156 MILK AND THE PUBLIC HEALTH 



CHAP. 



While these facts are generally recognised there are 

 several problems in relation to this subject which are still 

 matters of controversy. For instance, there is no unanimous 

 opinion as to whether infection is specific and due to a 

 special organism or whether we have to deal with bacterial 

 poisoning through the toxic products of a large number of 

 bacteria such as B. coli, etc. This question is connected with 

 that of the case-to-case infectivity of the disease. 



Delepine 1 found that milk samples received by him in 

 hot weather, o.r after some time in transit, were infectious to 

 guinea-pigs to a much higher degree than milk examined 

 after only a short interval, or for which proper precautions 

 had been taken to keep it cool. From his investigations he con- 

 cluded that " epidemic diarrhoea of the common type occur- 

 ring in this country is, apparently in the great majority of 

 instances, the result of infection of food by bacilli belonging 

 to the colon group of bacilli, which are present at all times 

 in faecal matter." He further concluded that the disease is 

 only caused when the infection of the food is massive from 

 the first, or the food is kept for a sufficient length of time 

 and under conditions of temperature favouring the multiplica- 

 tion of these bacilli. In his view the milk was frequently 

 infected at the farm or during transit. 



On the other hand, there is a mass of evidence which is 

 overwhelmingly in favour of the view that the place of 

 infection is the home, and indeed any other supposition does 

 not offer an adequate explanation of the facts. For example, 

 the incidence, as Newsholme, Sandilands, the writer, and 

 others, have shown, is proportionately higher on those fed 

 with condensed milk (which is certainly infected in the 

 home) than on those fed with cows' milk. 



Thus in an outbreak of epidemic diarrhoea causing over 

 50 deaths, the figures for the feeding of children under one 

 year of age were as follows : 2 



1 Journ. of Hygiene, 1903, iii. 68. 

 - W. G. Savage, Annual Report, Colchester, 1904. 



