerned, has given 
 us one of the most important advances in modern science. 
 
 The work of the United States Army Board in establishing beyond 
 a doubt the hypothesis enunciated by Carlos Finlay, in 1881, as to 
 the transmission of yellow fever by the mosquito, was indeed bril- 
 liant. I had the pleasure of being present at the International Sani- 
 tary Congress held in Habana when Doctor Heed presented his 
 
 (3) 
 
memorable report proclaiming the new dogma. The work therein 
 described was so thorough and the results so clearly established as to 
 leave no doubt in the minds of his hearers as to the truth of his con- 
 clusions. Considering the number of able men who had been study- 
 ing the subject, it is remarkable that a period of nearly twenty years 
 should have elapsed before Finlay's ideas were seriously considered 
 and finally accepted. It is still more remarkable when we consider 
 that since the early part of the nineteenth century various observers 
 had indicated the mosquito as in some way related to the disease 
 under consideration. There is no doubt but that the interesting work 
 of Dr. Henry R. Carter, of the Public Health and Marine- Hospital 
 Service, in establishing, in 1898, the " extrinsic " period of incubation 
 of yellow fever — that is, the interval between the infecting and sec- 
 ondary cases — gave renewed impetus to the study of the mosquito as 
 a factor in yellow fever and indirectly brought about the confirma- 
 tion of the truth of the hypothesis of Doctor Finlay. 
 
 PRINCIPLES OF PROPHYLAXIS. 
 
 The prophylaxis of 3 T ellow fever, which up to a few years ago was 
 founded on ideas so uncertain and insecure, is to-day firmly based 
 on the discovery of the transmitting agent of the disease. This agent 
 can be destroyed and may be prevented from becoming itself inocu- 
 lated and, if inoculated, from transmitting the disease to the well. 
 
 In the abstract the measures necessary to accomplish this are per- 
 fectly feasible. Xo extraordinar}^ means or intelligence is required 
 to make them effective; only a careful attention to details. But in 
 practice, when the peculiarities of human nature, the rights of the 
 individual as guaranteed by the law, and the ignorance of the people 
 have to be taken into account, the problem becomes both difficult and 
 onerous. 
 
 The subject of the prophylaxis of yellow fever has been thoroughly 
 thrashed out during the last few years, and as the matter is so simple 
 in itself there is but little that may be added to what has already 
 been said. Within the time stated the writer has been connected 
 with the two epidemics which have occurred in the United States — at 
 Laredo, Tex., in 1003, and at New Orleans and Vicksburg in the gen- 
 eral epidemic of 1005 — and has carried out with success the principles 
 of prophylaxis which will be referred to in this article. It is not. 
 however, the purpose to enter herein into the minutiae of the meth- 
 ods of prophylaxis, but rather to invite attention to some of the 
 difficulties to be encountered and to suggest some of the means 
 whereby, in the opinion of the writer, the obstacles found in the 
 practical application of the principles involved may be lessened or 
 eliminated. 
 
IMPORTANCE OF EARLY DIAGNOSIS. 
 
 The knowledge that we now have of the transmission of yellow 
 fever gives us a secure basis upon which to lay our plans against the 
 introduction of the disease or to prevent its spread when introduced. 
 There is, however, one link wanting to give us absolute control of the 
 disease, and that is the etiological factor. The consensus of opinion 
 up to the present time is that it is a micro-organism, ultramicroscopic, 
 and as yet beyond our means of detection. The importance of deter- 
 mining this causative agent is apparent from every point of view, but 
 especially so as an aid to diagnosis, for the prompt and positive diag- 
 nosis of yellow fever is one of the most important factors in the pro- 
 phylaxis of the disease, especially when it appears in a locality where 
 it was previously unknown or that has been free of it for some time. 
 
 In order to take measures against the spread of a disease it is first 
 of all necessary that we should be aware of its presence. In the case 
 of yellow fever considerable embarrassment presents itself in deter- 
 mining this fact, both on account of the inherent difficulty in making 
 the diagnosis and the natural fear of the attending physician of the 
 alarm and other unfortunate consequences which will usually follow 
 a declaration of its presence, and especially the fear that he may be, 
 after all, mistaken in the diagnosis. This applies particularly to 
 those localities where yellow fever is a new or an infrequent visitor 
 and where there exists an unreasonable fear of the disease. 
 
 It is foreign to the purpose of this paper to enter into a discussion 
 of the differential diagnosis of yellow fever, but I desire to impress 
 upon the reader, the importance, from a prophylactic point of view, 
 of the early diagnosis of all cases of this disease. We know that the 
 Stegomyia calopus can only become infected by biting the patient 
 during the first three days of the illness ; hence the diagnosis should 
 be made in its very incipiency. Frequently it is not easy to do this, 
 especially in mild cases. It is here that our knowledge is at fault and 
 all our energies should be bent to discover some means of making a 
 positive diagnosis, one which can not be controverted. When this is 
 achieved the citadel will have been won and the last vestige of 
 danger from this disease removed. 
 
 USUAL CONDITIONS WHEN YELLOW" FEVER IS DEOLAEED. 
 
 Under present circumstances the following conditions almost inva- 
 riably confront us in an outbreak of yellow fever in a locality usually 
 free from it, such as, for instance, our South Atlantic and Gulf 
 coast: A case of fever presents itself to a physician who is not on 
 the lookout for yellow fever and who perhaps has never seen the 
 disease. If it be a mild case of }^ellow fever, it will probably get 
 well without his suspicions being even aroused. If, however, it be 
 
of moderate severity and the physician careful and observant, he will 
 soon note symptoms which do not square with the fevers which he has 
 been accustomed to see. He may then suspect that all is not right 
 and begin to think of the possibility of yellow fever. Immediately 
 the purely medical and scientific character of the case becomes 
 clouded by the material considerations involved. Is the diagnosis 
 positive? Shall the case be reported or not? From where could 
 the infection have come? This last question is always given undue 
 weight, with fatal results, because as a rule it is impossible to answer, 
 and its consideration leads to uncertainty and delay. But why 
 should we pause to answer? Do we do so in a case of measles, scar- 
 latina, or smallpox? Why not make the diagnosis on the symptoms 
 of the disease as presented to us and not bother at that critical mo- 
 ment with the abstruse study of its possible origin? That surely 
 would be the most rational and practical way to proceed. In any 
 case, it is indeed a heavy responsibility to satisfactorily answer these 
 questions under the conditions at present affecting our Southern 
 States or other localities similarly placed. The usual course of action 
 is as follows: The attending physician will consult with his con- 
 freres. Some will opine that it is, others that it is not, yellow fever. 
 One who has had some experience with the disease, a so-called 
 expert, is finally called in and, we will presume, verifies the diagnosis 
 of yellow fever. As an immediate result of this declaration the 
 physicians of the place, and with them the public, divide into two 
 antagonistic camps, one maintaining that the disease is 3 r ellow fever, 
 the other that it is not. And thus, with much wrangling and dis- 
 order and under the most discouraging circumstances, the work 
 of preventing the spread of the disease is inaugurated. The effort 
 to stamp it out then becomes a veritable campaign, not only against 
 the mosquito, but against a usually small but determined party of 
 opposition among the people. Such a condition of affairs would 
 not exist if the diagnosis could be promptly established beyond ques- 
 tion or cavil. 
 
 To attain this being impossible with the diagnostic means at 
 present at our command, I pass on to speak of what seems to me a 
 most important indirect prophylactic measure, one which may do 
 much to offset the results of our present inefficiency to promptly 
 establish an absolutely correct diagnosis — and that is education. 
 
 EDUCATION AS A PROPHYLACTIC FACTOR 
 
 The people in general, and the medical profession as well, should 
 be taught the truth about yellow fever, its comparatively low mor- 
 tality as treated at present, and the facility with which the disease may 
 be avoided and controlled. In a community which is well informed 
 
on these points the presence of a case of yellow fever could be an- 
 nounced without any fear of alarm or panic and the measures to 
 prevent its propagation put in force at once without clamor or delay. 
 The physician could act simply on the merits of the case from a pro- 
 fessional standpoint. If the disease under observation presented the 
 symptoms of yellow fever, he would announce it as such without 
 stopping to consider or, for the time being, trying to determine from 
 whence it came or obscure his judgment with considerations as to the 
 effect of his diagnosis on the business interests of the locality or on 
 his own personal interests. Such a condition of affairs is much to be 
 desired and with patience and preserverance may be attained. 
 
 The education of the public on this subject acts not only in this 
 indirect manner, but directly as well, for it will so guide public 
 opinion that it will be possible to practically eliminate the transmit- 
 ting factor of the disease, the mosquito, the stegomyia calopus. And 
 as it is impracticable to select only the stegomyia calopus for destruc- 
 tion, a campaign against this mosquito must be a general one, and also 
 include those responsible for the transmission of malaria, filaria, etc., 
 thus removing from the Tropics and subtropics some of the most 
 important causes of morbidity and mortality, and which heretofore 
 have been serious obstacles to their political, commercial, and indus- 
 trial progress. Education on this subject, therefore, I consider of 
 prime importance in the prophylaxis of yellow fever, and it is sur- 
 prising how little has been done or is being done on this line. 
 
 The writer in his report to the surgeon-general on the yellow fever 
 epidemic at Laredo, Tex., in 1903, said : 
 
 " Insistent and continued efforts should be made through the public 
 press and other available means to educate the people within the 
 sphere of influence of the stegomyia fasciata (calopus), so that they 
 will learn to protect themselves against the invasion or spread of 
 yellow fever among them by destroying the means for the propaga- 
 tion of said mosquito and by protecting themselves against the mos- 
 quito by efficient screening. Above all, to eradicate the existing fear 
 in the medical profession as well as among the laity, of declaring 
 the presence of yellow fever. If the first case presenting the slightest 
 suspicious symptoms of that disease were promptly made public and 
 the proper modern precautions taken, there would be no danger of 
 the disease spreading. In fact, the public should be taught to ac- 
 knowledge the existence of yellow fever in their midst with the same 
 equanimity as they do in the case of measles or scarlatina." 
 
 And again, in the report of the epidemic in Vicksburg, Miss'., in 
 1905, the writer stated : 
 
 " There is still much ignorance and skepticism (on the subject of 
 the method of transmission of yellow fever). An effort should be 
 
8 
 
 made to overcome this by widely distributing pertinent literature on 
 the. subject. And as it is reasonable to suppose that in spite of the 
 progress already made and being made to eradicate this disease from 
 Tropical and subtropical America, it will continue to harass us for 
 many years to come, it is believed that a campaign of education 
 should be begun with the young. All important facts pertaining to 
 the transmission of yellow fever by the stegomyia fasciata (calopus), 
 and the mode of propagation of this mosquito should be taught in 
 the public and private schools and colleges in infectible territory. 
 There may be seen in this way a good chance to completely destroy 
 the stegomyia in its present habitat, and even if not successful in 
 entirely destroying it, the great advantage will have been gained that 
 when yellow fever should make its appearance in a locality the work 
 of the sanitarian in checking or stamping out the disease would be 
 made easy indeed and the usual panic with its discomforts and 
 financial losses avoided." 
 
 My experience in these two epidemics and what I have seen else- 
 where has confirmed in my mind the importance of this matter. I be- 
 lieve and would recommend that the method of transmission of yellow 
 fever, and malaria as well, be taught in the schools wherever these 
 diseases are liable to occur. The subject should be taught in the pri- 
 mary grades, for what children then learn they will retain. To 
 obtain the desired result the most elementary teaching would suffice. 
 Children may be taught to dread a mosquito as they now do other 
 insects that are less harmful. In the higher grades, with little labor 
 cr time, the reasons for this fear of the mosquito may be demon- 
 strated, as also the methods of exterminating the insect and of pro- 
 tecting one's self against its bite. 
 
 ULTIMATE KESULTS OP EDUCATION. 
 
 With the above idea disseminated among the people it would not 
 be long before public opinion would demand with irresistible force the 
 drainage of swamps and lowlands and the inspection of houses and 
 premises to see that they were free of breeding places for mosquitoes. 
 
 To have open cisterns, water barrels, bottles, broken crockery, or, in 
 fact, any receptacle capable of holding water exposed for any length 
 of time, would be considered as much a nuisance and a menace to 
 (lie public health as ill-ventilated and crowded tenements, dirty 
 sheet-, defective sewerage, and the many other dangers which at 
 present excite the social and political activities of national, state, and 
 municipal authorities. Such a system would, within a comparatively 
 short time, eliminate all danger from both yellow fever and malaria. 
 
PROPHYLACTIC MEASURES INDICATED IN INFECTIBLE TERRITORY. 
 
 We will now consider more in detail the prophylactic measures that 
 should be observed in infectible territory. These may be divided 
 into two classes, to wit : (a) Measures directed against the introduc- 
 tion of yellow fever from abroad; (b) those looking to the prevention 
 of its spread when it has been introduced. 
 
 Maritime quarantine. — Measures employed to prevent the entrance 
 of infection from abroad are usually included under the term " mari- 
 time quarantine " and are at present well provided for in the United 
 States by an efficient national quarantine establishment, which is an 
 integral part of the United States Public Health and Marine-Hos- 
 pital Service. 
 
 The measures ordained against the introduction of yellow fever by 
 the quarantine regulations of this service are based on its well-known 
 period of incubation and the processes of disinfection on the mos- 
 quito transmission of the disease, and are directed to the destruction 
 of this insect both in its larval and adult stage. These measures may 
 be stated briefly as follows: 
 
 Vessels which may possibly be infected are detained at the port of 
 arrival five days after disinfection ; vessels known to be infected, six 
 days. The service has medical officers stationed at all the important 
 ports within the yellow-fever zone, and if the vessel is disinfected at 
 the port of departure under the supervision of this officer, the vessel 
 on arrival at a port of the United States within the infectible area 
 is subject to the following modified treatment: If arriving in five 
 days or less, she may be admitted to pratique without disinfection or 
 further detention than is necessary to complete the five days. If ar- 
 riving after five days and within ten days, she may be immediately 
 fumigated and admitted without detention. If arriving after a 
 longer voyage than ten days, she will be considered as not having 
 been subjected to any previous treatment. This last disposition is 
 based on the possibility that a case of yellow fever may have occurred 
 aboard and recovered within the time mentioned. 
 
 Passenger traffic from infected ports, without detention, is also 
 permitted by these regulations under the following conditions : 
 
 Vessels carrying such passengers must be in the best sanitary con- 
 dition and must lie at approved moorings in the open harbor. The 
 crew must not be allowed ashore at the port of departure. The 
 entrance of mosquitoes into the vessel must be prevented, and if they 
 do find ingress must be destroyed. Passengers and crew must be 
 certified as immune by the medical officer issuing the bill of health. 
 The evidences of immunity which may be accepted are proof of a 
 previous attack or ten years' residence in an endemic focus of yellow 
 fever. These regulations apply, of course, only during the close quar- 
 antine season — that is, from the 1st of May to the 1st of November. 
 
10 
 
 It will be noted that the above restrictions are liberal enough and 
 at the same time give adequate protection. 
 
 Referring for a moment to the evidence upon which certificates of 
 immunity are based, the writer is of the opinion that a ten years' 
 residence in an endemic focus should no longer be considered suffi- 
 cient, for with our present knowledge of the method of transmission 
 of yellow fever it is quite clear that any intelligent person taking- 
 certain simple precautions might very well live a lifetime in an 
 endemic focus and yet never be exposed to infection. 
 
 Measures against the spread of yellow fever. — With reference now 
 to class o — that is, preventive measures against the spread of yellow 
 fever once it has been introduced, we find that as a rule we are not 
 so well equipped. The principle of prophylaxis is, of course, pre- 
 cisely the same, but is much more difficult of application because we 
 have to deal with local and conflicting interests and the ignorance 
 of the people. Municipalities usually have a sufficiency of ordi- 
 nances and regulations covering prophylactic measures against yellow 
 fever, but unfortunately these are completely ignored except when 
 menaced by an epidemic, and then enforced with difficulty. These 
 ordinances have been enacted during a period of stress and excite- 
 ment, when yellow fever was present or dangerously near, and quickly 
 forgotten once the danger had passed. Now, this should not be, for 
 there is no reason why every port in infectible territory should not 
 be so administered as to make it noninfectible, so that if yellow fever 
 should gain an entrance from abroad its spread would be impossible. 
 To attain this I would outline the following plan : Education and the 
 formation of a public opinion that would look upon the mosquito not 
 only as a disagreeable pest but a very dangerous one as well ; proper 
 drainage; a corps of inspectors to examine all premises every ten 
 days, preferably once a week, to see that they are free from water 
 containers capable of harboring mosquito larvae; the screening or 
 covering with oil of water containers which can not be destroyed, or 
 the use of small fish where the above methods are not available; 
 the removal of unnecessary vegetation: the screening of dwellings 
 and other buildings. 
 
 In carrying out the above measures there is nothing that requires 
 any great expenditure of money or labor, and if efficiently performed 
 and consistently kept up it would be but a short time before the intro- 
 duction of a case of yellow fever into a locality so governed would be 
 unattended with danger and scarcely cause a ripple of excitement. 
 
 GENERAL PLAN FOE HANDLING AN EPIDEMIC. 
 
 Where the ideal conditions above mentioned do not prevail there is, 
 of course, imminent danger of the disease spreading. Steps must be 
 taken :it once to prevent this. The bases of preventive measures may 
 
11 
 
 be stated succinctly as follows : To prevent the infection of Stegomyia 
 mosquitoes by properly protecting all persons ill with yellow fever 
 during the first three days of the illness ; to protect the well from the 
 bite of the mosquito ; and, as a corollary to the above, the destruction 
 of all mosquitoes and their means of propagation. Given the requi- 
 site personnel, sufficient funds, and the necessary authority to enforce 
 measures to this effect and there would be little danger of the disease 
 spreading. These desiderata, however, are usually wanting or only 
 imperfectly supplied. The practical adaptation of the above propo- 
 sitions may be considered under the following heads : 
 
 1. Detection of cases or inspection. 
 
 2. Yellow fever hospital. 
 
 3. Martial law. 
 
 4. Detention camp. 
 
 5. Protection against the bite of the mosquito; screening, etc. 
 
 6. Extermination of mosquitoes, including oiling, fumigation and 
 the screening or destruction of water containers. 
 
 The details of the two latter are so well known and, in fact, so 
 simple that it seems unnecessary to take up the reader's time with a 
 discussion of them. Relative to the first three, which I consider of 
 great importance and which, in a way, form the tripod on which the 
 others rest, it is well to say a few words. 
 
 1. Detection of cases or inspection. 
 
 In order to put in force efficient prophylactic measures it is abso- 
 lutely necessary that all cases be reported immediately. For reasons 
 before stated this is difficult, and to those already given we may add 
 that during an epidemic many cases of fever do not call a phy- 
 sician at all. To surmount these obstacles, as well as the difficulty of 
 definitely recognizing the disease in its early stages, all cases of 
 pyrexia in which the reason of the abnormal temperature is not 
 manifest should be treated prophylactically during the first three 
 days as though they were yellow fever, or until a positive diagnosis 
 to the contrary is made. For the purpose of reaching all cases of 
 fever a thorough inspection is required. Every dwelling in the in- 
 fected area must be inspected daily, or, better, twice a day, by com- 
 petent inspectors, persons capable of reading the clinical thermometer. 
 All cases of pyrexia discovered by the inspectors should be imme- 
 diately reported to the officers in charge of the screening and fumi- 
 gating parties for proper action. The patient having been protected 
 against the bite of the mosquito by screening and his dwelling and 
 the surrounding houses fumigated for the purpose of destroying any 
 possibly infected mosquitoes, the question of diagnosis may safely 
 be left to be determined later. Whenever possible the patient should 
 be removed to the hospital. 
 
L2 
 
 2. Yellow-fever hospital. 
 
 This brings us to the second prophylactic measure advocated 
 above — the advantage, and indeed necessity, of a yellow-fever hos- 
 pital in dealing successfully with an epidemic. 
 
 There is a prejudice among the people against the term " yellow - 
 fever hospital," hence it would be as well to yield to this prejudice 
 and call it an " isolation " or " observation " hospital. The important 
 point is that this hospital be absolutely mosquito proof, and that it 
 be made attractive, be clean and well managed, so that the people 
 may be drawn to it and feel that they will be as well or better 
 cared for in the hospital as in their own homes. The greater the 
 number of fever patients that can be removed to the hospital the 
 easier will be the task of stamping out the disease. 
 
 Such cases as in the opinion of the sanitary officer can not be prop- 
 erly screened in their homes should be compelled to go to the hospital. 
 The transfer of the patient must be accomplished with such pre- 
 cautions as will prevent the possibility of his being bitten by a mos- 
 quito — under a mosquito-bar or in a screened ambulance. 
 
 3. Martial law. 
 
 To make the inspection thorough and effective and to compel the 
 transfer of the sick to the hospital when necessary, authority is re- 
 quired. In a republican form of government this authority is usually 
 wanting and these measures have to be carried out inefficiently and 
 in the face of great opposition. 
 
 To obviate this the writer would advocate that martial law be de- 
 clared in epidemics when the conditions are such as to warrant it. 
 This legal procedure is frequently invoked when the menace to life 
 and property is not nearly so great as in an outbreak of yellow fever 
 or other infectious or contagious disease. 
 
 With martial law to support the sanitary officer the prophylactic 
 measures herein advocated could be enforced in every detail and an 
 outbreak of yellow fever effectually controlled. It is easy to under- 
 stand why this agent was not invoked prior to the demonstration 
 of the transmitting factor of yellow fever, when our efforts to control 
 the disease were rather vague and uncertain; but to-day, when our 
 system ma} 7 be made so precise and certain it seems almost criminal 
 not to take advantage of such a powerful auxiliary. 
 
 Tii our epidemics (lie sanitarian, unsupported by authority, is 
 obliged to lose much precious time and energy in his efforts to gain 
 the good graces and plaudits <d' the populace, so that he may be per- 
 mitted to perform his work imtrammeled. 
 
13 
 
 4. Detention camp. 
 
 In most epidemics it is necessary to provide means to permit per- 
 sons to leave the infected district without danger of carrying the 
 disease elsewhere. This may be accomplished by a so-called " de- 
 tention camp," where those wishing to leave the infected locality may 
 do so after being detained under observation for the time requisite to 
 assure their freedom from infection. 
 
 With our present knowledge of the transmission of yellow fever 
 it is unnecessary to establish these " camps," as heretofore, in out- 
 of-the-way or inconvenient places. On the contrary, they may be 
 located with perfect safety within the infected district so long as the 
 detained persons are kept in mosquito-proof quarters and, when their 
 period of observation has terminated, are taken to their destination 
 in mosquito-proof conveyances while within the infected area. 
 
 It is plain, however, that in a properly educated community where 
 the measures above advocated can be put in practice, there will 
 scarcely be any necessity for a detention camp. 
 
 In the foregoing pages the writer has endeavored to outline a 
 scheme or plan of prophylaxis which he feels quite sure will do the 
 work expected of it. The machinery is there, but where is the power 
 to set it in motion? To start it successfully, smoothly, and without 
 friction, some central authority with the necessary means and power, 
 acting surely and swiftly, must be provided. This should be the 
 function of the Government. 
 
 PROPHYLACTIC MEASURES SUGGESTED BY THE FRENCH COMMISSION 
 OP THE PASTEUR INSTITUTE. 
 
 Much interest is attached to the means of prophylaxis suggested 
 by the results obtained hy the French commission of the Pasteur 
 Institute in their report on the investigation of yellow fever, pub- 
 lished in the Annals of the Institute in November, 1903, to wit : 
 
 1. An injection of virulent blood serum which has been heated for 
 five minutes at a temperature of 55 °C. confers a relative immunity, 
 which may become complete if followed by the injection of a very 
 small quantity of virulent serum. 
 
 2. The injection of defibrinated blood which has been kept under 
 liquid vaseline for eight days confers a relative immunity. 
 
 3. The serum of a convalescent is endowed with preventive proper- 
 ties. 
 
 4. The immunity conferred by the serum of the convalescent is 
 still in evidence at the end of twenty-six days." 
 
 a Abstract of Report, French Yellow Fever Commission ; Annual Report. 
 U. S. Public Health and Marine-Hospital Service, 1904. 
 
14 
 
 Further study on this line may give us an immunitive serum which 
 will be of great value in controlling yellow fever. 
 
 However, even though we attain this and, furthermore, discover 
 the etiological factor in yellow fever we will still, in a great measure, 
 have to depend on the means of prophylaxis herein outlined, and I 
 desire, therefore, to impress upon the reader the importance of edu- 
 cation as a prophylactic factor and the necessity of clothing the 
 sanitary officer with the requisite power and authority to enforce 
 the measures that we now have at our command, which are simple 
 and efficient. 
 
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