DISEASE GERMS IN MILK. I () - 



Scarlet Fever and Diphtheria. There is positive evidence that 

 these two diseases may be distributed by milk and that some 

 epidemics are attributable to the milk-supply. The cause of scarlet 

 fever is yet uncertain, and it is not known whether cows can contract 

 the disease and then produce milk already contaminated, or whether, 

 as in typhoid fever, the contamination of the milk is wholly secondary. 

 A few epidemics of scarlet fever have been traced to the cow with more 

 or less certainty, and it is beyond doubt also that the milk may 

 become infected with the cause of this disease by secondary 

 contamination. The farmer should, therefore, take 

 precautions to prevent any person from working in 

 the dairy who is recovering from scarlet fever. 



Diphtheria is produced by a well-known bacillus 

 (Fig. 41). Here again there seems some doubt whether 

 cows have the disease. It is certain, however, that the diphtheria bac- 

 milk may become secondarily infected through con- 

 valescent diphtheria patients working in the dairy and handling the 

 milk. Some instances of diphtheria have been traced to such a cause. 



Diarrheal Diseases. Besides the diseases mentioned, milk 

 is responsible for a portion of those obscure diseases characterized 

 by diarrheal troubles, which are especially prevalent in warm 

 weather. Among these are cholera infantum, which is responsible 

 for the death of so many children, and summer complaint, which is 

 less serious. These troubles are not yet so well understood as the 

 others we have mentioned. They do not appear to be caused by 

 any single specific bacterium, but are probably due to the excessive 

 multiplication of a number of certain kinds of bacteria in the milk. 

 That they are due to milk bacteria is proved by the facts that (i) 

 they occur most frequently at the seasons of the year when milk 

 bacteria are most numerous; (2) they are more prevalent among in- 

 fants fed upon cow's milk than among breast-fed children. What 

 kinds of bacteria are at fault in the production of these diseases 

 we do not know. Quite a number of bacteria are found in milk 

 which produce poisonous secretions and which may be agents in 

 the production of these obscure diseases. For the purpose of 

 our discussion it is sufficient to state that they are probably due 



