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NA TURE 



[JULV 25, 1 90 1 



bovine tuberculosis were found on the omentum and peritoneum. 

 In short, the cattle proved just as susceptible to infection by 

 the bacillus of bovine tuberculosis as they had proved insuscep- 

 tible to infection by the bacillus of human tuberculosis. I wish 

 only to add that preparations of the organs of the caitle which 

 were artificially infected with bovine tuberculosis in these 

 experiments are exhibited in the Museum of Pathology and 

 Bacteriolojiy. 



An almost equally striking distinction between human and 

 bovine tuberculosis was brought to light by a feeding experiment 

 with swine. Six young swine were fed daily for three months 

 with the tubercular sputum of consumptive patients. Six other 

 swine received bacilli of bovine tuberculosis with their food 

 daily for the same period. The animals that were fed with 

 sputum remained healthy and grew lustily, whereas those that 

 were fed with the bacilli of bovine tuberculosis soon became 

 sickly, were stunted in their growth, and half of them died. 

 After three months and a half the surviving ssvine were all killed 

 and examined. Among the animals that had been fed with 

 sputum no trace of tuberculosis was found, except here and 

 there little nodules in the lymphatic glands of the neck, and in 

 one case a few grey nodules in the lungs. The animals, on the 

 other hand, which had eaten bacilli of bovine tuberculosis had, 

 without exception (just as in the cattle experiment), severe 

 tubercular diseases, especially tubercular infiltration of the greatly 

 enlarged lymphatic glands of the neck and of the mesenteric 

 glands, and also extensive tuberculosis of the lungs and the 

 spleen. 



The difference between human and bovine tuberculosis ap- 

 peared not less strikingly in a similar experiment with asses, 

 sheep and goats, into whose vascular system the two kinds of 

 tubercle-bacilli were injected. 



Our experiments, I must add, are not the only ones that have 

 led to this result. If one studies the older literature of the 

 subject, and collates the reports of the numerous experiments 

 that were made in former times by Chauveau, Giinther and 

 Harms, Bollinger and others, who fed calves, swine, and goals 

 with tubercular material, one finds that the animals that were 

 fed with the milk and pieces of the lungs of tubercular cattle 

 always fell ill of tuberculosis, whereas those that received human 

 material with their food did not. Comparative investigations 

 regarding human and bovine tuberculosis have been made very 

 recently in North America by Smith, Dinwiddle and Frothing- 

 ham, and their result agreed with that of ours. The un- 

 ambiguous and absolutely conclusive result of our experiments 

 is due to the fact that we chose methods of -infection which 

 exclude all sources of error, and carefully avoided everything 

 connected with the stalling, feeding and tending of the animals 

 that might have a disturbing elTect on the experiments. 



Considering all these facts, I feel justified in maintaining that 

 human tuberculosis differs from bovine, and cannot be trans- 

 mitted to cattle. It seems to me very desirable, however, that 

 these experiments should be repeated elsewhere, in order that 

 all doubt as to the correctness of my assertion may be removed. 

 I wish only to add that, owing to the great importance of this 

 matter, the German Government has appointed a commission to 

 " make further inquiries on the 6\«bject. 



But, now, how is it with the susceptibility of man to bovine 

 tuberculosis ? This question is far more important to us than 

 that of the susceptibility of cattle to human tuberculosis, highly 

 important as that is too. It is impossible to give this question 

 a direct answer, because, of course, the experimental investiga- 

 tion of it with human beings is out of the question. Indirectly, 

 however, we can try to approach it. It is well known that the 

 milk and butter consumed in great cities very often contain large 

 quantities of the bacilli of bovine tuberculosis in a living con- 

 dition, as the numerous infection-experiments with such dairy 

 products on animals have proved. Most of the inhabitants of 

 such cities daily consume such living and perfectly virulent 

 bacilli of bovine tuberculosis, and unintentionally carry out the 

 experiment which we are not at liberty to make. If the bacilli 

 of bovine tuberculosis were able to infect human beings, many 

 cases of tuberculosis caused by the consumption of alimenta 

 containing tubercle-bacilli could not but occur among the in- 

 habitants of great cities, especially the children. And most 

 medical men believe that this is actually the case. 



In reality, however, it is not so. That a case of tuberculosis 

 has been caused by alimenta can be assumed with certainty 

 only when the intestine suffers first — i.e., when a so-called 

 primary tuberculosis of the intestine is found. But such cases 



NO. 1656, VOL. 64] 



are extremely rare. Among mar>y cases of tuberculosis 

 exammed alter death, I myself remember having seen primary 

 tuberculosis of the intestine only twice. Among the great /oj/- 

 >intr/em materia! of the Charite Hospital in Berlin ten cases of 

 priminary tuberculosis of the intestine occurred in five 

 years. Among 933 cases of tuberculosis in children at the 

 Emperor and Empress Frederick's Hospital for Children, 

 Baginsky never found tuberculosis of the intestine without 

 simultaneous disease of the lungs and the bronchial glands. 

 Among 3104 post worlems of tubercular children, Biedert 

 observed only sixteen cases of primary tuberculosis of 

 the intestine. I could cite from the literature of the 

 subject many more statistics of the same kind, all indubitably 

 showing that primary tuberculosis of the intestine, especially 

 among children, is a comparatively rare disease, and of these 

 few cases that have been enumerated, it is by no means certain 

 that they were due to infection by bovine tuberculosis. It is 

 just as likely that they were caused by the widely propagated 

 bacilli of human tuberculosis, ivhich may have got into the 

 digestive canal in some way or other — for instance, by swallow- 

 ing saliva of the mouth. Hitherto nobody could decide with 

 certainty in such a case whether the tuberculosis of the intestine 

 was of human or of animal origin. Now we can diagnose them. 

 All that is ntcess.iry is to cultivate in pure culture the tubercle- 

 bacilli found in the tubercular material, and to ascertain whether 

 they belong to bovine tuberculosis bv inoculating cattle with 

 them. For this purpose I recommend subcutaneous injection, 

 which yields quite specially characteristic and convincing results. 

 For half a year past I have occupied myself with such investiga- 

 tions ; but, owing to the rareness of the disease in question, the 

 number of the cases I have been able to investigate is but small. 

 What has hitherto resulted from this investigation dues not 

 speak for the assumption that bovine lubercul'osis occurs in man. 

 Though the impoitant question whether man is susceptible to 

 bovine tuberculosis at all is not yet absolutely decided, and will 

 not admit of absolute decision to-day or to-morrow, one is 

 nevertheless already at liberty to say that, if such a susceptibility 

 really exists, the infection of human beings is but a very rare 

 occurrence. I should estimate the extent of infection by the 

 milk and flesh of tubercular cattle, and the butter made of their 

 milk, as hardly greater than that of hereditary transmission, and 

 I therefore do not deem it advisable to take any measures 

 against it. 



So the only main source of the infection of tuberculosis is the 

 sputum of consumptive patients, and the measures for the com- 

 bating of tuberculosis must aim at the prevention of the dangers 

 arising from its dififasion. Well, what is to be done in this 

 direction? Several ways are open. One's first thought might be 

 to consign all persons suffering from tuberculosis of the lungs, 

 whose sputum containstubercle-bacilli, to suitableestablishments. 

 This, however, is not only absolutely impracticable, but also 

 unnecessary. For a consumptive who coughs out tubercle- 

 bacilli is not necessarily a source of infection on that account, so 

 long as he takes care that his sputum is properly removed and 

 rendered innocuous. This is certainly true of very many 

 patients, especially in the first stages, and also of those who 

 belong to the well-to-do classes, and are able to procure the 

 necessary nursing. But how is it with people of very small 

 means? Every medical ir^an who has often entered the dwell- 

 ings of the poor, and I can speak on this point from my own 

 experience, knows how sad is the lot of consumptives and 

 their families there. The whole family have to live in one 

 or two small, ill-ventilated rooms. The patient is left with- 

 out the nursing he needs, because the able-bodied mem- 

 bers of the family must go to their work. How can the 

 necessary cleanliness be secured under such circumstances ? 

 How is such a 'nelpless patient to remove his sputum, so that it 

 may do no harm? But let us go a step further and picture the 

 condition of a poor consumptive patient's dwelling at night. 

 The whole family sleep crowded together in one small room. 

 However cautious he may be, the sufferer scatters the morbid 

 matter secreted by his diseased lungs every time he coughs, and his 

 relatives close beside him must inhale this poison. Thus whole 

 families are infected. They die out, and awaken in the minds 

 of those who do not know the infectiousness of tuberculosis the 

 opinion that it is hereditary, whereas its transmission in the 

 cases in question was due solely to the simplest process of infec- 

 tion, which do not strike people so much, because the con- 

 sequences do not appear at once, but generally only after the 

 lapse of years. 



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