DISEASES COMMUNICABLE IN MILK 85 



milk next morning. In all there were 59 cases in 52 households that were 

 located in 10 different cities and every one of the patients is known to have 

 used the milk. 



Impossibility of Protecting the Milk from Infection. The recital of 

 these specific instances of milk infection makes it obvious that no pro- 

 ducer or purveyor of raw milk can be absolutely certain that the article 

 that he is marketing is free from contagion. Pestilence in invisible form 

 and devious ways sneaks into the dairy so unobtrusively that even the 

 most careful and observant are unaware that anything is wrong till the 

 blow falls. There exist three types of cases, or stages of communicable 

 disease that may at any time bring infection into the dairy, and which 

 it is impossible to guard against. 



First are cases in the prodromal stage particularly of typhoid fever 

 where germs are thrown off from the body before the victim feels the 

 warning pains of illness. 



Second are the ambulatory cases where the sick continue at their 

 usual occupation, though feeling excessively tired, mean or distressed. 

 These cases are apt to do a great deal of harm for they may distribute 

 the virus of their disease for a considerable period and in many places 

 before they are discovered. Indeed, some never are found out and these 

 constitute the " missed " cases which are decidedly to be reckoned with 

 in preventive medicine. The epidemic of scarlet fever that occurred 

 in Boston, Mass., in 1910, was attributed to a missed case on some one 

 of the 250 farms that supplied the dealer involved. There were 842 

 cases in Boston and its suburbs. Of 409 cases in the city proper 286, 

 or approximately 70 per cent., were on the route of this one dealer. It 

 was on April 25, that the milk was suspected and on that date orders 

 were given to pasteurize it and sterilize the utensils. On April 27, 

 pasteurization was begun, on the 29th reported cases reached a maximum 

 of 123 reported new cases. Thereafter the epidemic declined and died 

 out on May 7. 



Third are the carrier cases. There are the acute carriers, persons 

 that have convalesced but still give off the germs of the disease that 

 affected them. In 1901, in Beverly, Salem and Bakers Island, there 

 occurred suddenly 60 cases of scarlet fever among the customers of a 

 single dealer. The trouble was traced to one of the farms whence his 

 supply came, whereon a convalescent milker had infected the milk. 

 Chronic carriers present a more serious problem. They are those that 

 have been ill of infection made an apparently complete recovery but for 

 months or years thereafter continue to scatter the specific germs of their 

 malady. It is estimated that about 2 per cent, of all typhoid fever 

 patients continue to discharge the bacilli in the feces and urine for an 

 indefinite period after recovery. Of the many instances that might be 

 cited to illustrate the infection of a milk supply by a chronic carrier, one 



