INFECTION OF MILK HV FLIES 243 



before her removal to the hospital, August 28th. During the first 

 two weeks in September we received reports of numerous cases 

 of typhoid fever in the northern portion of Denver, and upon 

 investigation found that all these cases had been securing their 

 milk from this dairy. An inspection of this dairy was then made, 

 and in addition to learning of the illness of the dairyman's wife, 

 we also found the dairyman himself suffering with a mild case of 

 typhoid fever, but still up and delivering milk. The water supply 

 of this dairy was fairly good. However, we found that the stools 

 of both the wife and husband had been deposited in an open privy 

 vault located thii'ty-five feet from the milk-house, which was 

 unscreened and open to flies. The gelatine culture exposed for 

 thirty minutes in the rear of the privy vault and in the milk- 

 house among the milk-cans gave numerous colonies of typhoid 

 bacilli, as well as colon bacilli and the ordinary germ-life. The 

 source of infection in the dair^-man's wife's case is unknown, but 

 I am positive that in all the cases that occurred on this milk route 

 the infection was due to bacilli carried from this vault by flies and 

 deposited upon the milk-cans, separator and utensils in the milk- 

 house, thereby contaminating the milk. The dairyman supplied 

 milk to 143 customers. Fifty-five cases of typhoid fever occurred, 

 and six deaths resulted therefrom ^" 



Washburn (1910) has shown how insanitary conditions in 

 localities where little attention is paid to the prevention of health 

 render easy the infection of food by flies and the dissemination of 

 the typhoid bacillus. In the report of an investigation into the 

 prevalence of typhoid fever at Charlestown, West Virginia, U.S.A., 

 Ridlon (1911), in discussing the epidemiological fixctors, states: 

 "The most probable source of infection in five cases was from 

 flies. These cases were located within two hundred feet or less 

 of other cases where the disinfection of the stools was inefficient, 

 where there were no screens and where the abundant flies had free 

 access to both dejecta of patients and the food." He continues : 

 " That flies under the proper conditions can be a prominent factor 

 in the spread of infection is an undisputed fact, as is also the fact 

 that their prevalence can be greatly diminished by proper care of 



^ Tlie House-fiy at the Bar, Indictment Guilty or not Guilty ? The Merchants' 

 Association of New York, April, 1909, p. 48. 



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