690 TYPHUS FEVER 



intermediate host, as the bite of the louse is especially infective 

 from the fifth to the seventh day after feeding. It has been 

 known that children under ten years are apparently less 

 susceptible to typhus than older individuals, and Nicolle has 

 made the interesting observation that when a family is attacked, 

 young children, while apparently well, may really suffer from 

 slight rise of temperature. This condition is probably an 

 abortive attack of the fever, as the blood in such cases is 

 infective for monkeys. Such abortive cases may play a part 

 in the dissemination of an epidemic. Nicolle's results have 

 found confirmation in similar work by Andersen and Goldberger, 

 and by Ricketts and Wilder in America. These observers were 

 dealing with a fever known in Mexico as tabardillo, a con- 

 dition probably identical with the typhus of the Old World. 



