MILK AND ITS RELATION TO THE PUBLIC HEALTH 609 



Milk and Its Relation to the Public Health. The importance of 

 milk as a medium for the transmission of pathogenic bacteria is shown 

 in the following list transcribed from the compilation of Trask. 1 

 Statistics of 317 epidemics of typhoid fever, 125 epidemics of scarlet 

 fever, 51 epidemics of diphtheria and 7 of septic sore throat are set 

 forth therein. This list is by no means regarded as complete; it 

 includes only those epidemics of recent years in which satisfactory 

 evidence of the origin and spread of disease is available. 



Milk that is free from frankly pathogenic microorganisms is not 

 necessarily a suitable food for man; it may be deadly for young 

 children and infants. In the past little was definitely known of the 

 relation of market milk to the high death rate among children, although 

 a very direct connection was suspected. Park and Holt, however, 

 made an extensive study of this very important question and their 

 results are illuminating. Their plan was to feed ten groups of children 

 with milk of known origin; this milk was mixed to secure uniformity 

 and divided into ten portions. One-half, containing about 1,200,000 

 bacteria per cubic centimeter at the time of feeding, was distributed 

 to one group; the other half was pasteurized before delivery. It 

 contained, on the average, about 50,000 viable bacteria per cubic 

 centimeter. The observations were carried on during the three 

 warmest months of the year. Within a week nearly two-thirds of the 

 infants fed with raw milk developed mild or severe diarrhea; about 

 25 per cent, remained well. Of those receiving pasteurized milk about 

 25 per cent, developed diarrhea and 75 per cent, remained well. A 

 similar experiment was made the following summer. Their conclu- 

 sions were: 2 



"1. During cool weather, neither the mortality nor the health of 

 the infants observed in the investigation was appreciably affected by 

 the quality of the market milk or by the number of bacteria which 

 it contained. The different grades of milk varied much less in the 

 amount of bacterial contamination in winter than in summer, the 

 store milk averaging only about 750,000 bacteria per cubic centimeter. 



"2. During hot weather, when the resistance of the children was 

 lowered, the kind of milk taken influenced both the amount of illness 

 and the mortality; those who took condensed milk and cheap store 

 milk did the worst and those who received breast milk, pure bottled 

 milk and modified milk did the best. The effect of bacterial contam- 



1 Bulletin 41 of the Hygienic Laboratory, Washington, D. C., January, 1908. 



2 Park and Holt, Arch. Pediat., December, 1903, 881. 



39 



