154 
phytes, the washing out of large numbers of bacteria in the butter- 
milk, and the salting would lessen the chances of typhoid bacilli 
remaining in the butter, yet in view of the experimental evidence this 
dairy product should be kept in mind as a possible factor in the 
spread of typhoid fever infection and its manufacture from pre- 
sumably infected milk prohibited. 
Buttermilk of course would be fully as dangerous as the cream 
from which it was derived. 
Cheese . — The time required for the ripening of cheese makes the 
chances of infection from this dairy product certainly very slight. 
Butter and cheese from a given source are usually so widely dis- i 
tributed that should an outbreak of typhoid fever in a large city be | 
caused by infection in them it would be very difficult to trace unless i 
the outbreak were very pronounced and other possible factors could be i 
excluded so that attention would be directed to these dairy products. i 
WAYS IN WHICH THE TYPHOID BACILLUS MAY GET INTO MILK. 
At the dairy farm . — The milk supply for the average American 
city is obtained from a large number of dairy farms, and the lia- 
bility of cases of typhoid fever developing every year among per- 
sons living on these farms can be readily appreciated. The city of 
Washington, for example, obtains its milk supply from about 1,000 
dairy farms. Estimating the average number of persons living at 
a dairy farm at about 7, and considering the fact that every j^ear, 
in the United States, about 1 j^erson in every 300 has typhoid fever, 
some 25 cases per year may be expected to occur on the dairy farms 
supplying Washington with milk. 
AVlien cases exist on the dairy farms, there is, in the majority of 
instances, much likelihood of the infection being conveyed from the 
patients to the milk. Frequently the cases are not recognized as 
typhoid Until the second or third week of illness, during which period 
no precautions are taken. In many instances there are mild cases 
unattended by a physician and cases following an irregular course, 
which go through the attack without being recognized. Too fre- 
quently when the cases are correctly diagnosed in the comparatively 
early stages of the disease the disinfection of the patient’s stools and 
urine and the other precautions necessary to prevent the spread of 
the infection are found to be woefully inefficient. 
When the infection is not destroyed as it leaves the body of the pa- 
tient, there are many ways in which the typhoid bacilli may be carried 
from a patient on a dairy farm to the milk. Thus, those caring for 
the sick or handling the soiled bedding or excreta of the patient may 
convey the infection on their hands or clothing. Persons who have 
recovered from the symptoms of the disease, but are still discharging 
the bacilli in their stools or urine may directly contaminate the milk ^ 
