6 
BULLETIN 342, U. S. DEPARTMENT OF AGRICULTURE 
Table 1. — Milk-borne outbreaks reported by State and city health officers of the 
United States for the years 1924 to 1930, inclusive 
Typhoid 34 
--old A 
r^ra: — ioidB 1 
Diphtheria 1 
Septic sore threat 
Scarlet iever 
Miscellaneous 
T-z-.-H 
i : r - : 
1 : _; 
>. 
During this 7-year period, the average number of milk-borne out- 
breaks reported per year is approximately 47. 
EXTENT OF PASTEURIZATION IN THE UNITED STATES 
The application of Pasteur's discovery to the milk industry was 
slow. The heating of milk was first done secretively and for the sole 
purpose of preserving the milk, thereby saving losses to milk dealers. 
Jaeobi, a noted American health authority, is believed to have been 
the first public-health expert to recommend the heating of milk: 
this was in 1889. The adoption of pasteurization by the cities came 
some vears later. Pasteurization of m il k was besrua in Cincinnati in 
1897, in Xew York, 1S9S: in Philadelphia, lS99?in St. Louis, 1900: 
in Boston and Chicago. 190S. Some firms would pasteurize but 
dared not admit it to the public. In 1906, Xew York City passed 
an ordinance prohibiting clandestine pasteurization, and in 1910 began 
to regulate the time and temperature of pasteurization. The increase 
in pasteurization was slow. Although in 1S92 the heating of milk in 
tenement homes was widely practiced. Jordan (il; states that only 
about 5 per cent of the milk supply of Xew York City was pasteurized 
by the milk dealer in 1903. Other sources of information show that 
by 1910. 25 per cent of New York's supply was so treated, and in the 
next two years the percentage increased to 40. Beginning in 1912, 
the amount pasteurized increased rapidly for a number of years. 
The Boston market was somewhat slower in starting: so little was 
pasteurized in 1902 that it was not reported. However, by 1910. 
50 per cent was being processed; and by 1915, SO per cent. These 
rapid increases were due to the fact that as the practice became more 
general much scientific study was given to the subject. These studies 
brought out the facts that pasteurization, when properly done, was 
not detrimental to the chemical and physical properties of the milk, 
and that it safeguarded the consumer by lolling pathogenic organisms. 
Table 2 is compiled from three questionnaires sent to health 
officials. In 1915 the figures were based upon 344 replies, in 1924 
upon 32S. and in 1930 upon 344. The 1930 figures represent reports 
from 46 States. 
