THE MILK SUPPLY OF CITIES IN RELATION TO THE 
EPIDEMIOLOGY OF TYPHOID FEVER. 
By Leslie L. Lumsden, 
Passed Assistant Surgeon, Public Health and Marine-Hospital Service. 
Milk is a favorable culture medium for the typhoid bacillus. 
Therefore, if a small particle of matter containing this organism is 
introduced into milk the organism may undergo rapid multiplication 
and become disseminated throughout the bulk of the milk. The tem- 
perature at which the milk is kept and the number and kind of other 
bacteria present affect the rate at which the multiplication of typhoid 
bacilli takes place, and in some instances, no doubt, the bacilli, after 
gaining access to a body of milk, die out before that milk is drunk. 
In the majority of instances, however, it is probable that the bacilli 
will survive and so endanger all susceptible persons into whose 
alimentary cr.nals such milk is taken. 
Considering the tremendous multiplication which the bacilli can 
undergo within twenty- four hours in milk it is easy to appreciate 
how one bottle or can of infected milk taken into a dairy and there 
mixed with a large volume of milk may be responsible for exposure 
to infection of several thousand persons. 
Dairy products, such as ice cream, buttermilk, butter and cheese, 
etc., made from infected milk may be factors in the spread of typhoid 
fever. 
Ice cream . — It has been proven experimentally that the process of 
freezing does not at cnce destroy all typhoid bacilli, and outbreaks 
of typhoid fever have been traced quite definitely to infected ice 
cream. 
Butter and cKeese . — Butter made from milk experimentally 
infected with typhoid bacilli may retain the bacilli, according to 
Bruck,® as long as twenty-seven days, and according to Washburn * & 
for as long as sixty days or more. Although it would seem, under 
ordinary circumstances, that the presence of many vigorous sapro- 
® Bruck, Deut. Med. Woch., vol. 29, 1903, p. 460. 
6 Washburn, Washington Medical Annals, Vol. VII, No. 1, 1908, p. 107. 
( 153 ) 
