CHAPTER VI. 

 DISEASE-PRODUCING BACTERIA IN MILK. 



73. Milk a medium for pathogenic bacteria. Not 



only is milk an excellent food for fermentative bacteria, 

 but a not inconsiderable number of disease organisms 

 also find in it a suitable substratum for development. In 

 so far as these occur in milk under natural conditions, 

 they become a serious menace to public health. Statis- 

 tical evidence shows that quite a large number of epi- 

 demics have been traced to a contaminated milk-supply, 

 which has served as a vehicle for the transmission of dif- 

 ferent disease organisms. The following table, prepared 

 by Freeman, represents the outbreaks that have occurred 

 since 1880. 



Number of disease epidemics traced to contaminated milk- 

 supply. 



Typhoid fever 53 Foot and mouth disease 2 



Scarlet fever 26 Throat trouble 3 



Diphtheria 11 Cholera 1 



While such evidence can only be approximately correct, 

 still the data at hand is overwhelming as to the relation 

 of disease bacteria to milk. 



These organisms may be considered under the follow- 

 ing heads : 



1. Pathogenic bacteria causing diseases common to 

 man and beast, which may be transmitted directly to 

 man through the medium of the milk, as in tuberculosis. 



2. Pathogenic bacteria that can thrive in milk under 

 saprophytic conditions, and which gain access to it sub- 

 sequent to its withdrawal, as in typhoid fever. 



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