TTBEKCULOSIS 



1 1 



man. In support of the latter statement, Koch produced 

 statistics which were said to prove the great infrequency 

 of man's infection with tuherculosis through food. 



It is evident that the question of the identity or non- 

 identity of tuberculosis of man and cattle is of great 

 importance in the control of the milk supply. Koch, con- 

 sequently, drew the conclusion from his investigations 

 that tlic control of meat and milk, so far as tuberculosis 

 is concerned, is sui)erfluous and unnecessary. There- 

 fore, we have all the more reason for a closer consid- 

 eration of the three ([uestions placed in the foreground 

 l)y Koch's report. 



1. Is tuberculosis from food infection rare in man? 



'1. ('an human tuherculosis he transmitted to cattle? 



."). Can it be ]iroven that tubei-culosis of cattle is 

 transmissible to man? 



If we fii'st coiisidei' the (|uestion of the fre(iuenc>' of 

 the occurrence of tuliei-culosis in man from infection 

 tbrough his food, it will be seen at once that differences 

 of opinion exist concerning the modes of infection. The 

 usual oj)inion (until (|uite recently) is that by fai' the 

 greatest number of cases of tuberculosis in man are 

 caused by inhaling the dry bacilli; there is, however, 

 oj^position to this \\v\\. Ribbert and Aufrecht have 

 concluded that tubeiculosis of the lungs is of embolic 

 origin and others ((irawitz) have found the tonsils to be 

 among the most favorable i)laces for the admission of 

 bacilli. Observations on animals, particularly on swine 

 and monkeys, caution us not to draw definite conclusions 

 in relation to the mode of infection from the gross ana- 

 tomical lesions. Thus, for example, with swine that 

 are infected almost exclusively through the digestive 

 canal, tuberculosis of the intestines is an exception, 

 while miliary tuberculosis of the lungs often leads to a 

 rapidly develojiing caseous pneumonia. 



