98 Dairy Bacteriology. 



cases have occurred. In this interim the original cause of 

 infection may have ceased to be operative. 



Typhoid fever. With reference to the diseases likely to 

 to be disseminated through the medium of milk, infected 

 after being drawn from the animal, typhoid fever is the 

 most important. The reason for this is due (1) to the wide 

 spread distribution of the disease; (2) to the fact that the 

 typhoid bacillus is one that is capable of withstanding 

 considerable amounts of acid, and consequently finds even 

 in raw milk containing the normal lactic acid ba'cteria con- 

 ditions favorable for its growth. 1 Ability to grow under 

 these conditions can be shown not only experimentally, but 

 there is abundant clinical evidence that even a slight infec- 

 tion often causes extensive outbreaks, as in the Stamford, 

 Conn., outbreak in 1895 where 386 cases developed in a few 

 weeks, 97 per cent of which occurred on the route of one 

 milkman. In this case the- milk cans were thoroughly and 

 properly cleaned, but were rinsed out with cold water from 

 a shallow well that was found to be polluted. 



The most common mode of pollution of milk with typhoid 

 organisms is where the milk utensils are infected in one 

 way or another. Generally, this arises from the use of pol- 

 luted water in cleansing the vessels or in intentional water- 

 ing of the milk. Second in importance is the carrying of 

 infection by persons serving in the dual capacity of nurse 

 and dairy attendant. 



Cholera. This germ does not find milk so favorable a 

 nutrient medium as the typhoid organism, because it is 

 much more sensitive toward the action of acids. Kitasato* 



1 Heim (Arb. a. d. Kais. Gesundheitsamte, 1889, 5:303) finds it capable of living 

 from 20-30 days in milk. 

 'Kitasato, Arb. a. d. Kais. Gesundheitsamte, 1:470. 



