CHAPTER IV 



DISEASES CAUSED BY INFECTED MILK 



We now leave the question of dirty milk to consider that 

 of infected milk. By infected milk we mean milk contain- 

 ing the specific virus of one of the infectious diseases. When 

 infected milk is consumed raw it is very apt to become in- 

 fective milk. The diseases known to be conveyed by milk 

 are tuberculosis, typhoid fever, scarlet fever, diphtheria, 

 sore throat, foot-and-mouth disease, malta fever, milk sick- 

 ness, and occasionally others. This Hst does not include 

 the dysenteries and gastro-intestinal diseases of babies 

 that also are associated with impure milk. 



Some of the diseases mentioned come from the lower 

 animals; some from man. Thus bovine tuberculosis, foot- 

 and-mouth disease, and milk sickness come from the cow; 

 malta fever is primarily a disease of goats. The more seri- 

 ous infections in milk, however, come from human origin. 

 Man contracts most of the diseases to which he is heir from 

 his fellow men. Cows do not have typhoid fever, scarlet 

 fever, or diphtheria, so that when milk contains the viruses 

 of these diseases the infection usually gets into the milk 

 either directly or indirectly from human sources. 



When all the diseases due to impure milk are counted up 

 the indictment is a strong one. While pointing out the dan- 

 gers, we must ever be mindful of the fact that our object 

 is not to discourage the use of milk — only to discourage 

 the production and use of impure milk. We want to encour- 

 age the use of good milk as one of the best and cheapest 

 foods on the market. 



Milk-borne epidemics vary greatly in prevalence and 

 severity. Only one qv iYfQ persons may be involved, or the 



