Disease Bacteria in Milk. 83 



traced to numerous causes, among which the following 

 are most important: 



1. Direct transmission to the milk from person conva- 

 lescing from the disease. 



2. Indirect transmission by milker also serving as 

 nurse to patient. 



3. Indirect transmission through polluted water-sup- 

 ply where same is used for cleansing milk vessels. 



All of these sources of infection can be readily gov- 

 erned with a little care. If typhoid fever is present in 

 the family of a milk-handler, especial care should be 

 taken that no one has any access to the patient that has 

 anything to do with the milk. In case of disease in fam- 

 ily, all water used in cleaning cans should first be boiled 

 or else secured from a source in which contamination is 

 impossible. Wells in vicinity of dwellings are often 

 infected with disease germs that are derived from the ex- 

 creta, and if such water is used, infection of milk- supply 

 is possible. 



In some cases, the disease has been spread by infect- 

 ing a general creamery supply, the contaminated skim- 

 milk distributing the virus of the disease. In the Wei- 

 ply epidemic in England in 1893, twenty-three cases 

 appeared among the patrons of a single factory. 



The typhoid fever organism is able to thrive in milk 

 for a considerable time (20-35 days according to Heim) * , 

 on account of its tolerance toward weak acids. Even in 

 butter and cheese these organisms are able to live, but 

 the conditions are so unfavorable and the probability of 

 infection so slight as to practically eliminate such a 

 source . 



82. Cholera, diphtheria, scarlet fever, etc. 



1. Cholera. Milk also functions as a medium for the 



1 Heim, Arb. a. d. k. Ges. Amte, 5: 303. 



