BOVINE TUBERCULOSIS 363 



national Congress at Washington, had evidently modified his stand- 

 point, which he then expressed as follows : 



"1. The tubercle bacilli of bovine tuberculosis are different from 

 those of human tuberculosis. 2. Human beings may be infected by 

 bovine tubercle bacilli, but serious diseases from this cause occur 

 very rarely. 3. Preventive measures against tuberculosis should 

 therefore be directed primarily against the propagation of human 

 tubercle bacilli." 



Since 1901 a great number of experiments have been made in 

 relation to the question of the difference in virulency between human 

 and bovine tubercle bacilli, the possibility of infecting cattle with 

 bacilli of human derivation, and presence or absence of bacilli of 

 the bovine type in human tubercular lesions. Those who followed 

 Koch and Schiitz did not confine themselves to human sputum 

 bacilli, but also chose tubercular material from other sources, and it 

 was soon found that such material sometimes contained bacilli of the 

 bovine type which are quite virulent to cattle. Kossel, Weber and 

 Heuss, after Koch's and Schiitz ' experiments, examined 56 cases of 

 human tuberculosis and found in 49 bacilli of the human type, in 

 5 bacilli of the bovine type, and in 2 bacilli of both types. The 5 

 cases in which they found bacilli of the bovine type were those of 

 children under five years of age, 4 of which warranted the conclusion 

 that the bacilli had gained entrance through the intestinal tract. 

 The 49 cases in which bacilli of the human type only had been found 

 included many forms of tuberculosis, such as tuberculosis of the 

 lungs, lymph glands, bones, joints, genito-urinary tract, intestinal 

 tract, peritoneum, and meninges, and general miliary tuberculosis. 

 The tubercular subjects were of all ages, and among them 2 cases of 

 tuberculosis of the peritoneum were found which anatomically were 

 of the "Perlsucht" type, but in which the bacilli were not of the bovine 

 type but the human kind. 



Weber, in the article on "Tuberculosis of Man and Animals," 

 in Kolle and Wassermann's Manual of Bacteriology, enumerates, 

 including his own, 14 cases of tuberculosis in man, collected from 

 literature, in which bacilli of the bovine type had been isolated beyond 

 doubt. Since the publication of his report several further cases have 

 been added to the list by Smith and Mohler and Washburn, and 

 perhaps by some others, but it is safe to say that there are not many 

 above 50 cases now on record, and none of these were cases of pul- 

 monary human tuberculosis. It appeared to be the general consensus 

 of opinion at the last International Congress on Tuberculosis that 

 Koch's contention was correct and that no case of human pulmonary 

 tuberculosis had yet been traced beyond doubt to the bovine tubercle 

 bacilli, because the few cases reported as such were not beyond 

 reasonable criticism. The cases of human tuberculosis shown to be 

 caused by bacilli of the bovine type are, as appears, all traceable to 

 the entrance of the bovine bacilli through the intestinal tract, probably 



