Probably many persons pass through an attack of pulmonary tuberculosis without knowing it; whether by virtue of resistance, or by mildness of invasion, they suffer comparatively little, and their peril is not recognized. They are off colour for a while, or over-worked or have a troublesome catarrh from which they recover.
From the eugenic standpoint a distinguished medical writer states in a recent article I would oppose the too frequent assumption that the victims of tuberculosis are after all weaklings whose weeding out, if painful to their friends, is on the whole good for the stamina of the race. It is true that by inheritance or by privation a person may be so debilitated as to offer a lessened resistance to any injurious influence from without, but on the other hand, in respect of tubercle, such a lack may mark a family from generation to generation as a peculiarity rather than as a frailty; or, at worst, as a flaw which is open to one kind of stress only. Such a constitution is a lock which may be shut to every key but one. Bar the tubercle and such an one may continue strong and beautiful.
(Sir T. Clifford Allbutt, Practitioner, January, 1913.)
The human race is, as a whole, remarkably susceptible to infection by the tubercle bacillus, and the same holds good for domestic animals. Individual difference in susceptibility are, however, very marked. The existence of tuberculous families is one of the cardinal facts of clinical medicine. It may be that a part of this familial incidence to tuberculosis is explained by similarities in the life and environment of the various individual members of the family, allowing of the same sources of infection, but this cannot explain the undoubted prevalence of tuberculosis in parents, brothers and sisters, where the family is scattered – a circumstance commonly seen. There is a tissue susceptibility, a favourable soil, that constitutes a potent element in the pathology of the disease. The essence of this predisposition is at present unknown to us.
Regarding the problem of inheritance, we now take a very different view from that which was adopted a generation or so ago. At that time inheritance was regarded as perhaps the most important factor in the causation of tubercle. What undoubtedly is inherited is a diminished resisting power to infection. Congenital tuberculosis is little more than a curiosity.
Resistance to tuberculous invasion then is greater in some persons than in others. It is definitely lessened in those descended from a tuberculous stock. It is again definitely lowered by conditions of depressed health, from certain chronic disease, from evil habits, and from bad sanitation.
Unquestionably from time to time nearly everyone is exposed to infection by tubercle bacilli, but fortunately, in the great majority of instances, they find no particular part in an unhealthy condition, and consequently sooner or later succumb to the defensive forces of the body. We must not wholly forger, on the other hand, the influence of a certain degree of acquired racial immunity due to the selective removal, through the centuries of civilization, of the least resistant persons and families. In a relatively new community of persons, who have formerly led more or less nomadic lives, and have never been exposed to infection, the tuberculous virus will spread like fire through the stubble.
How do the bacilli get into the body? In nearly all cases, either by inhalation or ingestion. The former mode of entry is commoner in adults, the latter in children. Essentially the food which is dangerous is milk. In London, and other large cities, something like ten per cent, of the samples of milk taken at random contain tubercle bacilli. Unfortunately, an enormous number of cows in all parts of the world are tuberculous-possibly not less than twenty per cent to thirty per cent of all dairy cows, and probably nearly two per cent in this country, suffer from tuberculous udders.
Tubercle bacilli have actually been found in the dirt under the finger nails of school children; how much more are they likely to be present in the dirt on the fingers of a baby crawling upon a dirty room or pavement? – the little child inhabits the floor.
The main entrance then, of the bacilli, is either by the mouth or the nose. Having obtained entrance, they are brought at once into contact with a mucous membrane. Vast numbers are doubtless destroyed by the mucous membranes; but if the latter should be in an unhealthy condition local infection may be set up. Moreover, it is undoubtedly possible for the bacilli to pass through a mucous membrane without causing any obvious local lesion. Possibly they may pass directly into the bloodvessels, but the larger number enter the lymphatics and so get conveyed to the nearest lymphatic glands. Here again, they may be destroyed; but if a gland is in a unhealthy condition, or if the number of bacilli brought to it is overwhelming, tuberculous disease with the familiar results may follow. There is yet a third possibility, namely, that the bacilli may pass through the glands, just as they pass through the mucous membrane, without giving rise to any mischief, and so may eventually by these indirect channels reach the blood stream. If the bacilli entering the blood-steam be in very large numbers we may have a general infection. For this to occur it is probably essential that there should be some local depot or focus of disease, usually a softening caseous mass. We may compare what happens with what takes place under conditions of warfare. We hear often enough of the danger of a raid which may lead to damage by the enemy, in a certain district or local area; but this would never suffice by itself for the conquest of a large country. Such a raid may be compared with the possible result of a limited number of tubercle bacilli obtaining entrance accidentally into the circulation. If, however, the country is to be conquered, the enemy must establish a definite base or centre from which it can operate and overspread the entire country. This is what occurs as a necessary precursor of a general blood infection. From a caseous focus, in which softening is taking place, enormous numbers of bacilli escape into the blood-stream, the resistant powers of the body are overcome, and general miliary tuberculosis follows. A softening caseous mass in any part of the body may serve as a centre for a generalized infection. It may be tuberculous disease of a bone, a joint, the middle ear, or occasionally of the glands of the neck. We must recognize the very important fact that local conditions greatly favour the development of tuberculous lesions in deep seated parts. There seems to be no doubt that when the vitality of an organ or part of the body is diminished by an injury, any bacilli which may be circulating in the blood-stream, and in time would otherwise probably have been destroyed find a favourable soil upon which to develop. Secondly we realize the importance of pre-existing morbid states, and unhealthy conditions, not only of the bones, joints, kidneys, etc., but also of the lymphatic glands. If the organs and tissues of the body are healthy they resist stray tubercle bacilli which may be present in the blood. If they are diseased from any cause whatever, such bacilli are only too likely to find a lodgment.
The lesions produced at various parts of the body when infection has taken place need not be described here, suffice it to say they may occur in any organ.
The symptoms of the disease appear to be due almost entirely to the operation of the intercellular toxins of the bacillus, and this poison is quite virulent after the microbe has been killed, for if dead bacilli are injected into susceptible animals their solution by the tissues leads not only to the formation of actual tubercles, but to many of the symptoms of tuberculosis; indeed, the animal may waste and die.
The question is still not finally decided whether tubercle bacilli can be transmitted to a child in the mother’s milk. Whether this be so or not, the practical point to bear in mind is that, if the mother is tuberculous, the sooner after the birth the child is separated from her the better. It has been recognised for a long time that a tuberculous mother should not be allowed to suckle her c Lactation has been forbidden mainly perhaps for the sake of the mother, but we must recollect that the prohibition is equally in the interest of the baby.
TREATMENT. – All measures tending to improvement of dwellings, to more accessibility to sun and air, lessened crowding of tenements, better food and clothing, and increased cleanliness in and about houses, are measures against the prevalence of tubercle. It can truly be said that the decline in the tuberculosis mortality of the last sixty years has been a steady one, dependent mainly upon an improvement in general hygiene, increased well-being, and cleanliness.
The efforts made towards the cure of tuberculosis and towards its prevention fall into two main groups (I) efforts aimed at raising the general resistance of the patient by a variety of means so that his tissues are able to repel more successfully the attacks of the bacillus and (2) efforts aimed at preventing the infection or reinfection of the body by the bacillus, and when the body is already infected, encouraging the formation of prophylactic substances.
LICENTIATE OF THE ROYAL COLLEGE OF PHYSICIANS; MEMBER OF THE ROYAL COLLEGE OF SURGEONS; LICENTIATE IN MIDWIFERY, LONDON AND EDINBURGH, ETC. PHYSICIAN TO THE READING AND BERKSHIRE HOMOEOPATHIC DISPENSARY.
Author of "The Stepping Stone to Homeopathy and Health,"
"Manual of Homoeopathic Treatment". Editor of "The Homoeopathic World."