TYPHOID FEVER I4I 



Station over 60 men who had enteric fever before the days when 

 convalescents were examined to eliminate 'carriers.' An ex- 

 amination of these men has been recently begun, and already 

 I have found two men who have been carriers since 1906, so 

 that it cannot be said that anything more than usual has been 

 done to prevent direct infection. The Mhow water supply is 

 from a pure source, and does not require boiling, so there can 

 be very little doubt that the essential cause of the improvement 

 is the fact that flies do not breed in the trenching grounds. 



" At the beginning of this year the only station in the division 

 that was suffering from enteric fever was Jubbulpore, which has 

 an unquestionable water supply, but which is swarming with 

 flies, even in the cold weather. A visit to the trenching grounds 

 always brings back numbers of them, conveyed by horse and trap. 



" A consideration of the conditions of these three stations 

 points clearly to the assumption that trenching grounds are very 

 important factors in the causation of enteric fever.... I venture 

 to say that the evidence points strongly to the conclusion that... 

 the chief and most common method is by excrement when the 

 flies are bred in an enteric infected material. By this I mean 

 that one station may swarm v/ith flies, bred only from the excreta 

 of cows and horses, and yet have no enteric ; while another place, 

 where there are very few flies, but where these are bred from 

 human excreta either in or out of the station, may have an 

 epidemic, the source of infection being the excrement of the flies, 

 and the insects themselves being the carriers." 



Woodhouse (1908) "believes flies to be the channel by which 

 enteric fever is most frequently propagated in India " and 

 Aldridge (1907) came to the following conclusions: 



" There is a large mass of evidence pointing to the close 

 connection of epidemics of enteric fever with a great prevalence 

 of house-flies in dwellings, places where food is stored and latrines. 

 As far as observations up to the present have been made, the 

 seasonal prevalence of flies agrees very closely with that of 

 enteric fever. Flies are bred at certain seasons of the year in 

 enormous numbers in latrine trenches, and in excrement after it 

 has been buried in comparatively shallow trenches. Statistics 

 show that, in Indian cantonments with 500 British troops or 



