TYPHOID FEVER I45 



point of view of practical experience and it is needless to multiply 

 instances to prove that swarms of flies in camps with open 

 latrines, used by incipient and ambulant cases of typhoid and 

 typhoid carriers, constitute a very serious danger. 



Austen (1904, p. 658) considers that many cases of intestinal 

 myiasis at home are due to flies, belonging to the genus Fannia, 

 ovipositing on the anus of the patient when using a country 

 privy, and thinks that in camps flies may inoculate typhoid in a 

 similar way. 



Summary. 



It has been shown experimentally that flies are capable of 

 carrying and distributing B. typhosus, by means of infected feet, 

 proboscides and faeces for several days, and on several occasions 

 this organism has been isolated from ' wild ' flies caught in 

 places where outbreaks were in progress. In clean and well- 

 sewered cities flies have few opportunities of infecting themselves, 

 but under suitable conditions may act as carriers of the disease 

 mainly by infecting themselves with bacilli derived from mild 

 unrecognized cases and ' carriers.' In smaller towns and in 

 country districts their opportunities are greater, but up to the 

 present sufficient evidence has not been obtained on which to 

 found a final judgment. Sedgwick and Winslow (1902), after 

 a careful study of the seasonal prevalence of typhoid fever, came 

 to the following conclusions : " Of the three great intermediaries 

 of typhoid transmission, fingers, food and flies, the last is even 

 more significant than the others in relation to seasonal varia- 

 tion... .There can be little doubt that many of the so-called 

 ' sporadic ' cases of typhoid fever, which are so difficult for the 

 sanitarian to explain, are conditioned by the passage of a fly 

 from an infected vault to an uprotected table or an open larder. 

 The relation of this factor to the season is of course close and 

 complete, and a certain amount of the autumnal excess of fever 

 is undoubtedly traceable to the presence of large numbers of 

 flies and to the opportunities of their pernicious activity." 



Medical officers in India have published numerous articles 

 placing on record their belief that flies, bred in the trenching 

 grounds, are important agents in spreading the disease. In 



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