838 PATHOGENIC MICROORGANISMS 



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 grad- 

 ually westward, and in 1892 reached Germany where it appeared 

 with especial virulence in Hamburg, and thence, following the high- 

 ways of ocean commerce, entered America and Africa. During this 

 epidemic in Russia alone 800,000 people fell victims to the disease. 



An important epidemiological fact is the existence of certain 

 endemic foci where cholera is always going on and from which 

 epidemics and pandemics originate. The chief endemic focus 

 seems to be located in lower Burmah, and it is, as yet, an 

 unsolved puzzle as to why the disease should remain smouldering 

 in such regions and spread widely only at certain periods, five, ten 

 or more years apart. During recent years important epidemics 

 have occurred between the years 1879 and 1910. In 1879 an 

 epidemic spread to Europe through Egypt and this outbreak is 

 notable because in 1883 in Egypt, Koch, 11 as head of the German 

 Cholera Commission, isolated the cholera spirillum. In 1891 

 another great epidemic, originating in India, is stated by Cas- 

 tellani as having started on the occasion of a bathing festival 

 held on the Ganges. It spread among pilgrims and reached Europe 

 in 1892, appearing with particular virulence in Hamburg. From 

 there it spread to America and Africa by ocean commerce. 

 During this epidemic it is said that 800,000 people fell victims 

 in Russia alone. Violle records that in 1908, 1909 and 1910 

 there were a series of epidemics in Russia. In 1908 there were 

 about 30,000 cases with 14,000 deaths; in 1909, there were 21,000 

 cases with 9,700 deaths, and in 1909 to 1910 there were 130,000 

 deaths. During the Balkan War in 1912 cholera appeared 

 among the armies. During the late war there were cases of cholera 

 in Galicia in the Austrian Army, and there were outbreaks in Bul- 

 garia, Greece and Turkey, and in Mesopotamia. 



The prevalence of cholera as an important epidemic disease may 

 be estimated by the following chart of cholera epidemics of the 

 last hundred years which is taken from Violle 's recent work on 

 cholera (1918) to which numerous references have been made. 



The disease always originates from the dejecta of cholera patients 

 and carriers. At times of epidemic, infection of the water and 



11 Koch, Deut. med. Woch., 1883 and 1884. 



