232 THE CARRIAGE OF TYPHOID FEVER BY FLIES 



disclose a considerable percentage of " carriers " who are, un- 

 knowingly, distributors of the typhoid bacillus. 



The dissemination of 'I^i-hoid Fever, epidemiological 



AND circumstantial EVIDENCE. 



In (li.scussing the possible methods of the dis.semination of the 

 typhoid bacillus in the report on the prevalence of typhoid fever 

 in the District of Columbia, Kober (1895) states: "The agency 

 of flies and other insects in carrying the germs from box-privies 

 and other receptacles from typhoid stools to the food cannot be 

 ignored " ; and in discussing certain special cases he says : " There 

 is abundant evidence of unlawful surface pollution... and as the 

 germs find a suitable soil in such surroundings it is possible that 

 the flies, which abound wherever surface pollution exists, may carry 

 the germs into the houses and contaminate the food." Later he 

 states : "A large percentage of the cases occurred in houses supplied 

 with box-privies which, apart from being an important cause in 

 soil pollution, are believed to be otherwise instrumental in the 

 dissemination of germs chiefly through the ugency of flies." 



There is a very large amount of testimony given as to the role 

 played by flies in the spread of enteric in military stations and 

 camps, and especially during the two wars — the Spanish-American 

 and the Boer War. All the conditions most favourable for the 

 dissemination of the bacilli by flies were, and in many military 

 stations are still, present ; open latrines or filth-trenches accessible 

 to flies on the one hand and on the other the men's food within a 

 short distance from the latrines. I cannot do better than quote 

 the evidence in the words of the witnesses and allow it to speak 

 for itself 



Vaughan, a member of the United States Army Typhoid 

 Commission of 1898, states : 



" My reasons for believing that flies were active in the 

 dissemination of typhoid fever may be stated as follows : 



" (a) Flies swarmed over infected faecal matter in the pits 



and then visited and fed upon the food prepared for the 



soldiers in the mess-tents. In some instances where lime had 



