36 CLEAN MILK 



In fresh butter, cheese and buttermilk. Inoculation of milk into* 

 guinea pigs, and growth of germs on appropriate culture material 

 from samples of milk, may lead to the finding of disease germs in 

 milk. 



Of 253 milk-borne epidemics collected by Trask, and occurring 

 since 1895, 179 were typhoid fever; 51 were scarlet fever; and 23 

 were diphtheria. Both the germs of typhoid and diphtheria may 

 multiply in milk, especially if it is not properly cooled. Beginning 

 with 78 typhoid fever germs in fresh milk there were 6,000 in 24 

 hours and 440 millions in seven days. Starting with 39 diphtheria 

 germs in fresh milk, there were 1,170 in 24 hours and 19 millions 

 at the end of a week (Eyre). 



There are certain characteristics of epidemics originating from 

 milk which will lead one to distinguish them from those derived 

 from other sources. Thus the sudden onset. A number of cases 

 suddenly appear in one day. Persons drink the infected milk at 

 the same time and therefore become sick at about the same time. 



Of next importance is the fact that all those taken sick have 

 milk from the same source. This does not mean that they have 

 taken milk from the same milkman, as the original infected milk 

 may be mixed with other milk and may be sold by many milk- 

 men. However, it is possible to trace the source of the infection 

 by looking into the sources of supply of the milkmen distributing 

 milk to the sick. To accomplish this it will be of great assistance 

 if physicians be required to report the name of the milkman supply- 

 ing milk to each contagious case reported by them. The decline of 

 milk-borne outbreaks may be also more sudden than is usual in 

 others. But this is not the case if the milk is constantly contamin- 

 ated, nor if there are many new cases arising from contact with 

 the sick. Several cases are apt to occur simultaneously in the same 

 house in milk-borne epidemics. Then again those who drink most 

 milk are prone to be the patients — as children and the well-to-do. 

 The period of development of the disease is likely to be shorter and 



