3i6 



PATHOGENIC BACTERIA IN MILK 



In the milk-borne epidemics of typhoid which we have studied, 

 numbering not far short of 200, and of which about 160 are in our 

 opinion sufficiently proved cases, we have arrived at certain figures 

 respecting this matter of exact channel of infection. Unfortunately 

 in many cases sufficient investigation has not been made for any 

 reliance to be placed upon it. But in between 70 and 80 typhoid 

 epidemics, it has been possible to obtain the likely channel of 

 infection. The results are as follow. 



Milk-borne typhoid epidemics probably started : — 



(a) By cases of typhoid at the farm or milk-shop . = 70 per cent. 



(6) By cases of typhoid at the farm . . . = 40 „ 



(c) By cases of typhoid at the milk-shop . , = 30 „ 



(d) By using polluted water for dairy purposes, method 



of pollution unknown . . . . = 20 ,, 



(e) By insanitation at the farm or milk-shop and 



miscellaneous . . . . . = 10 ,, 



It should be understood that many of the cases included under 

 divisions {a) {U) and id) were really infections conveyed by water, 

 or in "cleansing" the milk utensils. In one of the first outbreaks 

 recorded in this country (namely at Islington in 1870), Dr Ballard | 

 showed that the water used for washing the milk-cans was the 

 infected medium. In this epidemic, of 142 families obtaining 

 their milk supply from a certain milk dealer, 70 (or 50 percent.) 

 contracted typhoid fever, of whom about 54 families took the 

 same supply regularly, whilst the others took it at the time of] 

 infection. The whole of the infection, though attributable to 

 previous cases of typhoid, came, as far as could be proved, by using ^ 

 infected water for cleansing the milk-cans. 



Abstracts of Typical Milk-borne Outbreaks of 

 Typhoid Fever.^ 



Armley, 1872 {July). 



Total number of cases . . 107 

 Deaths . . . . .11 

 Number of families invaded 



supplied by milkmen 37-5 per cent. 

 Number of polluted milk-sources i 

 Number of milkmen . . . i 



Circumstances implicattjtg the milk 

 supply. — Adults affected 59 ; persons 

 aged S-14 years, 36 ; Under 5 years, 



ID. Thirty-seven per cent, of the 

 families supplied by farmers having 

 implicated milk were attacked : 5 per 

 cent, of the families supplied by 18 

 other milkmen or not taking milk 

 at all. The fever picked out the 

 customers of a certain dairyman in a 

 remarkable manner, and the largest 

 consumers of the suspected milk were 

 amongst the earliest, and the smallest 

 consumers among the latest, attacked. 



1 See Note on p. 290 regarding Abstracts. 



