78 PRINCIPLES AND PRACTICE OF MILK HYGIENE 



type of the organism was determined by others, a total of 

 1511 cases. There were 955 cases in individuals over 16 

 years of age, 177 in children between 5 and 16 years, and 

 368 in children under 5. Tubercle bacilli of the bovine 

 type were found in 35 per cent, of the cases in children 

 between the ages of 5 and 16, and in 26 per cent, of the 

 cases in children under 5. In addition to these, there were 

 eleven cases in which both types of bacilli were found. 



It is usually difficult to discover the source of infec- 

 tion in cases of tuberculosis in man because the disease 

 does not become apparent for a long time after exposure 

 to infection has occurred. Nevertheless, there are a 

 number of cases recorded of tuberculosis in children and 

 adults using milk from tuberculous cows for which no 

 other source of infection could be found. 6 Regarding the 

 evidence in these cases as generally incomplete, Koch, in 

 1902, suggested that a search be made for cows in which 

 tuberculosis of the udder could be positively diagnosed 

 and, when such cases were found, that it be ascertained 

 how long the disease had existed, who consumed the milk 

 or its products, whether the milk was used raw or cooked, 

 and if the persons who used the milk or its products were 

 infected with tuberculosis. Between 1905 and 1909 

 Weber and Ungerman 7 found in Germany 69 cases of 

 udder tuberculosis concerning which the information de- 

 sired could be obtained. Three hundred and sixty per- 

 sons, including 151 children, used milk from these cows. 

 Two boys were affected with tuberculosis of the cervical 

 lymph glands in which bacilli of the bovine type were 



6 Rievel, Milchkunde, pp. 107-108. 



7 Cited by Ostertag, Zeitschr. fur Fleisch u. MilcKhygiene, 

 pp. 26 and 27, No. 2, vol. xxiii ; p. 123, No. 6, vol. xxiv. 



