Susceptibility of Man. 627 



In general, bovine bacilli seem to have little tendency to spread 

 in the human body, usually causing local disease at the point of in- 

 fection and the neighboring tissues (mesenteric and cervical glands), 

 but in some cases the disease may become generalized. 



In regard to the frequency of primary intestinal infection and 

 its relation to the ingestion of tuberculous milk, reliable data have 

 as yet not accumulated in sufficient quantity. In the past too little 

 attention has been paid to this form of disease and besides, there is 

 no definite agreement as to the exact characteristics of primary in- 

 testinal tuberculous disease. While, for instance, some authors recognize 

 only primary intestinal ulcers as such, others, and probably correctly 

 so, regard the primary affection of the mesenteric glands with intact 

 intestinal mucous membrane also as such. According to modern views 

 in regard to the pathogenesis of tuberculosis (see p. 526) many cases 

 of primary tuberculosis of the thoracic and cervical glands as well 

 as scrofulosis must be looked upon as the result of primary intestinal 

 infection. The variable conceptions of this question is a sufficient 

 explanation of the conflicting statistical reports. While, for example, 

 Koch regarded primary intestinal infection (intestinal ulcers) as very 

 rare, and Baginsky noted only 10 such cases in the course of five 

 years in the Charite Hospital in the city of Berlin, Heller reports 

 37.8% of primary intestinal infection in post-mortem examinations 

 of tuberculous children in Kiel; Hueppe 25 to 35% in Prague; Council- 

 man 37.1% in Boston; Wagener, Eder and Ipsen in Kiel, Berlin and 

 Copenhagen, report 44 cases in 289 bodies of children examined. Ac- 

 cording to Ashby and Woodhead 70% of children that die of tuberculosis 

 show affection of the mesenteric glands. 



Weber, in a statistical report authorized by the German Imperial 

 Board of Health, shows that among 360 persons, among them 151 

 children, who had consumed raw milk and dairy products from 

 69 cows affected with tuberculosis of the udder the presence of "pearl 

 disease" could be demonstrated in only two of the children (tuber- 

 culosis of the cervical glands). This result by no means harmonizes 

 with the fact that the numerous authenticated cases of tuberculosis 

 in human beings, demonstrated to be caused by bacilli of the bovine 

 type have in most instances been tuberculosis of the glands in children 

 that had evidently been infected by the milk of tuberculous cattle. 



Constancy of Virulence of Tubercle Bacilli. The virulence of 

 the different types of bacilli seems to be very constant. It has always 

 been a difficult matter to change this artificially. Although according 

 to Orth, Hamilton, Karlinsky, Hamilton & M'Laughlan Young the 

 passage of human bacilli through cattle, according to v. Behring, 

 Karlinski, DeJong and Dammann & Muessemeier the passage through 

 goats and according to Mohler the passage through cats and rabbits 

 increases the virulence for cattle, experiments made by the German 

 Imperial Board of Health gave negative results throughout. Thus 

 Weber, in particular, was unsuccessful in increasing the virulence of 

 the human type of tubercle bacilli by five or eight consecutive passages 

 through goats, the passage of 15 strains through pigs for a period 

 extending over 300 days, and by four consecutive passages through 

 cattle for a period of 685 days. This type also fully retained its cultural 

 characteristics.^ Jancso & Elfen in their experiments with 18 strains 

 of human bacilli to increase their virulence for chickens by passage 

 through fowls, or their virulence for rabbits by passage through the 

 latter animals, obtained negative results. 



