DISEASES CAUSED BY INFECTED MILK 127 



limited to the distribution of the milk. Approximately 

 eight hundred cases occurred in the Back Bay district, over 

 one thousand cases occurred in Cambridge, and at least 

 two hundred and sixty-five in Brookline, making a total 

 of over two thousand cases. The disease began about May 

 8, reached its maximum May 14, and suddenly ceased 

 May 19 to 22. Twenty-two per cent of the households 

 affected had three cases or more. Females suffered twice 

 as much as males, and adults more in proportion than 

 children. Two-thirds of the fatalities occurred at ages 

 above fifty-five and one third at ages above seventy-five. 



The distribution of the epidemic exactly coincided with 

 that of one of the two main milk supplies of the Deerfoot 

 Company. It affected the particular districts in Boston, 

 Brookline, and Cambridge where this milk was used, and 

 it broke out simultaneously in Marlboro and Southboro, the 

 only other towns to which it was distributed. Eighty-five 

 per cent of the cases in Boston and Cambridge were upon 

 the delivery Hst of the dairy, while an additional eight per 

 cent were stated by physicians to have used the milk, 

 though not listed as subscribers. In sharp contrast to this, 

 the Deerfoot supply makes up only one per cent of the 

 Boston and two per cent of the Cambridge total. In Brook- 

 line sixty-five per cent of the cases were on the Deerfoot 

 list and eight per cent more stated to have used the milk. 

 In this town the Deerfoot supply constitutes about seven 

 per cent of the total. A study of the delivery lists for Brook- 

 line and Cambridge showed that in each case about one 

 family out of every four supplied had been infected. 



One of the features of special interest concerning this 

 outbreak was that the Deerfoot milk has always been a 

 particularly clean, fresh, and satisfactory supply. It is 

 obtained from tuberculin-tested cows, under constant 

 veterinary supervision, and the milk itself is subjected to 

 daily chemical and bacteriological tests. The milk is bot- 

 tled at the dairy, the bottles are sterilized, and all reason- 



