322 MANUAL OF BACTERIOLOGY. 



Sterilized; the hands of the attendants should be carefully 

 disinfected and all food should be cooked. Although com- 

 moner 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 neces- 

 sary, 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 soHd particles 

 which may be found in the discharges from the intestines 

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

 ner, 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 parallel groups, as already described. If 

 comma-shaped bacilli are thus found, a strong probabiHty 

 is created that the disease is Asiatic cholera. The motility of 

 the organisms can be determined by examination in the hang- 

 ing-drop. It is to be remembered that spirilla of various forms 

 are common in the normal mouth, and may appear in the 

 stools (see pages 141 and 226). 



The diagnosis should be confirmed by the use of culture- 

 methods. Using the small, semisolid particles from the 

 intestinal discharges, gelatin plates in the usual three dilu- 



