REVIEW — TROPICAL MEDICINE, ETC. 51 



demonstrated can be explained logically by the theory of " latent infectious," but only, as we have stated in a Dysentery — 

 previous report, "by the fact that the non-pathogenic E. coli is the organism present in these cases instead of the contimied 



pathogenic E. dijsenterke." 



Dr. Wenyon, working in Khartoum at cases of all kinds in the Military Hospital, found 

 that in the great majority E. coli or its cysts were present. These cysts were found in 

 recently passed fseces, and he has shown' that in mice and monkeys the formation of similar 

 cysts commences in the cscum. In cases of dysentery these cysts of E. coli were also present, 

 while the small cysts of E. histolytica were not seen. Further reference to this work will 

 be found in Dr. Wenyon's report. 



Birt^ has worked at South African dysentery. He isolated Shiga's bacillus in 26 out of 55 

 cases examined. Amoebae were only found once. The method of examination adopted may be 

 detailed. Wash a fragment of blood-stained mucus in sterile salt solution. Transfer to a 

 second lot and shake vigorously. Place on Drigalski-Conradi medium, taurocholate neutral 

 red, crystal violet, lactose agar, lactose litmus agar or ordinary agar (+ 25 Eyre's scale). 

 Next day transfer more delicate colonies to Doer's modifications of Barsikow's medium 

 consisting of nutrose, mannite, litmus and water. Shiga's bacillus leaves this unchanged. 

 The colon bacillus curdles it and turns it pink. Sub-cultivate on agar and, if Gram-negative 

 rods obtained, put up in sedimentation tubes with the patient's serum, normal human serum 

 and the serum of an animal immunised with Shiga's serum. 



Highest dilution noted for clumping was 1 in 600, the usual 1 in 20-50. The 

 agglutinating power was not of long duration. 



Blackham' has written a very excellent paper on tropical dysentery, chiefly from the 

 bacteriological standpoint, at the close of which he states that the various strains of 

 B. dysenterim isolated by Shiga, Plexner, Vaillard, Harris, Firth, etc., are simply varieties 

 of the same organism. There are also non-pathogenic pseudo-dysentery bacilli which act 

 on carbohydrates unaffected by Shiga's and the other pathogenic bacilli, and fail to produce 

 enteritis in animals. The dysentery organisms will live on clothing for at least three weeks 

 and are said to maintain their virulence in damp soil for months. Spread on bread crumbs 

 or similar articles of food, they survive for about a week. They are not very readily 

 destroyed by heat or by weak solutions of perchloride of mercury or the higher phenols. 

 The Widal reaction is often poorly marked, but is of some value, and can usually be 

 obtained within two weeks of the onset of symptoms. 



The character of the stools alone is not to be considered as a test of the presence or 

 absence of dysentery. A group of maladies of varying severity come under the term 

 dysentery, ranging from the acute dysentery of armies to the simple infective diarrhoea of 

 infants and adults. 



Blackham believes that "in the tropics all cases of diarrhoea should be treated with 

 the same precautions as if they were manifest cases of dysentery, and in hospital should 

 invariably be isolated and their stools sterilised in some simple form of steriliser or 

 by means of disinfectants." 



Duncan,'* in a useful paper, describes the different types of stool met with in cases of 

 dysentery, and concludes by considering the indications obtainable from the different 

 appearances of the stools in dysentery as regard prognosis. 



1. A good result can be foreshadowed in those cases in which are passed mucus with 

 minute faecal lumps, stained or not with blood, and in which the blood and mucus 

 disappear ; the ordinary faecal characters will soon manifest themselves. 



2. The prognosis is of evil omen : (a) according to Sir Joseph Fayrer, in the cases in 

 which pulpy stools without blood or mucus are passed ; (6) where fluid faecal matter is from 

 time to time passed throughout the illness, the prognosis is unfavourable, inasmuch as these 

 characters of the stools show the disease to be extensive, and affecting chiefly the upper 

 part of the large, as well as in some cases part of the small, intestine ; (c) where the stools, 

 in conjunction with the symptoms that are laid down as characterising the true amcebic 

 dysentery, are present, the prognosis is again unfavourable on account of the high mortality 

 that is said to attend this form of the disease ; (d) the prognosis is of the worst possible 



' Archiv. fill- Protistenkuiide, Suppl. I., 1907. 



^ Birt, C. (March 31st, 1906), " Dysentery in South Africa." Lancet, p. 904, Vol. I. 



■■■ Blackham, R. .T. (December Ist, 190G), "Tropical Dysentery." Lancet, p. 1493, Vol. II. 



* Duncan, A. (May 2nd, 1904), " The Stools of Dysentery and the Prognostic Indications derivable from 

 them." Journal of Tropical Medicine, Vol. VII. 



