Art. LXI.—Tuberculosis in Man and Animals.
[Read before the Wellington Philosophical Society, 11th October, 1893.]
The most distinctive feature in the practice of modern medicine is the public demand for, and the profession's willingness to impart, instruction in the nature and causes of disease. This is the natural outcome of the rise and progress of preventive medicine—a science pre-eminently the people's, for only when its truths are understood and appreciated by the public will the good fruits of this beneficent science be fully manifested. The practice of one hundred years ago was almost exclusively curative; but more real good has accrued to humanity, more disease has been controlled, and more happiness promoted by preventive measures in State medicine, and prophylactic treat-
ment in practice, than has resulted from the cures of a century.
Of all the diseases which come within the province of preventive medicine none bulks so largely in national importance as tuberculosis. Tuberculous diseases are the scourge of the British Isles, where scarcely a family is to be found that has not suffered directly or indirectly from this insidious foe. All civilised countries in temperate regions are afflicted by its ravages. It attacks its victims in the bloom of youth or in the flower of manhood, while those who are marked for its prey often show a clearness of intellect, a vivacity of character, and a loftiness of conduct much above the normal, making this disease responsible for the aphorism that “the good die young.”
Since Koch's discovery in 1882 of the bacillus of tubercle a complete revolution has taken place in our knowledge of tuberculosis. It is now held to be, and treated as, an infectious preventible disease, whose manifestations vary with—(1) the animal attacked, (2) the organ attacked, (3) the degree of infection.
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The cause of the disease is a minute vegetable organism belonging to the Schizomycetes, and known as the Bacillus tuberculosis. It is rod-shaped, 1/7000in. in length, and developes by the formation of spores. It flourishes best in dead or partially devitalised animal tissue, but when the disease is prevalent it abounds almost everywhere. The expectoration of a tuberculous man or animal contains millions of these organisms and their spores. After drying on pavements, floors, walls, or grass, the germs are carried about in the air, which is inhaled by others, or the grass may be eaten by stock previously free from infection. The presence of this minute organism in any of the body-tissues then constitutes tuberculosis; its absence makes the existence of the disease impossible; and it is this organism that has to be reckoned with in all public - health measures for the control of consumption. Rest, warmth, moisture, and nutriment are required in partially devitalised, non-resistent, or weakened animal tissue, to allow of a nidus being formed for the development of the bacillus. These conditions are found in the tops of the lungs of young people who restrain the functional activity of these areas by cramping the chest, especially if there is a constitutional weakness of the lung-tissue due to the disease having existed in the parents. In this sense only, it might here be remarked, is tubercular disease hereditary; the constitutional or tissue weakness is transmitted, and these weakened body-tissues become an easy prey to the invading bacillus. There is no direct transmission, though there may be maternal infection, and the child die in infancy.
The conditions necessary to successful invasion (rest, weakened tissue, &c.) are also present in the brain membranes of some young and weakly students—here tubercular meningitis arises; or in the knees of housemaids or men used to scrubbing floors—here “housemaid's knee,” or “white swelling,” arises; or the glands of the neck may be the seat of infection, or the bones of the spine, or the hip-joint, constituting the conditions known generally as spinal disease and hip disease respectively; or the lungs, the intestines, or the neck-glands in cattle may be affected, constituting bovine tuberculosis. In short, any part of the human body, or of the body of an ox, may become invaded by the bacillus of tubercle; and the want of uniformity in the nomenclature of the disease is due to the fact that the names were given before the true nature of the affection was understood.
It is not necessary to make reference to the destructive processes that go on after the invasion of the body-tissues by the bacillus of tubercle, as the purpose of this paper is to deal with the subject in its public-health aspect; and the points of importance in this connection are—(1) That tuberculosis is a germ disease; (2) that it exists in man and in some of the animals he uses for food; (3) that it is infectious, being communicable from man to man and animal to man; (4) that, being infectious, it is preventible; (5) and, being preventible, it comes within the province of State medicine.
First, then, tuberculosis is infectious; but the infection is not virulent, the vitality of the bacillus is low, and the conditions necessary to successful invasion are numerous; while the power of immunity, or resistance to infection, is an increasing factor in healthy individuals. But, apart from the bacterial nature of the disease, and the truth of the statement that diseases of germ origin are all more or less infectious, instances of direct infection are constantly under notice. Individuals in the same house are infected by each other; successive families following one another as tenants of the same house have fallen victims to the disease; and such houses have been known to be infected for generations. Respired air, or air vitiated by germs from dried expectoration, is the medium by which infection is conveyed in such places. The air in hospitals for consumptives has been found to contain the tubercle bacillus, and to have the power of inoculating nutritive media, from which the disease has been produced experimentally.
The milk and flesh of affected cattle form another, and perhaps the most important, medium by which the disease is communicated to man. That these tissues contain the bacilli of tuberculosis has been frequently demonstrated, and the disease has been produced experimentally through their agency.
The question of the degree of infective power of the tissues of an animal with only a local tuberculosis—for instance, diseased glands—is still unsettled, and forms the subject of a Royal Commission of the House of Commons now investigating the matter; but the Public Health Acts in England and Scotland assume that where a local tuberculous centre exists any and all of the body-tissues are infective. Of these tissues milk is by far the most dangerous, for it is used in the raw state, and most largely by children, who are susceptible to the disease in all its forms; and the frequency with which tuberculous symptoms manifest themselves soon after weaning has been urged as evidence of infection by milk.
It is certain, and is universally admitted, that a large amount of tuberculous disease is communicated to children by infected meat and milk, and the Health Acts of Britain are built upon this knowledge. Quite recently a butcher in the South of England was fined £30 and £7 costs for exposing meat from a diseased beast for sale. The penalties for this offence under all up-to-date Health Acts are very severe, and rightly so, for no one knows better than a butcher when he is dealing with infected meat, for every slaughter is a postmortem examination, and every butcher is, or ought to be, familiar with the indications of disease.
So well recognised in Britain is the infectiousness of tuberculosis that at the annual Congress of the British Institute of Public Health, held in Edinburgh last month, Dr. G. E. Squire, of London, read a paper entitled “Should Pulmonary Consumption be included in the Notification Act?” in which he urged that this step is necessary to control the spread of this disease, and was supported in his contention by many distinguished health officers.
Amongst cattle themselves grass very readily gets infected by expectoration, discharge, and excreta, and the communicability amongst stock is very marked, and manifest to all breeders. About two years ago, when spending a short holiday in Taranaki, I was induced by my friend Mr. York, of the Hawera Star, to examine several young cattle said to be “wasters”—a name given by the farmers to those animals that, for no obvious reason, suddenly began to waste away, and to eventually die. There was absolutely no evidence of disease upon a casual examination of three two-year olds I specially examined; they simply looked ill-fed and half-starved. I was assured that they had come from good paddocks, that their fellows were sleek and fat, and that from past experience these young beasts were doomed to waste away and die. A butcher dissected up these animals for me, and I found that, though, all the other organs were apparently healthy, the intestines, on being opened, were studded with
small tuberculous ulcers throughout. This cleared up the mystery of these “wasters.” Young stock feeding on infected grass developed intestinal tuberculosis, nutrition was interfered with; the disease once established was practically incurable, and the unfortunate animals, after living long enough to spread the infection widely, gradually sank and died. Upon the suggestion of Mr. York I delivered a lecture at Hawera upon the nature and preventive treatment of tuberculosis, and was told subsequently that within a fortnight fifty head of suspected stock were killed by the owners themselves.
From a return* very kindly prepared for me by Mr. Von Dadelszen, showing the relative mortality from tuberculous diseases in New Zealand for the years 1882 and 1892, I find that while, on the whole, the amount, of disease has decreased, the deaths from tuberculosis in Taranaki and Hawke's Bay have increased. In Wellington, Nelson, Westland, and Otago the mortality has remained about the same; while in Auckland, Marlborough, and Canterbury it has considerably abated.
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|Mean European Population.||Number of Deaths from Tubercular Diseases.a||Proportion per 10,000 of Population.||Mean European population||Number of Deaths from Tubercular Diseases.||Proportion per 10,000 of Population.||Phthisis.||Other Tubercular Diseases.a|
|Rate per 10,000 from tubercular diseases||28·9|
[Footnote] * Mortality in New Zealand from Tubercular Diseases.
[Footnote] a Includes tabes mesenterica, tubercular peritonitis, tubercular meningitis, acute hydrocephalus, phthisis, scrofula, and other forms of tuberculosis.
This disease, then, can only be controlled by preventive measures, and these may be divided into individual prevention and State prevention. Under individual prevention such precautions should be taken as the destruction of all sputa by burning, the comparative isolation of phthisical patients, the thorough purification of apartments used by such, the boiling of suspected milk, and the thorough cooking of suspected meat. The natural resistance of the body-tissues of all young and growing people should be increased by chest exercises, such as singing, rowing, and varied gymnastics; while hygienic laws should be thoroughly and consistently taught in all schools, and be allowed to replace much of the rubbish now crammed into young heads.
State legislation can and should be made a most important factor in the control of this much-dreaded disease. State enactments for the prevention of disease are amongst the proudest advances in modern legislation, and the Public Health Act of London, 1891, is a triumphant monument to the life and labours of members of a noble profession, and to wise and philanthropic legislators, who have eagerly seized upon their scientific discoveries and embodied them in humane enactments for the diminution of suffering, the promotion of happiness, and the public good. When we think of what medical science has done for London alone we wonder at the few there are who give her thanks. She has given to the lowly habitations of this great city the light of the sun and the pure air of heaven; she has led sparkling water from the hillsides to the meanest homes; she has pulled down the hovels of the poor and built them palaces; she has cleansed her streets and put guardians in her gates; she has banished typhus, controlled small-pox and cholera, and poured the balm of Gilead into a million wounds; she has saved the health and life of countless numbers, and exceeded every other humane factor in her contribution to the cup of human happiness. And all this through the agency of public-health legislation.
But very much still remains to be done, and could more readily be accomplished if there were a closer bond of unity between medical science and legislation; and the want of this is not the fault of the former, for science prays and beseeches long and patiently before her haughty sister will condescend to listen.
Perhaps in no part of the world is public health so well and extensively administered as in England and Scotland; and there is now a well-founded and growing demand for a Government Department of Public Health, with a Minister at its head. At no distant date the Mother-country will have accomplished this great reform. Our New Zealand Govern-
ment boasts that it leads the world in Liberal legislation, but it is far behind other countries in the matter of State medicine.
Nothing but legislative interference—compulsory, not permissive legislation, which is a farce—will protect the public of New Zealand from the danger that exists from the alarming amount of tuberculosis at present to be found amongst stock. And more especially is this an urgent question for Wellington, which gets some, at least, of its beef and butter from the most infected districts in the colony. And the legislative remedy is not a difficult nor a complex problem: the establishment of public abattoirs, the licensing and thorough inspection of all dairies, with adequate penalties for offences against the Act, would satisfy the demands of public health, as it does in other parts better off than ourselves for hygienic laws; and it will not redound to the credit of our legislators if, in the face of an abundant knowledge on the subject, the health and life of the people are not protected by useful legislation in this direction.
The London Model Abattoir Society has done much to popularise the public slaughter-house system; and its reports, gathered from the experience of about fifty towns in England and Wales, clearly show that the abattoir system is the only means by which the sale of diseased meat can be absolutely controlled. By this system a public slaughter-house is established on the outskirts of the city by either the municipality or a private company. The buildings generally consist of sale-yards and slaughter-yards, conveniently arranged and paved throughout, with every provision for the humane treatment of the animals to be slaughtered. In the best managed provision is made for the immediate boiling, preparation, or disposal of all readily decomposable material, and an abundant supply of water at high pressure insures thorough cleanliness throughout. It is at these abattoirs only that thorough inspection can be practised, and this is done by competent meat-inspectors, who either stamp or certify to the wholesomeness of the meat sent to the retailers, and it is made a punishable offence for any meat to be conveyed or exposed for sale within the municipality that has not been certified to. A small fee is charged for the use of these abattoirs, and as a rule they clear expenses—some pay well, and very few indeed are worked at a loss.
The advantages of the abattoir system are: (1.) It is the gateway through which all animal food must pass to the consumer, and at which it must receive the certificate of a qualified meat-inspector. (2.) Efficient inspection of a large number of private slaughter-yards, scattered round the town, is costly and practically impossible. (3.) Provision can more
easily be made for roofed sheds, paved floors, water-flushes, ample feeding, and humane treatment generally. (4.) Weight and time are economized, as the abattoir can be situated at some convenient place, and driving be saved. (5.) Nuisance can be effectually prevented. (6.) Consumers have a guarantee that they are being supplied with only sound and healthy meat.
In conclusion, it must be urged that the State has a twofold duty in the domain of hygiene—a duty to itself and a duty to its subjects individually. Health is wealth to the State, as to the individual, and every day's sickness is a national loss. It is wise for the State to invite and encourage a healthy immigrant, but it is equally wise, and infinitely more humane, to restore a sick man to health, while it combines these qualities with that of commendable forethought if it prevents a man from contracting disease.
But it is the bounden duty of the State to have a watchful care over the health of its subjects for the sake of humanity and posterity, as well as for the sake of present policy; and it is not too bold to say that a few wise laws, based on modern hygiene, and enacted by our next Parliament, would save many valuable lives, and promote a degree of health and happiness that would remain an abiding blessing.