COLUMBIA LIBRARIES OFFSITE HEALTH SCIENCES STANDARD HX64081125 R J496. P2 F63 The nature, manner i RECAP Simon Floxnor The nature ... of infantile paralysis RJ^f The Rockefeller institute for Medical Research.) The Rockefeller [nstitute for Medical Research has beer appealed to by so many physicians and laymen for information and advice on the subject of infantile paralysis, that it has Beemed desirable to relate the Pacts of presenl knowledge concern- ing certain highly pertinenl aspects <>!' the disease, together with deductions of practical importance derived from them. Nature. Infantile paralysis is an infectious and com- municable disease which is caused by the invasion of the central nervous organs the spinj] cord and brain — of a minute, filterable microorganism which has now been secured in artificial culture and as such is distinctly visible under th- higher powers of t he microsc< >pe. Location of the microorganism or virus in the sick. The vims of infantile paralysis, as the micro- organism causing it is termed, exists constantly in the central nervous organs and upon the muc- ous membrane of the nose and throat and of the intestines in persons suffering Prom the disease; it occurs less frequently in the other internal or- gans, and it has nol been detected in the general circulating blood of patients. Location of the virus in healthy persons. Although the microorganism of infantile para- lysis is now known, the difficulties attending its artificial cultivation and identification under the microscope are such as to make 1 futile the employ- ment of ordinary bacteriological tests for its de- tection. Nevertheless, the virus can be detected by inoculation tests upon monkeys, which animals develop a disease corresponding to infantile para- lysis in human beings. In this manner the facl has been determined that the mucous membrane of the nose and throal of healthy persons who have been in intimate contact with acute cas< infantile paralysis may become contaminated with the vims, ;ind thai such contaminated persons. without falling ill themselves, may convey the in- fection to other persons, chiefly children, who de- velop the disease. Relation of virus to types of the disease. The virus has, apparently, an identical distri bution irrespective of the types or severity of oases "i' infantile paralysis. Whether the cases correspond with the so-called abortive form- ol the disease in which definite paralysis ^\' the muscles docs not occur ;>t all, or is so Blight and fleeting as often to escape detection; whether they •J correspond with the meningeal forms in which tlif symptoms resemble those of acute meningi- tis with which muscular paralysis may or may not be associated; or whether they consist of the familiar paralytic condition, the virus is presenl not onlv within the nervous organs, but also up- on the mucous membranes of the nose, throat and intestines Escape of the virus from the body. Microorganisms which convey disease escape from the body of an infected individual in a man- ner enabling them to enter and multiply within fresh or uninfected individuals in such a man ncr as to cause further disease. The virus "I' in- fantile paralysis is known to Leave the infected hu- man body in the secretions of the nose, throat, and intestines. It also escapes from contaminated healthy persons in the secretions of the nose and throat. Whether it ever leaves the infected body in other ways is unknown. At one time certain experiments seemed to show that biting insects and particularly the stable fly might withdraw the vims from the blood of infected persons and in oculate it into the blood .if healthy persons. Bui as the vims ha- never been detected ill tile blood of human being8 and later experiments with the stable fly have not confirmed the earlier one-. this means of escape of the virus must he consid- ered doubtful. On the other hand, it has been shown by experiments on animals, so ihat the same facts should be regarded as applicable to human beings, that the virus seek t<> escape from the body by way of the nose and throat, net only when inoculation takes place through these mem branes« bni also when the inoculation is experi 3 mentally made into the abdominal cavity, the blood, or Ili<' brain itself. From this it is con- cluded thai the usual means of escape of the virus is by way of the ordinary secretions of the nose and throat and, after swallowing these, with the discharges of the intestines. Entrance of the virus into the body. The virus enters the body, as a rule if not ex- clusively, by way of the mucous membrane of the nose and throat. Saving gained entrance to those easily accessible parts of the body, multiplication of the vims occurs there, after which it penetrates to the brain and spinal cord by way of the lymph atic channels which connect the upper aasal mem- brane with the interior of the skull. Whether tbe virus ever enters the body in any other way is nn known. Certain experiments already alluded to make it possible that it may be inoculated into the blood by insects, and other experiments have shown that under peculiar and extraordinary con ditions, it may in monkeys enter through the in teslines. But while the latter two modes of in fection may operate Bometimes, observations up on human eases of infantile paralysis and upon animals all indicate thai the main avenue of en trance of tbe virus into the bodj is by way <>!' the upper respiratory mucous membrane thai is, the membrane of the nose and throat. Resistance of the virus. The physical properties of the virus of infan tile paralysis adapt it well for conveyance to the nose and throat. Being contained in their secre tions, ;t i- readily distributed by coughing, sneez Lng, kissing, and by means of fingers and articles contaminated with these secretions, as well as with the intestinal discharges. Moreover, as the virus is tin-own off from the body mingled with the secretions, it withstands for a long time even the highest summer temperatures, complete dry ing, and even the action of weak- chemicals, such as glycerin and carbolic acid, which destroy or- dinary bacteria. Hence mere drying of the secre- tion- is ao protection; on the contrary as the dried secretions may he converted into dnst which is breathed into the nose and throat, they become a. potential source of infection. The survival of the virus in the secretions is favored by weak day lighl and darkness, and hindered by brighl day light and sunshine. 11 is readily destroyed by ex- posure to sunlight. Conveyance by insects. Since epidemics of infantile paralysis always arise during the period of warm or summer weath er, they have l»'«'ii thought of as possibly being connected with or dependent on insect lif<\ The blood-sucking insects have especially come under suspicion. Experiments have been made with hit ing (lies, bed-bugs, mosquitoes, and with lice. Neither mosquitoes nor lice seem able to take the virus from the blood of infected monkeys <>r to retail! it for a tune in a living -tale. In one in -lance, bed bugs have been made to take up the virus from the blood of monkeys, hut they did not convey it by biting to healthy monkeys. Certain experiments did indicate that the biting stable fly could both withdraw the vims from the blood of infected ;ind nrniivcv it to the hlood of healthy 5 monkeys, which became paralyzed. But more re- cenl studies have failed to confirm the earlier ones. Moreover, experimentally inoculated monkeys dif- fer in one way from human beings suffering from infantile paralysis, for while the virus may appear if the blood of the former, it lias never been de tected in lli< i blood of the latter. The ordinary or domestic fly may become contaminated with the virus contained in the secretions of the body and serve as the agenl of its transportation to persons and to food with which they come into contact. Domestic Mies experimentally contaminated with the virus remain infective for 48 hours or longer. While our present knowledge excludes insects from being active agents in the dissemination of infantile paralysis, they nevertheless fall under suspicion as being potential mechanical carriers of the virus of that disease. Conveyance by domestic animals. The attention which the recenl epidemic of in Inutile paralysis has drawn to the diseases at- tended by paralysis has led to the discovery that domestic animals and pets are subject to parak tic diseases. The animals which have especially come under suspicion as possibly distributing! the germ of infantile paralysis are poultry, pigs, and dogs, and cats. Bui in isolated instances, sheep, cattle, and even horses have been suspected. All Ihese kinds of animals are subjed to diseases in which paralysis of the legs and other parts of He' bodj sometimes appear. In not a few instances, paralytic disease among poultry or pigs have been noted to coincide with the appearance of cases <>!' infantile paralysis mi a farm or in a commun Hy. Experimental studies have, however, exclu dec! the above-mentioned animals from being car- riers of the virus of infantile paralysis. The para- lytic diseases which they suffer have long been known and are quite different from Infantile para- lysis. Their occurrence may be coincidental; in no instance investigated has one been found to be responsible for the other. Routes of travel. Studies carried out in various countries in which infantile paralysis has been epidemic all indicate that, in extending from place to place or point to point, the route taken is that of ordinary travel. This is equally true whether the route IS by water or land, along a simple highway or the line of a railroad. In other words, the evidence derived from this class of studies Confirms the evidence obtained from oilier sources in connecting the distributing agency intimate- ly with human beings and their activities. Survival of the virus in the infected body. The virus of infantile paralysis is destroyed in the interior of tin- body more quickly ami com pletely than, in some instances, in the mUCOUS membrane of the nose and throat. It has been found in monkey-, in which accurate experiments ean he carried out, thai the virus may disappear from the brain and spinal cord within a few days to three weeks after the appearance of the para lysis, while at 1 he same lime il is st ill presenl up on the mucous membranes mentioned. The long est period after inoculation in which Hie virus has been detected in the mucous membrane of the nose and throat of monkeys is six months. It is far more difficult to detect the human than the monkey carriers of the virus since, as directly ob- tained from human beings, the virus displays a low degree of Lnfectivity for monkeys; while once adapted to monkeys, the virus becomes incredi- bly active, so that minute quantities are capable of ready detection by inoculation tests. Vet in an undoubted instance of the human disease, the virus was detected in the mucous membrane of the throat five months after its acute onset. Hence w,» possess conclusive evidence of the occurrence of occasional chronic human carriers of the virus of infantile paralysis. Fluctuation in epidemics. Not all epidemics of infantile paralysis arc equally severe. Indeed great variations or fluc- tuations are kown to occur not only in the number of cases, hut also in the death rate. The extremes are represented by the occasional instances of in- fantile paralysis known in every considerable com- munity and from which no extension take- place, and the instances in which in a few days or weeks the number of cases rises by leaps and bounds into the hundreds, and the death rate reaches 20 per cent or more of those attacked. While all the factors which determine this discrepancy are not known, certain of them have become apparent. A factor of high importance is the infective pow- er or potency, or technically Btated the virulence, of t he microorganism or virus causing the disease. This virus is subject to fluctuations of intensity which can hest l»e illustrated by an example. The virus as ordinarily present in human beings even during Bevere epidemics has l<»\\ infective power 8 for monkeys. But by passing it from monkey to monkey, it tends to acquire after a variable number of such passages an incredible activity. However, occasional samples of the human vi- rus refuse to be thus intensified. But once ren- dered highly potent, the virus may be passed from monkey to monkey through a long but not indefinite series. Finally, in some samples of the virus a1 least a reverse change takes place — the virus begins to lose its virulence until it re- turns to the original or even to a diminished de- gree of infective power. In this respect the be- havior of the virus corresponds to the onset, rise and then the fall in number and severity of eases as observed in the course of epidemics of infan- tile paralysis and other epidemic diseases. Hence either a new active specimen of the virus may be introduced from without which, after a certain number of passages from person to person, ac- quires a high potency; or a specimen of virus al- ready present and left over from a. previous epi- demic after a resting period and similar passages, again becomes active and reaches an infective power which equals or even exceeds that origin- ally possessed. Another but more indefinite factor relates to the degree of susceptibility among children and others affected which at one period may be greater or less than at another. Varying individual susceptibilities. Nbl all children and relatively few adults are susceptible to infantile paralysis. Young chil- dren are more susceptible generally speaking than older ones; but no age can be Baid to be absolutely insusceptible. When several children exist in a family or in a group, one or more may be affected, while the others escape or seem to escape. The closer the family or other groups an- studied by physicians, the more numerous it now appears are the number of cases among them. This means that the term infantile par- alysis is a misnomer, since the disease arises without causing any paralysis whatever, or such slight and fleeting paralysis as to be difficult of detection. The light or abortive cases, as they are called, indicate a greater general suscepti- bility than has always been recognized; and their discovery promises to have far-reaching conse- quences in respect to the means employed to limit the spread or eradicate foci of the disease. Period of incubation. Like all other infectious diseases, infantile par- alysis does not arise at once after exposure, but only after an intervening lapse of time called the pniod of incubation. This period is subject to wide limits of fluctuation: in certain instances it has been as short as two days, in others it lias been two weeks or possibly even longer. But the usual period does not exceed about eight days. Period of infectivity. Probably the period at which the danger of communication is greatest is during the very early and acute Btage of the disease. This state nient must he made tentatively since it depends on inference, based <>n general knowledge of in fection, rather than on demonstration. Judging from experiments on animals, the virus tends not 10 to persisl in the body longer than four or five weeks excepl iii those exceptional instances in which chronic carriage is developed. Hence cases of infantile paralysis which have been kepi under supervision for a period of six weeks from tlie onset of the symptoms may be regarded as prac- t iealh free of danger. Protection by previous attack. Infantile paralysis is oik? of the infectious > one attack. The evidence derived from experi- ments on monkeys is conclusive in showing that an infection which ends in recovery gives pic lection from a subsequenl inoculation. Observa- tions upon human beings have broughl out the same fact, which appears to he generally true. and to include all the forms of infantile paraly sis, namely the paralytic, meningeal, or abortive, which all confer immunity. Basis of the immunity. The blood of normal persons and monkeys is not capable of destroying or neutralizing the effecl of the virus of infantile paralysis. The blood of persons or monkeys who have recov ered from the disease is capable of destroying or neutralizing the effecl of the virus. The insus ceptibility or immunity to Bubsequenl infection. whether occurring in human beings after ex posure or monkeys after inoculation, rests on the presence of the destroying substances, the bo called immunity bodies, which arise in the in I l ternal organs and are yielded to the blood So long as these immunity bodies persisl in the body, protection is afforded; and their presence has been detected twenty years or even longer after recovery from infantile paralysis. Experiments have shown thai the immunity bodies appear in the blood in the course of even the mildest at- tack of the disease, which \';[d explains why pro tection is afforded irrespective <>f the severity of the case. Active immunization. Protection has been afforded monkeys againsl inoculation with effective quantities of the virus of infantile paralysis by previously subjecting them to inoculation with sub-effective quantities or "loses of the virus. By this means and without any evidenl illness or effect of the protective inoculation, complete immunity has been achieved. Bui the method is not perfect since in certain instances not only was immunity not ob- tained, but unexpected paralysis intervened. In the instances in which protection was accom plished, the immunity bodies appeared in the blood. Passive protection. I'.\ transferring the blood of immune monkeys to normal or untreated ones, they can he ren dered insusceptible <>r immune, and the immunity will endure for a relatively shint period during which the passively transferred immunity bodies persist. The accomplishment of passive immun ization is somewhat uncertain, and its brief dura- tion renders it useless for purposes of pro- tective immunization. Serum treatment. On the other hand, a measure of success has been achieved in the experimental serum treat- ment of inoculated monkeys. For this purppse blood serum derived either from recovered and protected monkeys or human beings has been employed. The serum is injected into the mem- branes aboul the spinal cord, and the virus is inoculated into the brain. The injection of serum musl be repeated several times in order to be effective. Use of this method has been made in a few instances in France where the blood Berum derived from persons who had recovered from infantile paralysis lias Keen injected into the spinal membranes of persons who have just be- come paralyzed. The results are said to be promising. Unfortunately, the quantity of the human immune scrum is wry limited, and no other animals than monkeys seem capable of yielding an immune Berum and the monkey is not a practicable animal from which to obtain supplies. Drug treatment. Thf virus of infantile paralysis attacks and attaches itself to the central nervous organs. Hence it is reached not only with difficulty be- cause nature has carefully protected those sensi- tive organs from injurious materials which may L3 gain access to the blood, but it must be counter- acted by substances and in a manner that will not themselves injure those sensitive parts. The ideal means to accomplish this purpose is through the employmenl of an immune serum, since serums are among the least injurious thera- peutic agents. The only drug which has shown any useful degree of activity is hexamethylena- min which is itself germicidal, and has the merit of entering the membranes, as well as the sub- stance of the spinal cord and brain in which the virus is deposited. But experiments <>n monkeys nave shown this chemical to be effective only very early in the course of the inoculation and only in ;i part of the animals treated. Efforts to modify and improve this drug by chemical means have up to the present been only partially sue cessful. The experiments have not yet readied the point where the new drugs are applicable to tic treatment of human cases of infantile paral- vsis. Practical Deductions and Applications. 1. The chief mode of demonstrated convey ance of the virus is through the agency of hu- man beings. Whether still other modes of dis- semination exist is unknown. According to our present knowledge, the virus leases the body in the secretions of the nose and throat and in the discharges from the intestines. 'The conveyers of the virus include persons ill of infantile par alysis in any of its several forms and irrespeel ive of whether they are paralyzed or not, and such healths persons who may have become con laminated le, attendance on or association with 1 I the ili. How numerous the latter class may be is unknown. But all attendants on or associates of the sick are suspect. These healthy carriers rarely themselves fall ill of the disease; they may, however, he the source of infection in others. On the other hand, the fact that infan- tile paralysis is very rarely communicated in era! hospitals to other persons, whether doctors, nurses, or patients, indicates that its spread is subject to ready control under restricted and supervised sanitary conditions. 2. The chief means by which the secretions of the nose and throat are disseminated is through the act of kissing, coughing, or Bneezing. Hence during the prevalence of an epidemic of infantile paralysis, care should be exercised to restrict the distribution as far as possible through these common means. Habits of Belf denial, care, and cleanliness and consideration for the public welfare can be made to go very far in limiting the dangers from these Bources. Moreover, since the disease attacks hy prefer ence young children and infants, in whom the secretions from the nose and month are wiped away by mother or nurse, the fingers of these persons readily become contaminated. Through attentions on other children or the preparation of food which may be contaminated, the virus may thus be conveyed from the sick to the healthy. The conditions which obtain in a house hold in which ;i mother waits on the sick child and attends tin' other children ;nv directlj con trasted with those existing in a well-ordered hospital: the on.- is ;i menace, ili' 1 other a pro lection to iIm- comunity. Moreover, in homes (| jr practice of carrying small children about L6 and comforting them is the rule, through which not only the Lands, but other parts of the body and the clothing of parents may become con- taminated. 3. Flies also often collect about the nose and mouth of patients ill of infantile paralysis and feed on the secretions, and they even gain access to the discharges from the intestines in homes unprotected by screens. This fact relates to the domestic fly, which becoming grossly contamin- ated with the virus, may deposit it on the nose and mouth of healthy persons, or upon food or eating utensils. To what extent the biting stable fly is to be incriminated as a carrier of infection is doubtful; but we already know enough to wish to exclude from the sick, and hence from men- acing the well, all objectionable household in sects. Food exposed to sale may become contamin- ated by fles "!• Prom Angers which have been in contact with secretions containing the virus; hence food should not be exposed in shops ;md no person in attendance upon ;i case of infantile paralysis should be permitted to handle food for Bale to the general public. 4. Protection to the public can be best se- cured through the discovery and isolation of those ill of the disease, and the sanitary ( fcrol of those pei-sons who have associated with the Bicb and whose business calls them away from home. Both these conditions can be Becured without too greal interference with the comforts and the rights of individuals. In the first place where home- are not suited to the care of the ill so thai othei children in the same or adjacent families are exposed, the par Hi ent should consent to removal to hospital in the interesl of the sick child itself, as well aa in the interest of other children. But this removal or care must include do1 only the frankly paralyzed cases, hut also the other forms of the disease. In the event of doubtful diagnosis, the aid of the laboratory is to be soughl since even in the mild- est eases changes will he detected in the cere brospinal fluid removed by lumbar puncture. If the effort is to be made to control the disease by isolation and segregation of the ill, then these means musl be made as inclusive as possible. It is obvious that in certain homes isolation can be carried out as effectively as in hospitals. But what has been said of the small incidence of cases of the disease among the hospital per SOnnel and those with whom they come into con- tact, indicates the extent to which persona] care of the body by adults and responsible people can diminish the menace which those accidentally or unavoidably in contact with the ill are to the community. Care exercised not t<> scatter the se cretions of the nose mid throat by spitting, coughing and Bneezing, the free use of clean handkerchiefs, cleanliness in habits affecting especially the hands and face, changes of clothes, etc., should all serve to diminish this danger. In the end, the early detection and isolation of the cases of infantile pnral\Ms in all of its forms, with the attendant control of the house holds from which they come, will have t" be re lied upon as the chief measure of staying the progress of tin- epidemic. ."». The degr f Busceptibilitj "f children and other members of the community '" in fantile paralysis is relatively -mall and is 17 definitely lower than to such communicable dis- eases as measles, scarlet fever, and diphtheria. This fact in itself constitutes a measure of con- trol; and while it does not justify the abate- ment of any practicable means which may be employed to limit and suppress the epidemic, it should tend to prevent a state of over-anxiety and panic from taking hold of the community. 6. A percentage <»t' persons, children partic- ularly, die during the acute stage of the dis- ease. This percentage varies from five in cer- tain si vere epidemics t<> twenty in others. The average death rate of many epidemics has been below 10 per cent. A reported high death rate may not be actual, hut only apparent, since in every instance the death will he recorded, while many cases which recover may not he reported at all to the authorities. Iii the present in- stance it is too early in the course of the epi- demic to calculate the death rate which may prove to l»' considerably lower than it now senn> to he. 7. Of those who survive, a part make com plete recoveries, in which no crippling whatever remains. This number is greater than is usually Bupposed, because it includes not < » 1 1 1 \ the relatively large number of Blight or abortive oases, hut also a considerable number of cases in which more or less of paralysis was presenl at one time. The disappearance of the paralysis may he rapid or gradual may ^^' complete in a few days or maj require Beveral weeks "i Iliollt lis. The remainder, and unfortunately not a small number, Buffer Borne degr t permanent crip is pling. But even in this class, the extent to which recovery from the paralysis may occur is very great. In many instances the residue of paralysis may be so small as not seriously to hamper the life activities of the individual; in others in whom it is greater it may be relieved or minimized by suitable orthopedic treatment. But what it is imperative to keep in mind is that the recovery of paralyzed parts and the restoration of lost muscular power and function is a process which extends over a long period of time — that is, over months and even years. So that even a severely paralyzed child who has made little recovery of function by the time the acute stage of the disease is over, may go on gaining for weeks, months, and even years until in the end he has regained a Large part of his losses. Fortunately, only a very small number of the attacked are lefl severely and helplessly crippled. Lamentable as it is that even one should he so affected, it is neverthe- less a reassurance to know that so many recover altogether and so much of what appears to be permanenl paralysis, disappears in time. There exists at present no safe method of preventive inoculation or vaccination, and no practicable method of specific treatment. The prevention of the disease must he accomplished through general sanitary means; recovery from the disease is a spontaneous process which can he greatly assisted by proper medical and sur gical care, [nfantile paralysis is an infectious disease, due to a definite and specific microor ganism or virus; recovery is accomplished by a process of immunization winch takes place during the acute period of the diseasi Tic tendency of the disease i- toward recovery ami ID I I •• ''■■"■■■■•< ' t ' ■ >' ' ■.-..: .... I I . ,, I I • • • ' i r> it is chiefly, or only because the paralysis in some instances Involves those portions of the brain and spinal cord which control respiration or breathing and the heart's action, that death results. Finally, it should be added that not since L907, at which time the great epidemic of infantile par- alysis, or poliomyelitis, appeared in this country, has the country or this State or city been free of the disease. Bach Summer since has seen some degree of accession in the number of the ca the rapid rise in the number of cases this year probably exceeds that of any previous year. But it must be remembered that in 1908 several thou- sand cases occurred in the greater city — possibly indeed many cases of and deaths due to the dis- ease were never reported as such. Hence the present experience, Bevere and serious as it is, is not something new; the disease has been Be verely epidemic before and was brought under control. The knowledge regarding it now is far greater than it was iii L908; and the forces of the City which are dealing with the epidemic are probably better organized and in more general co-operation than ever before. The outlook, therefore, should not be regarded as discourag inir. 20 DATE DUE MAt x blum APK 5 Sfe; A D ' . Hi i\ 1 ^ Jj j! i fl