ASIATIC CHOLERA AND THE CHOLERA ORGANISM 587 



pandemic proportions and sweeping over almost the entire earth. ^ Five 

 separate cholera epidemics of appaUing magnitude occurred during 

 the nineteenth century alone; several of these, spreading from India to 

 Asia Minor, Egypt, Russia, and the countries of Central Europe, reached 

 even to North and South America. The last great epidemic began about 

 1883, traveled gradually westward, and in 1892 reached Germany where 

 it appeared with especial virulence in Hamburg, and thence, fol- 

 lowing the highways of ocean commerce, entered America and Africa. 

 During this epidemic in Russia alone 800,000 people fell victims to the 

 disease. 



In man the disease is contracted by ingestion of cholera organisms 

 with water, food, or any contaminated material. The disease is essen- 

 tially an intestinal one. The bacteria, very sensitive to an acid reaction, 

 may often, if in small numbers, be checked by the normal gastric secre- 

 tions. Having once passed into the intestine, however, they proliferate 

 rapidly, often completely outgrowing the norma! intestinal flora. Fatal 

 cases, at autopsy, show extreme congestion of the intestinal walls. 

 Occasionally ecchymosis and localized necrosis of the mucosa may be 

 present and swelling of the solitary lymph-follicles and Peyer's 

 patches. Microscopically the cholera spirilla may be seen to have 

 penetrated the mucosa and to lie within its deepest layers close 

 to the submucosa. The most marked changes usually take place 

 in the lower half of the small intestine. The intestines are filled 

 with the characteristically fluid, slightly bloody, or "rice-water" 

 stools, from which often pure cultures of the cholera vibrio can 

 be grown. The microorganisms can be cultivated only from the 

 intestines and their contents, and the parenchymatous degenera- 

 tions taking place in other organs must be interpreted as being 

 purely of toxic origin. 



In animals, cholera never appears as a spontaneous disease. Nikati 

 and Rietsch ^ have succeeded in producing a fatal disease in guinea-pigs 

 by opening the peritoneum and injecting cholera .spirilla directly into 

 the duodenum. Koch ' succeeded in producing a fatal cholera-hke 

 disease in animals by introducing infected water into the stomach 

 through a catheter after neutrahzation of the gastric juice with sodium 

 carbonate. At the same time, he administered opium to prevent active 

 peristalsis. A method of infection more closely analogous to the infec- 



^Hirsch, "Handb. d. histor.-geogr. Path.," 1881. 

 ^ Nikati und Rietsch, Deut. med. Woch., 1884. 

 2 Koch, Deut. med. Woch., 1885. 



