CHOLERA 63 



vidual may find their way into the mouth of another, or many gen- 

 erations of bacilli may lie between the two subjects. In all instances, 

 the connection is sure and certain. This disease spreads in no other 

 way. The only infected discharges from the cholera patient are those 

 that come from the alimentary canal. The vomited matter may con- 

 tain virulent bacilli but this is rarely the case on account of the great 

 susceptibility of the organism to acid solutions. Practically the only 

 infectious discharge is the stool. Among filthy people the stool may 

 go quite directly to the mouth by the hands. Mothers often infect 

 their children in this way and sometimes it is transferred from child 

 to parent. 



This contact infection is illustrated in the voyage of the Carlo R. 

 which sailed from Naples, Aug. 1, 1893, for Brazil, with 1,472 steer- 

 age passengers. The ship's water was not infected. On the outward 

 trip cholera appeared. On reaching South America the vessel was 

 not permitted to dock and was compelled to return. The double 

 voyage occupied two months and during this time there were 141 

 deaths among the steerage passengers. Scarcely less direct is the 

 transference from soiled clothing or bedding or when the infected 

 stools are deposited on fruits and plants which are subsequently eaten. 

 The less cleanly people are, the more liable to harbor this disease. 



Before the discovery of the bacillus, Pettenkoffer had observed 

 that, in its European visitations, this infection spared certain localities. 

 These were relatively clean places, such as would not afford oppor- 

 tunity for contact infection. The great outbreaks, such as that at 

 Hamburg in 1892, are due to infection of the general water-supply. 

 At that time Hamburg used the unfiltered water from the Elbe. At 

 first there were a few cases among those employed about the wharves. 

 Finally the pollution extended up the river and reached the city 

 water-supply. The first case was recognized early in August and the 

 explosion came on the 20th of the same month and by the 31st the 

 number of new cases per day reached one thousand. Hamburg and 

 Altoona are one city, but separated administratively. On one side of 

 the street the houses are in Hamburg and on the other in Altoona. 

 The latter had a separate and uninfected water-supply and was free 

 from the disease except among those who drank from the Hamburg 

 water. 



