PROPHYLAXIS. 457 



toms are not produced in animals by feeding the 

 organisms. 



The stools of the patient are the only known 



11 Oil JlllH 



source of the organism and it continues to be ex- infection 

 creted during convalescence. Latent or chronic 

 cases are a source of danger to a community. Al- 

 though the conditions outside the body are not 

 favorable for the growth of the organism, it may 

 remain living and virulent for several months. The 

 methods of infection appear identical with those 

 in typhoid. Water infection seems certain, and 

 indirect transmission is accomplished by contact 

 with the discharges. The best examples of contact 

 infection are found in institutional epidemics. 



The first essential for prophylaxis is correct di- prophylaxis 

 agnosis, for which the agglutination test and bac- 

 teriologic examination of the stools are essential. 

 Disinfection and other precautions should be prac- 

 ticed as rigidly as in typhoid. The patient should 

 not be discharged until the stools are free from 

 dysentery bacilli. 



Poorly nourished individuals are particularly 

 susceptible to infection, and among them the mor- 

 tality is high. The disease is most common among 

 young children, old people, and those who are con- 

 fined in institutions. The conditions in Japan, 

 however, where from June to December of one year 

 nearly 90,000 were attacked, and in Germany, 

 where severe epidemics occur in industrial com- 

 munities, indicate that susceptibility is quite gen- 

 eral. Digestive disturbances and enteritis from 

 other causes are said to be predisposing factors. 

 The normal serums of man and animals have very 

 little bactericidal power for djsentery bacilli. 



