30 



CITY MILK SUPPLY 



Classification of Milk-borne Diseases. Diseases that man contracts 

 from milk are of two classes, namely: 



Class I. Diseases of animal origin. 



A. Definite diseases : tuberculosis, foot-and-mouth disease, Malta fever 

 and anthrax. B. Indefinite ailments : diarrheal infections and possibly 

 contagious abortion. 



Class II. Diseases of human origin: typhoid fever, paratyphoid 

 fever, diphtheria, scarlet fever, tuberculosis, Asiatic cholera, septic sore 

 throat and possibly others. 



Tuberculosis. Of all the diseases transmitted by milk, tuberculosis 

 is the most important both because of the frequency with which it is con- 

 veyed and because of its serious nature. The tuberculosis that is derived 

 from milk may be either of human or bovine origin. Human infection of 

 milk is rarer than bovine and in practically every case, except conceiv- 

 ably from air or flies, comes from some one that is handling the milk 

 and has the disease. A tuberculous milker who spits on his hands has 

 every opportunity to wash the germs into the milk and the spray that is 

 ejected in the cough of a consumptive milk handler may fall into the milk 

 and infect it. Hess in 1908 in New York City actually isolated the 

 human tuberculosis bacillus from a sample of market milk. However, 

 danger from this source is relatively small and is controllable so that 

 human tuberculosis is of less importance so far as milk is concerned 

 than the tuberculosis that is of bovine origin. 



TABLE 14. TABULATION OF PARK AND KRUMWIEDE'S TUBERCULOSIS CASES 



In 1901 Koch announced that there was practically no danger of 

 man contracting tuberculosis from cattle. The statement was at once 

 challenged and many bacteriologists set themselves to find out the 

 truth of the matter. To date the reports of the English Royal Com- 

 mission, of the German Commission and of Park and Krumwiede in 



