76 MILK AND THE PUBLIC HEALTH 



CHAP. 



the maid-servants, one of them being the nurse, were attacked, 

 both of whom drank raw milk ; while the head of the house, 

 who only drank milk in tea, escaped, as did also the two 

 children (eight months and four years), receiving all their milk 

 boiled ; and this in spite of the fact that the nurse, whose sore- 

 throat was typical, but not severe, continued to look after 

 them." 



A more detailed illustration of the relationship between 

 the incidence of attack and the amount of milk consumed is 

 furnished by Sir William Power in the outbreak of milk- 

 borne scarlet fever at Wimbledon in 188*7. He gives the 

 following table : l 



DIPHTHERIA OUTBREAKS SPREAD BY MILK / 



As long ago as 1878 Power adduced evidence that an 

 outbreak of diphtheria in Kilburn and St. John's Wood, 

 London, was spread by milk. Since that date many milk- 

 borne epidemics of this disease have been recorded, although 

 the total is smaller than of milk outbreaks of scarlet fever or 

 typhoid fever. 



Trask 2 has summarised 51 such diphtheria outbreaks 

 (including those collected by Busey and Kober and by Hart) 

 spread by milk, while there are, no doubt, a very large 

 number which have never been recorded. 



The outbreaks summarised by Trask show a very variable 

 case-mortality, being for some as low as 1*5 per cent and for 

 others as high as 30 per cent, or even higher. The epidemics 

 with a high case-mortality are for the most part not recent, 

 and refer to pre-antitoxin times; The highest case-mortality 



1 LOG. cit. 

 2 Bulletin No. 41, Public Health and Marine Hospital Service, 1908, p. 32. 



