BACTERIA IN MILK 705 



Diphtheria has been frequently traced to the use of infected milk. 

 In most of the epidemics reported as originating in this way, the proof 

 has been necessarily indirect. In two out of twenty-three epidemics 

 reported by Trask, however, Bacillus diphtherise was isolated from 

 the milk directly. The ability of the Klebs-Loeffler bacillus to proliferate 

 and remain alive for a long while in raw milk has been demonstrated 

 by Eyre ' and others. 



Whether or not cholera asiatica may be transmitted by means of 

 milk has been a disputed question. Hesse ^ claims that cholera spirilla die 

 out in raw milk within twelve hours. This statement, however, has not 

 been borne out by other observers.^ Unquestionable cases of direct 

 transmission of cholera by means of milk have been reported by a num- 

 ber of writers, notably by Simpson.* 



The relation of milk to the diarrheal diseases of infants has, of late 

 years, received a great deal of attention. In large cities, during the 

 summer months, numerous cases of infantile diarrhea among bottle- 

 fed babies occur, which, in many instances, are attributed to feeding with 

 contaminated milk. Park and Holt,^ who have made extensive re- 

 searches upon this question in New York City, have come to the con- 

 clusion that the harmful effects of contaminated milk upon babies 

 can not be ascribed to any given single microorganism in the milk. 

 Specifically toxic properties were found by these writers for none of the 

 one hundred and thirt3'-nine different species of bacteria isolated from 

 unsterilized milk. It is unHkely, therefore, that the diarrheal diseases 

 among babies have a uniform bacteriological cause. Whether or not 

 these diarrheal conditions depend entirely upon the bacterial contents 

 of milk or, in a large number of cases at least, upon the inability of the 

 child to digest cows' milk because of chemical conditions, must be left 

 undecided. Park and Holt, in analyzing their extensive data, conclude 

 that milk containing " over one million bacteria to the cubic centimeter 

 is certainly harmful to the average infant." 



The significance of the presence of streptococci in milk, as an element 

 of danger, has recently received much attention in the literature. Heine- 

 mann," who has made a careful comparison of Streptococcus lacticus 



1 Eyre, Brit. Med. Jour., 1899. 

 'Hesse, Zeit. f. Hyg., xvii, 1894. 

 ' Basenau, Arch. f. Hyg., xxiii, 1895. 

 « Simpson, Indian Med. Gaz., 1887. 

 ' Park and Holt, Arch, of Fed., Dec, 1903. 

 ^ ' Heinemann, Jour. Inf. Dis., 3, 1906. 



