i826 



THE DYSENTERIES 



Definition. — Amoebic dysentery is an acute or chronic specific 

 disease of the intestine, caused most commonly by Loeschia 

 histolytica Schaudinn, 1903, and possibly by other species. These 

 amoebae enter the body with food or water, and produce colitis, 

 rectitis, and enteritis, characterized by the passage of frequent 

 motions, which generally contain blood and mucus, and are asso- 

 ciated with abdominal pain and tenesmus. At times they also 

 produce abscesses in the liver and other parts of the body. 



History. — In i860 Lambl noticed amoebae in the motions of a 

 child suffering from diarrhoea, and in 1870 Lewis found the same 

 organisms in the motions of cholera patients; while Loesch, in 1875, 

 gave a careful description of certain amoebae which he found in the 

 motions of a man suffering from chronic diarrhoea. Loesch' s 

 drawing signifies that he saw the organism which we call now 

 Loeschia histolytica. Further, he found that solutions of quinine 

 of a strength of i in 5,000, when injected per rectum, temporarily 

 benefited his patient, who, however, subsequently died of pneu- 

 monia, when a post-mortem revealed that the bowels were ulcer- 

 ated. Loesch was able to infect dogs; but, on the other hand, 

 Grassi, and later Cunningham and Lewis, showed that the motions 

 of healthy people also contained amoebae. Koch, in 1883, found 

 amoebae in the ulcers in cases of dysentery in Egypt, and Kartulis 

 began a series of investigations, which finally ended by his defining 

 the types of dysentery as ' endemic,' due to amoebae, and 

 ' epidemic,' due to bacteria. In 1891 Councilman and Lafleur 

 introduced the term ' amoebic dysentery,' and Quincke, Roos, 

 Vivaldi, and many others published experimental researches on the 

 infection of animals by amoebae and the production of dysentery. 



In the meanwhile a prolonged discussion took place, some 

 observers denying, and others asserting, the pathogenicity of the 

 amoebae. Kruse and Pasquale were the first to throw light upon 

 this difference of opinion by suggesting that both theories might be 

 correct, and that there might be two species of amoebae, one patho- 

 genic and the other harmless; but this was not finally settled until 

 the researches of Casagrandi and Barbagallo, together with those 

 of Jiirgens, were confirmed and greatly extended by Schaudinn, 

 who showed that there were two forms of amoebae quite distinct 

 from one another — viz., a Loeschia coli Loesch, which was harm- 

 less, and another, L. histolytica Schaudinn, which was the true 

 cause of entamoebic dysentery. 



During recent years the labours of Hartmann, Whitmore, Wenyon, 

 Fantham and Porter, Dobell and others, have proved that the 

 amoeba which most commonly causes dysentery is L. histolytica, 

 and that the other forms of amoebae described in dysentery by 

 Viereck (L. tetragena) and other observers are different stages of 

 this amoeba, the cysts of which can be carried by domestic flies. 



Climatology. — Amoebic dysentery is found throughout the 

 tropical world, and also occurs in the Temperate Zone. In general 

 terms it may be stated that amoebic dysentery is common in 



