PUBLIC PROBLEMS I/T 



FREEDOM FROM SPECIFIC DISEASE GERMS 



The specific disease germs liable to be distributed by milk we 

 have already noticed. There seems to be only one method by 

 which milk can be guaranteed as free from disease germs. This 

 method is by treating the milk to a heat sufficient for pasteuriza- 

 tion. Inspection of the dairies will undoubtedly reduce the 

 danger of disease germs getting into milk ; but recognizing the 

 wide occurrence of bovine tuberculosis, the difficulty of detecting 

 it and the fact that the cows may have this disease in the udder 

 unsuspected; recognizing, too, that cases of walking typhoid 

 fever are possible, unsuspected by the patient or his friends, it 

 will be seen that no kind of dairy inspection, no matter how 

 rigid, can free the milk from the possibility of disease germs. 

 No subsequent care or cooling of the milk can destroy them, 

 if they have found entrance into the milk. Under these cir- 

 cumstances the sole practical method of assurance that the milk 

 shall contain no specific disease germs is by adopting pasteur- 

 ization or sterilization. All other methods of controlling the milk 

 supply must be looked upon as a means of improving its gen- 

 eral cleanliness and wholesomeness, and reducing the chances 

 of the presence of the disease germs; but none of them can 

 guarantee that the milk will be free from pathogenic bacteria. 

 The danger of infecting the milk by germs of contagious dis- 

 eases is so insidious that even in the best kept dairies and with 

 the best intentions it will sometimes happen. Some of the san- 

 itary dairies, kept under the highest condition of cleanliness, 

 have been suspected of having distributed disease. Therefore, 

 it follows that no methods are known by which a supply of fresh 

 untreated milk can be positively guaranteed as free from disease 

 germs. It must be recognized, however, that dairy inspection 

 and the methods adopted for the improvement of the quality 

 of the milk in general do greatly improve the milk by decreasing 

 the chances of the distribution of the disease germs, but they 

 do not entirely remove them. 



