DISEASE GERMS IN MILK 



source of infection must be looked for. This will commonly 

 exclude the water supply, since if a water supply is infected 

 the trouble is apt to last a long time and will never be confined 

 to one single period of infection. The next step will be to de- 

 termine whether all persons suffering from the disease have 

 had any one point of contact, as having attended a banquet, 

 for example, at any particular time. If so, the disease may be 

 traced to something used during the banquet. If no such com- 

 mon point is found, the next point of suspicion would be the 

 milk supply, and the ques- 

 tion would be raised wheth- 

 er all of the persons suffer- 

 ing from the disease had 

 obtained milk from a com- 

 mon source. If this is 

 found to be the case, the 

 matter is practically demon- 

 strated, and it is only nec- 

 essary to trace the milk to 

 its origin, and find the 

 methods by which it is dis- 

 tributed. There is usually 

 little difficulty in detecting 

 the source of contamina- 

 tion, either from a typhoid fever patient in the dairyman's 

 family or employ, or from an infected well or brook, from 

 which water has come into contact with the milk cans. 



Diphtheria. A few epidemics of this disease have been at- 

 tributed beyond doubt to milk. 1 In these cases the infection 

 occurs after the milk has been drawn from the cow, although 



1 Abbott. Jour. Path, and Bact., II., p. 35, 1894. 

 Dean and Todd. Jour, of Hyg., II., 1902. 

 Klein. Cent. f. Bact., vii., p. 489, 1890. 

 Mackenzie. Med. News, p. 180, 1893. 

 Marshall. Jour, of Hyg., vii., p. 32, 1907. 



FIG. 40 DIPHTHERIA BACILLI 

 (LEHMANN & NEUMANN) 



