BACTERIA IN CONDENSED MILK 391 



Freezing does not kill'' the bacteria in milk or cream; hence, ice 

 cream may and does convey all of the milk-borne diseases. Further- 

 more, the ice cream is often made in unsanitary places and handled 

 in an unsanitary manner; so that even though the milk be safe 

 there are numerous opportunities for infection, especially where ice 

 cream is vended on the street or from the little ice-cream stands on 

 the corner. 



Bolton reported experiments on the freezing of B. typhosus in 

 cream. One-twentieth of the organisms were alive after one month 

 and even after forty-five days some of the organisms were alive. 

 Furthermore, epidemics of typhoid have actually been traced to 

 ice cream. Gumming reported 23 cases which developed among 

 twenty-nine persons who partook of ice cream at a school picnic 

 at Helm, California, in 1916. Ice cream was the only food partaken 

 of by all, and as chocolate ice crream was the favorite flavor this 

 was determined to be the source of the infection. This was because 



(1) those not partaking of it did not become ill, (2) those partaking 

 of it but no other food were taken ill, (3) those eating chocolate ice 

 cream were taken with acute intestinal symptoms, and (4) those 

 eating the largest quantity of chocolate ice cream were the most 

 seriously ill. 



Dysentery is also often spread by means of ice cream. Smillie 

 studied 75 cases and found the etiology of them to be as follows: 



Cases. 



Contact with an acute case 21 



Contact with a carrier 2 



Contact with house cases 4 



Condensed milk epidemic 15 



Ice-cream cones 9 



Flies 6 



Milk 1 



Water 1 



Fruit 1 



Unknown 15 



The dysentery bacillus of Flexner was actually isolated from the 

 ice-cream cones. 



Hamilton has pointed out that ice-cream epidemics can be pre- 

 vented by (1) the use of ingredients with a clean sanitary history, 



(2) the use of properly cleaned utensils and a clean factory, anfl (3) 

 the proper handling of materials by individuals with a clean bill 

 of health. The first of these is to be controlled by the pasteurization 

 of the milk and cream; the second by frequent inspection; and the 

 last requires regular and careful inspection of all workers for com- 

 municable diseases. 



Bacteria in Condensed Milk. Sweetened condensed milk is not 

 intended to be sterile. The large quantity of sugar added prevents 

 the growth of microorganisms. But the unsweetened or evaporated 



