194 



bacteria without apparent injury to themselves. The flora and 

 condition of the gastro-intestinal tract, the amount and virulence of 

 the infection, and other conditions ("Y" and "Z" of Pettenkofer) 

 play an important role in the production of these diseases. 



The following references from the literature give the instances in 

 which the B. typJii murium, or similar rat viruses, have been held 

 responsible for the disease in man: 



Trommsdorff a carefully studied 13 suspected cases near Munich in 

 early May, 1903. Nine of these came into direct contact with the 

 virus, three ate and associated with these, and the remaining one 

 only smelled of the virus. One died from vomiting and severe 

 diarrhea. The illness, which set in usually two days after contact 

 with the virus, was for the most part simple diarrhea of two to seven 

 days' duration (two to eight stools daily); in only three or four 

 cases was there vomiting. The one fatal case seemed due to a con- 

 fusing chain of circumstances, gross dietetic and alcoholic excesses 

 in a weak, emaciated, presumably phthisical man whose three 

 brothers had died of phthisis. One man, case No. 2 in the table, 

 known to have eaten three pieces of infected bread, suffered only 

 with a mild diarrhea. 



In all cases errors of diet could be proven, and diarrhea was not 

 uncommon at that season. The same physician attended during 

 this period ten other cases of similar diarrhea in the vicinity having 

 nothing to do with rat virus. The stools, however, did not have 

 the same pathogenicity for mice, guinea pigs, or rabbits. 



Trommsdorff specially points out the fact that the bacillus of 

 mouse typhoid can multiply vigorously in the human intestine. It 

 demands greater caution in the application of the cultures and more 

 careful supervision over their use. 



Finally, attention is invited to the fact that, contrary to the usual 

 custom, the cultures of rat virus here used had been grown on milk, 

 which might account for the increased virulence. 



a Trommsdorff, R.: Ueber Pathogenitat des Lofflerschen Maustyphusbazillus beim 

 Menschen. Munch, med. Woch., vol. 50, 1903, p. 2092. 



