32O MANUAL OF BACTERIOLOGY. 



has advised the use of this reaction as a means of diagnosis, 

 inasmuch as the spirilla which apparently resemble the 

 spirillum of cholera, but are in reality different from it, do 

 not become disintegrated when they are introduced in the 

 peritoneum of an animal made immune to the spirillum of 

 cholera. It has been shown also that blood from animals 

 made immune to cholera has an agglutinating action upon 

 the spirillum of cholera like that seen when the blood-serum 

 of cases of typhoid fever is mixed with living typhoid 

 bacilli. 



The outlook is encouraging for the production of a safe method for 

 immunizing healthy persons from cholera during an epidemic. 1 



Although a positive demonstration that the spirillum of 

 Koch is the cause of cholera is lacking, as far as the exact 

 reproduction of the disease in animals is concerned, the 

 necessary proof has been supplied by the accidental or 

 intentional infection of laboratory investigators who were 

 working with cholera, which has happened on several occa- 

 sions. 



Bacteriological investigations of the victims of cholera 

 have shown that the spirilla of cholera are present in very 

 large numbers in the watery contents of the intestine, espe- 

 cially early in the disease. They appear in the lumina of 

 the glands, and they may be seen underneath the epithelial 

 cells. They may occur in the matters vomited. They 

 usually are not found widely spread through the organs of 

 the body. It is probable that the symptoms of the disease 

 result from poisonous substances produced by the spirilla 

 or contained in them. 



The infectious element in cholera is usually transmitted 

 through water, and numerous epidemics have been studied 

 where the infection was traced to drinking-water, and the 

 origin of the contamination was discovered. The organ- 



1 Strong, American Medicine, Aug. 15, 19x53. 



