8l6 MICROBIOLOGY OF DISEASES OF MAN AND DOMESTIC ANIMALS 



DYSENTERY* 

 Bacterium dysenteric^ 



Two chief types of dysentery are known, one due to a protozoon, 

 Entam&ba histolytica; the other due to a bacterium Bact. dysenteries. 

 Only the latter is here dealt with. 



Acute dysentery in an epidemic form is found chiefly in Asia, some- 

 times in Europe and in the Philippines. In this country occasional 

 small epidemics and certain types of summer diarrhoeas of infants have 

 been shown to be due to Bact. dysenteries. The disease occurs naturally 

 only in man. 



Dysentery is an intestinal disorder usually acute and, in its epidemic 

 form, very severe, marked by a flux in which there is the frequent pass- 

 age of blood and mucus with severe tenesmus and pain in the abdomen. 

 The fever accompanying this may reach 104 and in the severe cases 

 delirium and death may result. In Japanese epidemics the fatality has 

 reached 25 per cent or more. 



The pathological findings are most marked in the intestine where 

 the mucosa is swollen and hyperaemic, with more or less haemorrhage 

 and extensive necrosis. 



Shiga in 1898 discovered a bacterium in the stools of persons suffer- 

 ing from the disease and the organism was agglutinated by the blood 

 serum of the patients. He found the same organism repeatedly in a 

 considerable number of cases. 



The results of many other investigations have demonstrated the 

 presence of several forms conforming in general to the type described 

 by Shiga but showing some difference in fermentation properties; these 

 are sometimes known as para- or pseudo-dysentery bacteria. The 

 most important of these are the Flexner, Strong, and Hiss' and Russel's 

 "Y" types. 



The constant presence of the organism in the epidemic type and the 

 fact of agglutination leave little doubt as to the etiological relation. A 

 criminal fed with a pure culture of Shiga's organism developed the 

 typical disease. 



The organism can occasionally be isolated in almost pure culture 

 from bits of mucus in the stool. Endows and other special media may 



Prepared by Edward Fidlar. 



