TUBERCULOUS MEAT AND ITS CONSEQUENCES.

Woodville Examiner, Volume VII, Issue 659, 30 January 1891, Page 1 (Supplement)

TUBERCULOUS MEAT AND ITS CONSEQUENCES.

(nineteenth century.) Koch’s brilliant discovery of the bacillus has set at rest all doubt as to the cause of tuberculosis, and as to the question of its identity in man and the lower animals. No subject has more uninterruptedly engaged the attention of pathologists during the past twelve months, or is more likely to lead to results of the greatest practical importance. It has been discussed in the legislative assemblies of Europe and America with a view to the settlement of the manifold difficulties, legal and scientific, by which it is surrounded ; and public attention having been thoroughly roused to the gravity of the issues at stake, their solution is imperatively demanded in the interests alike of the large and important classes engaged in the supply of food to our markets, and the immeasurably larger and more important classes engaged in its consumption. The links in the chain of scientific evidence, based upon experiments conducted through a series of years, maybe thus formulated (1) Tuberculosis is caused by a minute vegetable organism, the bacillus; (2) this organism is identical in man and the lower animals, any slight apparent difference being purely morphological; (3) the disease is communicable from cattle to the human subject; (4) one of the most frequent methods of this communicability is the ingestion of the flesh of animals specifically affected ; and (5) the ordinary modes of cooking do not destroy the bacillus, and have absolutely no effect upon the spores which are the chief means of its propagation. Professor M'Fadyean stated before the Privy Council Commission that cooking can never be relied on as a sufficient preventive; ordinary cooking is insufficient to destroy the bacilli, and utterly incompetent to affect their spores, which require a much higher temperature to become devitalised; and all evidence shows that the usual cooking of joints of beef and other parts is not sufficient to raise them oven to 160 deg., the temperature at which blood coagulates, and therefore insufficient to destroy the bacillus; and Sir Charles Cameron, Mr. Lingard, and Professor M‘Call, experts of the highest authoruy, examined on the same occasion, confirmed this opinion. The medical officers of the Local Government Board in their last report concur in the tenacity with which the spores resist all destructive agencies, to the extent indeed that no known process is competent to deprive them of vitality; and the committee of the North of Ireland branch of the British Medical Association state that the heat to which the inside of a large roast is raised is insufficient to destroy infestivity. The growth of a bacillus may be arrested at a temperature below 82deg., but it does not die: it can be slowly killed by being subjected for several weeks to a temperature of 107‘oJeg., and dies if exposed to boiling point for half an hour; hut a shorter exposure to this heat fails as a hacillicide, for in sixty-two experiments with tuberculous flesh soaked in boiling water for ten to fifteen minutes, positive results as to infection by feeding were produced in 35 per cent. So great, indeed, is the vitality of the bacillus that Koch stillobtained the active microbe after conveying it through thirty-four generations of culture, for a time extending over twenty-two months; and the spores, the committee add, are far more tenacious of life. That the bacillus resists the action of the gastric juice and other fluids of the alimentary canal was first demonstrated by MM. Strauss and Wurtz, and later investigations have confirmed the results at which they arrived. Dr. Coats, the pathologist to the Royal Western Infirmary of Glasgow, says “That the juices of the alimentary canal are proved not to be fatal to the bacillus is shown by the frequency of tuberculosis of the intestines following tuberculosis of the lungs.” It might, then, be thought that if the bacillus had resisted the effects of cooking and of the fluids of the alimentary canal, no further impedimenta existed, and it would be at liberty to pursue its career unchecked, secrete its specific virus, and propagate its kind in the tissues. But happily this is by no means the case, and it is chiefly after its entrance, together with the products of digestion, into the lymph and blood streams that its struggle tor life commences. AVe are but at the threshold of our knowledge of this subject, one of the most deeply interesting of the problems of pathology, and one which holds out the brightest hopes of our ultimate success in dealing with the large and deadly class of specific diseases. AVherever the bacillus comes in contact with these wandering cells, whether prior to or after its entrance into the stream of the circulation, or when it has succeeded in effecting a lodgment in any of the tissues, a struggle takes place between the contending hosts, on whose result depends the issue of life or death to the part—eventually it may be to the entire body. In some cases, happily the great majority, where the constitution is unimpared, the result is favourable to the cells and the bacillus perishes; in others, where the tissues are weakened and the phlagocytes share in the debilitated condition—whether produced by heredity or any depressing cause the bacillus triumphs, finds a nidus suitable to the needs of its existence, propagates its kind and leads to the development of a tubercular leison. How constantly this struggle is being waged may be conceived from the fact that it has been calculated by Bollinger that one phthisical person may eject from his body in the course of twenty-four hours twenty millions of the bacilli. It may, then, ho taken as proved that the bacillus in all cases is derived by one animal from another, and grows only at a temperature approaching that of the human body; its chief if not its only place of multiplication is in the living tissue, and when it has found a suitable resting-place it commences its mission, propagating by spores and by fission, and secreting alkaloids dangerous to animal life, and leading to an alteration in the normal structure by the formation of tubercles, such lesions being an absolutely characteristic sign of the disease.