THE STREPTOCOCCI 421 



of the mono-nuclear variety. The appearance of these processes, 

 according to MacCallum, is quite different from that seen in the 

 ordinary forms of bronchopneumonia. 



EPIDEMIC SORE THROAT DUE TO MILK INFECTION 



Sore throat epidemics traceable to milk have been observed in 

 England since 1875. The onset of these cases is usually accompanied 

 by sudden chilliness, with muscular soreness, headache and nausea. 

 The cases are strikingly similar to the milder forms of influenza. 

 The first carefully observed epidemic in this country occurred in 

 Boston in 1911, and was epidemiologically studied by Winslow. 59 

 There were 48 fatal cases in the Boston epidemic. Since that time 

 a number of similar epidemics have been described, one of the most 

 extensive being that which took place in Chicago in 1911 and was 

 studied by Capps and Miller, 60 and by Davis and Rosenow. 61 In 

 the Chicago epidemic there were 10,000 cases, hardly any of which 

 came from the west side of the city. The relationship to the milk 

 supply was carefully studied. Of 622 cases investigated, 87 per cent 

 or 537 used milk from a certain dairy, and 79 per cent of the fatal 

 cases used the same milk. People taking milk from this dairy were 

 fourteen times more numerous than those getting it from other 

 sources. Of 153 nurses in a certain hospital using the milk, 80 per 

 cent got the disease, while of 721 in other hospitals, only 4.8 per cent 

 came down. There was a coincident epidemic of sore throats among 

 the employees of the dairy where bovine mastitis was found in the 

 cows. In fact, almost 5 per cent of the cows of this dairy had 

 mastitis, and streptococci were isolated from the milk of a cow 

 and from the throat of a girl on the same farm. Davis and Rosenow 

 describe the organisms isolated from these cases. In all of them 

 they found a streptococcus which produced large colonies on blood 

 agar, larger than the ordinary hemolytic organisms. There was 

 moderate hemolysis, and the organism was virulent for guinea pigs, 

 mice and rabbits. Capsules were developed on animal passage. 

 They believed their organism, which they called streptococcus epi- 

 demicus, to be a distinct species. However, Davis, in a subsequent 



59 Winslow, Jour. Infec. Dis., 10, 1912, 73. 



80 Capps and Miller, Jour. A. M. A., 58, 1912, 1848. 



61 Davis and Eosenow, Jour. A. M. A., 58, 1912, 773. 



