(Continued from p_ 237.)

Transcription

1 303 DYSENTERY AMONG TROOPS IN QUETTA. PAR'r II E.-NOTES ON THE AM<EBJE FOUND. By LIEUTENANT-COLONEL D. T. M. LARGE, Royal Army Medical Corps. AND O. K. SANKARAN. Indian Medical Department. (Continued from p_ 237.) DURING the year 932 large numbers of amffible were found in Quetta. Cases showing these amffibre increased in number during the dysentery season and fell off as the cold weathet came Oil, when there was practically no dysentery. Many of these amffibre were diagnosed Entamreba histolytica in spite of the absence of contained red blood-corpuscles on the grounds of active and progressive motility, together with clear pseudopodia in an amooba measuring from 20 to 40 microns. Wenyon in his textbook Protozoology" (926) states: "The tissue invading form of E. histolytica as a rule varies in diameter from 20 to 30 microns, but larger or smaller forms may occur. A very characteristic feature of the amffiba is its activity, large blunt pseudopodia being formed and withdrawn in rapid succession. Though occasionally E. coli will be seen to move with an activity almost if not quite equal to that of E. histolytica, this is rarely the case, and the energetic movements of E. kistolytica serve as one of its most important distinguishing features. The number of amoobre in any particular specimen containing red blood-corpuscles varies considerably. Sometimes as many as 25 per cent will show them, while in other cases a long search will reveal only a single one or none at all. As regards the large amffib~ from 5 to 20 microns or more, if they occur in dysenteric stools, and are very active, they are probably E. histolytica." It was on grounds such as these, and on others less important, that the diagnosis of amffibic dysentery was made in 932 in this laboratory. Much time was spent on searching every case, with the result that on compiling the figures for the year it was found that amffibic dysentery formed a considerably larger proportion of the Quetta dysentery than is normally the case elsewhere in India. Such finding naturally was regarded somewhat with suspicion by colleagues to whom it was submitted for criticism, chiefly in connection with the fact that E. histolytica had been reported in many of the cases in the absence of contained red blood-corpuscles. In order to provide a better foundation for the diagnosis of amoobic dysentery in 933, records were kept of every case in which an amooba was

2 304 Dysentery among Troops in Quetta found, the amoobre being described in detail in each case. A total of 66 cases showing amoobre was found amongst,042 cases of dysentery and diarrhooa, and tabulated as follows :- () Bacillary dysentery cases (2) Clinical dysentery cases with indefinite exudate microscopically (3) Diarrhrea cases showing neither blood nor pus cells microscopically 448, showed ami:ebre in , " , " 29, The amoobre have been divided, for descriptive purposes only, into four classes depending on their contents and the nature of their movements. Size was not considered, as the number below 20 microns was negligible. Class I (total 47). This includes all amoobre in which definite red blood ~orpuscles were observed rolling about amongst the contents. These were diagnosed E. histolytica and formed 28'3 per cent of the total number of amoobre' found. Olass Il (total 2). All the amoobre placed in Olass II were actively progressive and all had clear pseudopodia. Some cases showed the presence of cysts of E. histolytica during convalescence, but. the majority were put into this class because the contents of the amoobre resembled red blood-corpuscles. This point will be elaborated shortly. ' Amoobre of this class formed 2'6 percent of the total numbers found. Olass III (total 28). Certain amoobre were distinguished only by the nature of their movements, which were definitely progressive and active; 68 per cent of the total amoobre were of this nature. Class IV (total 70). The remainder of the amoobre found, 42' per cent of the total, had none of the distinguishing features of E. histolytica, and therefore were classed separately. This classification, unscientific as it is, is based on features which are readily observable when examining fresh specimens under the microscope. It is,esseutial, however, that the specimens be fresh, and luckily there is seldom' difficulty in obtaining fresh specimens in military laboratories. Staining and cultural methods were used for a time both in 932 and 933, but were given up as impracticable for routine use where large numbers of ca&es are being dealt with simultaneously. The day is not long enough to devote time to such methods and at the same time make sure that the bacteriological diagnosis of each case is not being neglected. Yet without them some diagnosis must be made. At the moment, in our military laboratories the criterion ~f pathogenicity is the presence inside the amooba of ingested redblood-corpuscles. Such amoobre, the Olass I amoobre of this note, formed ol~ly 28'3 per cent of the total,numbers of amoobre found during 933,an< only suchamoobre were regarded as E. histolytica. Amoobic dysentery thus diagnosed fornied 6'5 per cent of the total dysentery in Quetta'in '93,3. As this, figure is somewhat lower than that commonly accepted'as'th~ percentage proportiori of amrebic dysentery, it seems likely that a number of amrebic cases,,,ere' missed, the reason being, 'in my

3 D. T. M. Large and O. K. Sarzkaran 305 OpInIOn, that it was often very difficult to make certain of the' fact of hrematophagy in cases showing amoobre otherwise resembling E. histolytica. In some cases. an almost impracticably prolonged search was necessary to find an amooba containing red blood-corpuscles amongst many without red blood-corpuscles, and in others the only evidence of hrematophagy was indefinite, owing to the effect of digestion on the ingested red blood~ corpuscles. Aa evidence of the difficulty of finding an amooba with contained red blood-corpuscles~ the two following cases are quoted. Case I.-Senior Medical Officer. A specimen received on the third day of disease' was found to contain amoobre, very active and progressive, pseudopodia blunt, clear,and as wide as the amoobre, Charcot-Leyden crystals present, and yet at least twenty amoobre were examined before one could be certain that an undoubted red blood-corpuscle was present in one of them. Subsequent to this, dozens of slides were examined and probably hundreds of amcebre, and yet only one other showed perfect red bloodcol;puscles among its contents. If this had not been a special case it is unlikely thathrernatophagy would have been observed. No bacteriological cause was found in this typical case of dysentery. Relapse occurred seven months later in spite of treatment. ' ' Case 2.-Captain H. Three years' history of dysentery treated in various hospitals with anti-dysenteric serum and salines. Special examination was given him as he was a frequent opponent on the golf links. First specimen showed am~bre and among them one of the following description: " Amooba 20 ft, fairly active and progressive. Pseudopodia clear, nucleus not visible, contents numerous, including, round yellowish bodies about 0 ft, large clear advancing pseudopodia, Charcot-Leyden crystals present." Second specimen on same day showed" arnooba streak-like in form and actively progressive, cy'toplasm yellowish in places." Third showed "amooba 20 ft, actively progressive, nucleus invisibie, contains fiv~ undamaged red blood-corpuscles: Numerous other amoobre." That is, a definite hrematophagous amceba was not found until the third specimen had been searched. Six microscopes were employed and six observers examined slides simultaneously. Obviously, therefore, if hrematophagy alone is,to be the standard of pathogenicity, the attention of 'the laboratory must be concentrated on the one case until it is found.,with regard to the effect of digestion on ingested red blood-corpuscles, the percentage of active amoobre diagnosed' as E. histolytica would ha"e been considerably higher if a somewhat broader view had been taken of what exactly constitutes hrematophagy. Nothing but definite undamaged red blood-corpuscles inside the amooba was accepted as evidence olthis. Cases frequently occurred, bowever, in which bodies of the size of red blood-corpuscles were found. These could not definitely be said to be red blood-corpuscles. owing to irregularity of; contour, or to slight difference in.colour.from the red blood-corpuscles outside the ~moobre; or the rounded 22.

4 306 Dysentery among Troops in Quetta 'bodies insiue the amoobre although of the right colour were perhaps larger or 'smaller than the normal red blood-corpuscles. There must, of course, be a. stage in the digestion of red blood-corpuscles inside the amooba' when they cease to be recognizable as such, but information as to the stage at which this occurs, or as to the appearances which this digestion produces in the red blood-corpuscles, is difficult to obtain. A few cases occurred here this year on which observations on these appearances have been made, and the notes made at the time on their index cards are as follows :- "September 28, 933. Case of Dr. H. Numerous red blood-corpuscles in specimen. Numerous active hyaline amoobre with few contents. These contained red blood-corpuscles similar to thos E3 outside the amoobre, but they also contained red blood-corpuscles apparently in process of digestion. These red blood-corpuscles were of all sizes less than normal. Their outlines were even and regular, and their colour was that of a red blood-corpuscle. Owing to their varying size and in spite of their colour they would have been taken for ingested oil globules, but for the fact of unaltered red blood-corpuscles both outside the amceba and inside it." "October 27, 983. Case No. 039, swarming with E. histolytica. Some contain numerous unaltered ted blood-~orpuscles, others show simply It yellow granular staining, while others show disintegrated red bloodcorpuscles as follows: (a) Irregularly-shaped particles of the colour of red blood-c,orpuscles, all less than seven microns in size. (b) Rounded bodies of the colour of.red blood-corpuscles and varying in si'ze from seven mi0rons down to about two microns. (c) Red blood-corpuscles of all sizes less than 'normal, with crenated edges." It is" obvious, therefore, that many of the amcebre placed in Class II because they contain bodies resembling red blood-corpuscles are in reality.hrematopha,gous amcebffi and belong really to Class I. It seems definite also that an amooba may be hrematophagous and yet show little niore than a yellow granular staining as evidence of this. The dictum, therefore, that no,amooba should be regarded as E. histolytica unless it contains red blood-corpusclt'ls might justitiably be widened somewhat so as to include evidenceo! hrematophagy, such as degenerated red blood-corpuscles ('?) or even yellow,stained areas in the cytoplasm of an amooba which is active and progressive. A wider view of what constitutes ingested red bloodcorpuscles would have brought our 28'S per cent of E. histolytica up to about 38'5 per cent of all amoobre, for the great majority of our Class II amcebrecontained bodies resembling red blood-corpuscles (7 out of 2). Hrematophagy alone as the standard, therefore. is not sufficient to define all pathogenic amoobre unless the laboratory is able, to concentrate on each individual case by examining specimen after specimen until it is found. Even then one may have to be content. with semi-digested red blood-corpuscles as evidence of this. Even the presence of degenerated red blood-.corpuscles, in an amoob;t :which progresses. actively.by the

5 D. T. M. Large and O. K. Sankaran 307 extrusion of clear pseudopodia would not, in my opinion, if adopted as a standard, have the effect of including an appreciable number of nonpathogenic amooboo. With regard to the non-hoomatopbagous amooboo which progress actively by means of throwing out clear pseudopodia (Class IH of this paper) there is a lack of agreement amongst recent writers as to the diagnostic value of two important. points generally. considered to appertain solely t,o E. histolytica, which otherwise might have given considerable aid. The American writers Toynbee Wight and Prince [2J have shown that E. coli also may have clear pseudopodia, and they believe its movements may be just as active as those of E. histolytica, One of them actually goes the length of stating that E. coli may ingest red blood-corpuscles, which leaves the ordinary man in despair as to the diagnosis of amooboo in general. Apparently 'notbing is peculiarly characteristic of E. histolytica, except perhaps its nucleus, and that cannot be examined properly except ill stained specimens. On the other hand there is the quotation from Wenyon given earlier in this paper,,. As regards the large amooboo from 5 to 20 microns or more, if they occur in dysenteric stools, and are very active, they are probably E. histolytica." This in my opinion is the attitude to adopt when treatment has to be considered. Only a protozoologist can say whether such amooboo actually are E. histolytica or not, and in the absence of a protozoologist it seems to be fairer to the patient to give him the benefit of the doubt, and regard such actively progressive amoobre as being of a pathogenic nature. In the Quetta cases in 933, 9' out of 28 Class III amooba:l occurred in dysenteric stools, and, therefore, if the writer's interpretation of Wenyon is correct, they were" probably" E. histolytica. If one grants this, the proportion of amoobic to other forms of dysentery would be raised from the figure 6'5 per cent based on hoomatophagy, to 2' per cent as a result of the inclusion of these active Class Il and Class III amceboo. This figure is somewhat higher than the all India figure from military laboratories (9'7 per cent in 932) but it.is.more in accordance with recent writings than the figure 6'5 per cent based on hoomatophagy alone. The amooboo found in the various classes were distributed amongst the different varieties o(dysente;lry and diarrhooa as shown herewith. Class I Class Il Class III Class IV Total Cases without amoobre amcebre. Bacillary dysentery Clinical dysentery Diarrhcea It will be seen that out of forty-seven hoomatophagous amooboo, no fewer than twenty-six were found in cases which showed evidence of bacillary infection either by the presence of a bacillus of dysentery or III the character of the exugate.. That j~, more than half of the cases of amoobic dysentery in 933'occurred in the form of a mixed infection.

6 308 Dysentery among Troops m '. Quetta PART II F. Relapses.-It is not easy to give a definition of what constitutes a relapse in dysentery. An attack due, for example, to B. dysenterice Flexner "X" may be followed shortly afterwards by another attack during which B. dysenterice Flexner "V" is isolated. Clinically this may be a relapse, bacteriologically it is not. Similarly with regard to time, an attack caused by B. dysenterice Flexner "V" may be followed in a few months by another attack due to the same organism. This may be a relapse, but there can be little proof that it is not a fresh infection. Another difficulty arises from the widely different incubation periods of bacillary and ammbic dysentery, so that the subject becomes very complex. While the incubation period of all forms of bacillary dysentery is probably within one week, the incubation period of ammbic dysentery may be anything from two weeks to two or three months, according to the experience of Walker and Sellards l3], who administered E. histolytica cysts to certain prisoners. Therefore, a clinical. relapse of dysentery two months after the first attack may possibly be an ammbic infection implanted at the same time as the bacillary infection which caused the first atta,ck. Such cases were, however, uncommon in 933, only one out of thirty-eight " relapses" within a period of three months showing E. histolytica in the second attack after an earlier bacillary.infection; During 933, as was to be expected, ammbic dysentery cases were more liable to a second attack of dysentery than non-ammbic cases. For example, of the 47 cases already mentioned, no less than 7, or 36' per cent, suffered a second attack within one year, while of 643 cases in which E. histolytica was not found, the number was 84, or 3 per cent. On the other hand, the great majority of cases in which second or multiple attacks occurred were not ammbic at all, owing to the low incidence of ammbic dysentery as compared with bacillary. During 933, 0 cases of dysentery had a second or multiple attack of dysentery or an admission to hospital for diarrhma shortly before or after their admission for dysentery. Of these ;- E. histolytica were found in.. E. histolytica cysts were found in.. Amrebre, Class Il; were found in. Amrebre, Class Ill, were found in.. But no amrebre at all were found in l ~ = 27 per cent... '" = 73 per cent., Another point of importance from which it is possible that an inference may be drawn is the length of time between the attacks in cases of double or multiple attacks of dysentery. The great majority of second attacks occurred within three months of the first, and, of these, most occurred within one month after admission for the first attack. For example :- Recurrence in one month. Recurrence in two months.. Recurrence in three months ,

7 D. T. M. Large and O. K. Sankaran 309 These figures refer to cases in which an attack of dysentery was followed by a second attack of dysentery, and if one adds to these those cases in which one of the attacks was apparently only diarrhcea a similar table may be prepared as follows :- TABLE. DYSENTERY RELAPSES, 933. st attack 2nd attack Within Between month and 3 months Dysentery bacillus followed by dysentery exudate 4 2 Dysentery exudate Dysentery bacillus Dysan tery bacil! us Dysentery exudate E. histolytica Dysentery exudate E. histolytica Dysentery bacillus E. histoly tica E. histolytica Diarrhrea Dysentery exudate Diarrhrea Dysentery bacillus Diarrhrea " " " dysentery bacillus 5 " dysentery bacillus " (same type) 3 3 (a) dysentery bacillus " (different type) 3 3 " dysentery exudate 5 (b) 2 dysentery exudate " E. histolytica " dysentery bacillus 2 " E. histolytica 2 E~ histolytica 24 4 DYSENTERY-DIARRH<EA RELAPSES, 933. i.e., dysentery one attack, diarrhrea in the other. followed by diarrhrea.. E. histolytica 2 " diarrbrea 5 (c) 2 " dysentery exudate 5 (d) 3 diarrhrea 9 3 " dysentery bacillus Betweeri 3 and 2 months 4 5 (a) (a) Associated with one Class III amreba. (b)" two cases showinge. hystolytica cysts. (cr "." one case showing Class Il amreba. (d) one Class Il amreba and one E. histolytica cysts. The figures ehow number of cases. Double attack of dysentery or an attack of dysentery and of diarrhrea in 933. Within one month two months' three four five six seven eight nine '" ten eleven twelve (a) (b) (c) 0 It appears reasonable to doubt, from the large numbers of readmissions within one month, if the treatment of the initial attack had been sufficient. The numbers of such cases are not inconsiderable, for 6'6 per cent of cases were readmitted within one month, and a total of 0 per cent within three months. When one comes to consider the bacteriological findings in the double or multiple attacks in each individual, one is led into difficulty at once. The table shows the laboratory findings in all cases in which more than 4 (a) 2 2 3

8 30 I!ys'entery among Troops in Q'Ueita. one attack of dysentery occiirred in 933, or in which an attack of dysentery was followed or preceded by an attack oldiarrhooa. Those in which the two attacks occurred within one month are ShOWli in column 3, while columns 4 and 5 show those in which the subsequent attack occurred between one and three months, and between three and twelve months respectively after the first attack. l'he extraordinarily varied nature of the laboratory findings is evidenced by the complexity of this table. Herein lies the difficulty, for in the majority of these cases it is impossible to say that relapse has occurred, although there is little doubt that the clinician and the patient would regard a second attack within two or three months of the first as being likely to be of the nature of a relapse. In only a very small minority of the cases were the findings of the first attack repeated in the second attack, and in only one case was a finding of E. histolytica in the first attack followed by a finding of E. histolytica in the second attack. The laboratory findings in the non-amoobic cases were so varied that comment on them can only be of a speculatory nature. Only seven showed a finding of the same type of dysentery bacillus in the two attacks, and in these even there can be no proof that fresh infection had not occurred. The majority of the cases showed no apparent continuity of infection, and all that can be said of them is that they had two or more attacks within a year. Whether this was because they were more exposed to infection than normal, or more susceptible than normal, or whether the second attack was a relapse of the first in spite of the different laboratory findings, it is impossible to say. Several cases which were closely followed throughout the year showed the most extraordinary findings; for example :- Case B. showed B. dysenteri~ Flexner type 70 in June, B. dysenterice Flexner type 88 in July, indefinite exudate in August, and a return to B. dysenterice type 70 in September. Case C. J. showed B. dysenterim Sonne in June, another attack due to B. dysenterim" Sonne in July, B. dysenterim Flexner (Andrewes type) in August and in~efinite exudate in September. Case H. showed B. dysenterice Flexner (Andrewes) in May, bacillary exudate in J~~ne, indefinite exudate in September, and a return to B. dysenterim Flexner (Andrewes) in October. These case:~ do not show the continuity of infection one might expect in such frequent relapses. It appears almost as if a single organism were responsible" in each case, appearing in a different form according to its environment at the time. PART II G. MIXED INFECTIONS. Those mixed infections, in which a. bacillary and an amoobic infection were acquired at the same time, so that a primary bacillary attack was followed some weeks later by an amoobic attacl<, were rare, only one out of forty-seven cases of amoobic dysentery in 933 giving evidence of such a possibility.

9 D. T. M.Large and O. K. Bankaran 3 The remainder of the cases, 29 in number, in which evidence of bacillary dysentery and of amoobic dysentery was discovered in the one attack, may be divided into two: () Those in whom hrematophagous amoobre were discovered in an. attack of dysentery during the course of which a bacillary exudate was noted. These numbered 3.. (2) Those in whom definite proof of the mixed infection was afforded by the isolation of a dysentery bacillus in the course of an. attack in which also hrematophagous amoobre were found. These were,6 in number. Altogether 30 cases of mixed infection ofamoobic and bacillary dysentery occurred in 690 cases, a percentage of 4'3. The association in one illness of the causative agents of amoobic and bacillary dysentery, where no previous disability was noted by the medical officer, probably means that the bacillary infection took place. during the incubation period of the E. histolytica, and probably that the developing amoobic infection gave. rise to a,n increased susceptibility to any bacillary infection which happened to be prevalent. This as a matter of fact appears to have happened in more than half of the amoobic cases in 933, for no fewer than 62 per cent of the cases in which hrerriatophagous amoobre were found showed in addition evidence of a bacillary infection, either by the isolation of a dysentery bacillus or by the finding of a bacillary exudate. The amoobre were usually found on the second or third day of the disease and seldom occurred in the bacillary exudate itself, possibly I think because such exudates were. not searched as thoroughly, and partly certainly because an amooba does not stand out so clearly in a preponderance.of pus cells and is therefore liable to be missed.. The organisms associated with these hrematophagous amoobre were as follows: B. dysentel'ice Flexner (type 88 Boyd) 6 cases; B. dysentel'ice Sonne, B. dysenter'ice Flexner (type 70 Boyd), B. dysenterice Flexner 2 cases each; B. dysenterice Shiga, B. dysenterice, Schmitz and B. dysenterice Flexner (inagglutinable) case each. Such are the mixed infections in which definite E. histolytica were associated with bacillary dysentery (4'3 per cent). A further 8 cases occurred in which the bacillary infection was accompanied by the presence of Class II and Class III amoobre, so that the. maximum number of cases in which it could be said that a possible mixed infection had occurred was 6'9 per cent.. SUMMARY. () One hundred and sixty-six cases suspected of dysentery in Quetta were found to contain amoobre of a size similar to that of E. histolytica. These were arranged into four classes, depending on the characters of the amoobre in fresh specimens. Class. The amooba contained undamaged red blood-corpuscles, 28'3 per cent. _ Class n.. The amooba was active and progressive with clear pseudopodia. It contained bodies resembling red blood-corpuscles, or E. his tolytica cysts dev~loped during convalescence of the patient, 2'6 per cent.

10 32 Dysentery among Troops in. Quetta Class Ill. The amooba was active and progressive, 6 8 per cent. Class IV. The amooba showed none of the above characteristics normally found in E. histolytica, 42 per cent. Cases showing hrematophagous amcebffi, i.e. Class I, formed 6 5 per cent of the total dysentery. If Class II amoobffi are accepted as E~ histolytica, the proportion of amoobic dysentery would be raised to g S per cent. It is considered that active and progressive amoobffi occurring in dysenteric stools should in the interests of the patient be regarded with great suspicion, if not actually treated as E. histolytica. Their inclusion as pathogenic amoobre would have raised the proportion of amoobic to other forms of dysentery to 2 per cent. (2) Twenty-six out of forty-seven cases showing definite E. histolytica, also showed evidence oi bacillary infection. That is, amoobic dysentery occurred more frequently in association with bacillary dysentery than asa separate entity. (3) Of the total dysentery, mixed infections of bacillary and amoobic dysentery occurred in 4 3 per cent of the cases as a minimum figure and in 6 9 per cent of the cases if all the actively progressive amoobffi described were considered pathogenic. In the majority of cases the evidence suggested that developing or symptomless amoobic dysentery may have been a predisposing cause of the onset of the bacillary infection. (4) Definite relapses of dysentery in which the laboratory findings in the two attacks were the same, were very few. Out of 0 cases of double or multiple attacks within one year, seven showed the same organism in the two attacks, one showed E. histolytica in the two attacks. ' In the remainder of the cases the causative organism was not isolated in one of the attacks, in spite of careful and efficient laboratory examination. It is impossible to say whether such cases were relapses or fresh infections. They may have been of the nature of a chronic infection with exacerbations, in which it is always difficult to isolate the causative organism. (5) Double or multiple attacks of dysentery occurring within a space of one year showed E. histolytica in 7 per cent of cases and active progessive amoobffi in a further 0 per cent of cases. The majority of double or multiple attacks were bacillary in origin.. REFERENCES. [lj WENYON, C. M. (926). Textbook "Protozoology." [2J TOYNBEE WIGHT, T. H., and PRINCE, L. H. (927). Amer. Journ. Trop. Med., v, 287. [3J WALKER, El: L., and 'SELLARDS, A. W. (93). Philippine Journ. Sci. (B), viii, 253. ACKNOWLEDGMENTS. Thanks are due to Major-General J. F. Martin, C.M.G., C.B.E., K.H.S., for permission to forward this paper for publication, and to Lieutenant Colonel G. R Lynn, D.S.O., alld Majors R. F. Bridges, J. B. Molony, O.B.E., and to J. S. K. Boyd, who strongly criticized certain aspects of its different sections while in the rough; and to my assistant C. J. D. Burghall, I.M.D., without whose valuable help the work could not have been performed.