CHOLERA 373 



contact with the milk, manufactured or not Absolute cleanness 

 is most difficult to obtain, if not practically impossible. Occasional 

 infection must, therefore, occur. 



2. To guard against the effects of accidental faecal infection, 

 milk should be consumed fresh, when possible. When it cannot be 

 consumed fresh it should be refrigerated, i.e. kept at a temperature 

 below 4' C. When it cannot be used fresh or refrigerated, it 

 should be sterilised by heat 



3. Greater domestic and municipal cleanliness is an essential 

 requirement This must include the cleanly preparation of food, 

 and particularly the handling and storage of milk ; the cleansing 

 of milk-bottles ; reduction of dust in houses, courts, and streets ; 

 impervious roads and paving ; and the substitution of wet cleans- 

 ing for dry cleansing, and frequent cleansing for infrequent 



4 "A crusade against the domestic fly, which is most numerous 

 at the seasons and in the years when epidemic diarrhoea is most 

 prevalent, and probably plays a large part in spreading infection " 

 (Newsholme). 



F. Cholera 



Cholera is rarely spread by milk, but as several outbreaks of 

 the disease have been traced to milk, a note may be added on the 

 subject 



The cholera bacillus is unable to live long in an acid medium, 

 hence its life in milk is a limited one, and generally depends upon 

 some alkaline change in the milk. Heim found that cholera germs 

 would live in raw milk from one to four days, depending upon the 

 temperature. D. D. Cunningham, from the results of a large 

 number of investigations in India, concludes that the rapidly 

 developing acid fermentations normally or usually setting in, con- 

 nected with the rapid multiplication of other common bacteria and 

 moulds, tend to arrest the multiplication of cholera bacilli, and 

 eventually to destroy their vitality. Boiling milk appears, on the 

 contrary, to increase the suitability of milk as a nidus for cholera 

 bacilli, partly by its germicidal effect upon the acid-producing 

 microbes, and partly that it removes from the milk the tnormous 

 numbers of common bacteria, which in raw milk cause such keen 

 competition that the cholera bacillus finds existence impossible. 



Professor W. J. Simpson has placed on record an interesting series 

 of cholera cases on board the Ardenclutha, in the port of Calcutta, 

 which arose from drinking milk which had been polluted with one- 

 quarter of its volume of cholera-infected water. This water came 



