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 Bacillus typhosus. 
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 
temperature at which the milk is kept and the number and kind of 
the other bacteria present affect the rate at which the multiplication 
of the B. typhosus 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 bacillus will survive and so endanger all susceptible persons 
into whose alimentary canals such milk is taken. 
Considering the tremendous multiplication which the bacillus can 
undergo within twenty-four hours in milk it is easy to appreciate 
how one can or bottle 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 have to be kept in mind as possible 
factors in the spread of typhoid fever. 
Ice cream . — It has been proven experimentally that the process 
of freezing does not at once destroy all typhoid bacilli, and outbreaks 
of typhoid fever have been traced quite definitely to infected ice 
cream. 
Butter and cheese . — Bruck a has shown that butter made from milk 
experimentally infected with B. typhosus may retain the bacillus for 
as long as twenty-seven days. Under ordinary conditions, however, 
it would seem that the presence of many vigorous saprophytes, the 
washing out of large numbers of bacteria in the buttermilk, and the 
a Bruck, Deutsche Med. Woch., 1903, XXIX, p. 460, Milk. 
(151) 
