DIARRHEAL DISEASES. I2Q 



The cause of this class of diseases is unknown. That they 

 are produced in general by some bacterial agency is ex- 

 tremely probable, though hardly as yet capable of absolute 

 demonstration. The extreme probability that milk bacteria 

 are the cause of this general class of troubles is indicated by 

 several series of facts. 



1. They are more common at those seasons of the year 

 when the milk bacteria are most abundant. In the summer 

 months the number of bacteria in milk rises commonly to 

 many millions per cubic centimeter, and with this rise in 

 number of bacteria the cases of intestinal disease among 

 children increase. To what extent the hot weather con- 

 tributes directly, and to what extent the increased number of 

 bacteria are concerned in producing these troubles cannot be 

 positively stated. 



2. The number of cases of such diseases is roughly pro- 

 portional to the purity of the milk. Breast-fed children, it is 

 true, do frequently have similar troubles during hot weather ; 

 but in breast-fed children they are very much less common 

 than they are in children fed upon cow's milk. From what 

 has already been stated it is evident that milk drawn 

 directly from the mother's breast will be far less contami- 

 nated .with bacteria than cow's milk. 



3. Treatment of milk which destroys the bacteria has a 

 decided influence in checking these intestinal diseases. The 

 method which is commonly adopted is sterilizing or pasteur- 

 izing (see Chap. VI.), and this results either in the complete 

 destruction of the bacteria or in a great reduction in their 

 numbers. It has been found by a great amount of experi- 

 ence that such sterilizing or pasteurizing reduces the amount 

 of intestinal sickness. In cases of cholera infantum or 

 similar diseases the sterilizing of the milk, which causes the 

 destruction of bacteria, makes it possible for the physician to 

 control the disease very much more readily than he can with- 



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