f 



. PATHOGENIC BACTERIA. 321 



isms may, however, be carried by other articles of food, 

 and may be conveyed occasionally through contaminated 

 clothing and bedding, and probably by flies. The excreta 

 and bedding should be thoroughly sterilized, the hands of 

 the attendants must be carefully disinfected. Although 

 commoner in the summer-time, epidemics of cholera have 

 been known to occur in the winter. 



Bacteriological Diagnosis of Cholera. When cases sus- 

 pected of being cholera appear in a community, it becomes 

 a matter of the utmost importance to determine the exact 

 nature of the disease in order that it may not become 

 epidemic. One of the first occasions when bacteriological 

 methods were put into practice in the diagnosis of cholera 

 was at the time of the appearance of that disease in the 

 Port of New York in 1887. 



According to Koch, the diagnosis may be made in twenty- 

 four hours or less. It is important to obtain the discharges 

 from the intestines as early in the course of the disease as 

 possible, and while they are perfectly fresh. It may be 

 necessary, however, to examine the moist dejecta on the 

 linen or clothing, when no other material is available. 



In the first place, one of the small, partly-solid particles 

 which may be found in the discharges from the intestines 

 should be smeared upon a cover-glass, fixed in the usual 

 manner, stained with one of the aniline dyes, and examined 

 with the microscope. If taken early in the disease, the 

 comma bacilli may be present in large numbers, and they 

 are likely to be arranged in more or less parallel groups 

 (see above). If comma-shaped bacilli are thus found, a 

 strong probability is created that the disease is Asiatic 

 cholera. The motility of the organisms can be determined 

 by examination in the hanging-drop. It is to be remem- 

 bered that spirilla of various forms are common in the 

 normal mouth, and may appear in the stools (see pages 

 152 and 228). 



