TYPHOID FEVER 109 



fected with typhoid fever on the dairy farm first 

 infected, on the farm upon which the creamery was sit- 

 uated and on 4 other farms, only one farm remaining 

 exempt. Through contagion, the disease was carried 

 from these farms to 7 other families and 14 more per- 

 sons became affected. 



Hart's and Freeman's collections of the milk epi- 

 demics in the literature gave an idea of the importance 

 of this method of transmission of typhoid fever. Hart 

 collected the established milk epidemics from 1857-81 

 and found accounts of 51, with 3500 cases of the disease 

 and 350 deaths, while Freeman found 53 epidemics from 

 1880-96. The number of milk epidemics observed since 

 then is proportionately greater, no doubt because this 

 means of transmission is better known and, therefore, is 

 more frequently recognized than before. 



While in the case of some epidemics it is quite easy 

 to prove that the infection of the milk came from a sick 

 person working with the milk, in other cases everything 

 points to the producing farm as the seat of infection, but 

 may not reveal the ultimate origin of the contagion. In 

 such cases attempts have been made to trace the infec- 

 tion to a disease of the cows, but without sound basis, 

 for no instance is known wherein domestic animals have 

 suffered from any disease caused by the typhoid 

 bacillus. 



From our knowledge of the epidemiology of typhoid 

 fever, it may be said with assurance that milk may be 

 infected with typhoid bacilli through the addition of 

 water (in washing the vessels or through adulteration 

 with water) or by bacteria from patients or conva- 

 lescents. 



It is a well known fact that many epidemics of this 

 disease have been traced to infection from impure drink- 

 ing water, and it is self evident that milk, which is favor- 



