278 



PATHOGENIC BACTERIA IN MILK 



met with is 28, and the lowest nil. The general average is 1 8-9 

 per cent. The returns may be tabulated as follows : — 



The mortality percentages in outbreaks not milk-borne, quoted 

 in the above table, have been taken from a representative work on 

 infectious diseases.^ General average returns have been selected. 

 Obviously, mortality percentages differ widely in accordance with 

 age incidence and other circumstances. Scarlet fever, for example, 

 at all ages gives a mortality of 8-o per cent. (81,350 cases), but in 

 children under five years of age the mortality is i6-2 per cent. 

 (17,310 cases). It is, of course, commonly a disease of children. 

 The typhoid fever return of 17-4 was calculated on 9223 cases at 

 all ages, and the diphtheria mortality percentage of 30-3 on 

 11,598 cases at all ages. In the last-named disease, age incidence 

 has a marked effect upon mortality. The percentage of 30-3 

 refers to cases treated at a period prior to antitoxin inoculation. 

 The mortality percentage of diphtheria in the Metropolitan 

 Asylums Board hospitals in 1894 (without antitoxin) was 29-6 

 per cent. ; in 1901 it had fallen to 12-5 per cent. ; and in 1902 was 

 I i-o per cent. 



It will be seen that in each of three diseases the mortality per- 

 centages in milk-borne outbreaks, including many thousands of 

 cases, is lower than the ordinary mortality from these same 

 diseases. 



^ A Manual of Infectious Diseases, by E. W. Goodall and J. W. Washbourn, 

 1896. For obvious reasons such returns will be lower if only hospital cases are 

 considered. The Metropolitan Asylums Board returns for 1902, for example, 

 show mortality percentage for scarlet fever, 3-4; for typhoid, 15-4; and for 

 diphtheria, ii-o. See Metropolitan Asylums Report, 1902, p. 212^. 



