Volume XIX

“B

UT nothing is more estimable than a physician, who, having studied Nature from his youth, knows the properties of the human body, the diseases which assail it, the remedies which will benefit it, exercises his art with caution, and pays equal attention to the rich and poor."-VOLTAIRE.

The pioneers in our knowledge regarding infectious diseases have all been great students of natural history. The greatest intellect of all was that of Pasteur, the French savant who paved the way to all our knowledge in bacteriology and immunology. To-day Pasteur's investigations and discoveries in diseases of silkworms and in chicken cholera are the foundations of much that is being done to combat tuberculosis.

Koch, to whom we owe the discovery of the tubercle bacillus and of originating valuable immunity experiments, was all his life a great student of nature; so also was Laennec, to whom we owe the first clear conception of this disease, as well as the introduction of the stethoscope.

"Fix'd like a plant on his peculiar spot To draw nutrition, propagate and rot."-POPE. The life history of the tubercle bacillus is not yet completely known. For any intelligent campaign against this parasite, however, we must try to obtain all the knowledge we can of the "aspirations" and of the "militarism" of this annual destroyer of upwards of one million of the world's people.

The tubercle bacillus probably does not wish to kill the subject it gets access to, but only to use the victim as a colony where its "militarism" may be developed, its "place in the sun" secured, and egress may be had to other "colonies" or victims. Should a victim die a "colony" is lost. A "colony" of the tubercle bacillus constitutes a "carrier."

No. 3

In studying the epidemiology of diseases, more and more evidence has developed that "carriers" exist, and are the chief causes of propagation of most of the infectious diseases. Pasteur, in studying chicken cholera, was the first to suggest this idea of "carriers" of disease. From inoculating guinea-pigs with chicken cholera virus, no general disease developed, only a local abscess formed which opened, drained and healed. After placing a guinea-pig, with such a running sore, in a pen with chickens, these animals were rapidly decimated by disease. Pasteur prophetically remarked, "How many contagious diseases in the future will be traced to similar conditions,”the creation of one infected victim, almost unharmed himself yet a "carrier," and the death and destruction of large numbers infected by him.

In our sanatorium work we, by aiding nature to arrest conditions of active tubercle, have been greatly increasing the numbers of "carriers" in the country at large, and in some degree aiding the tubercle parasite. Yet it has been a right humanitarian principle to care first for the unfortunate consumptive. Great emphasis in future must more and more be laid upon prevention and here we now know we must begin with the child.

"As man, perhaps, the moment of his breath, Receives the lurking principle of death, The young disease which must subdue at length Grows with his growth, and strengthens with his strength."-POPE.

These prophetic words of the poet Pope-so scientifically qualified by "perhaps"-well illustrate modern thought regarding tubercle infection. The idea was probably inspired as a result of tuberculosis of the spine with which Pope suffered as a child.

As you well know, practically all children

become infected with tubercle. Should such infection occur in the first three years of life, it is very apt to be quickly fatal. The highest death rate we have from this disease at any age period is actually in the first three years of life. At this time the fatal form is often tuberculous meningitis, a type which is of the greatest cause of sorrow to us, but useless to the parasite. A parasite must have access to and egress from its host, and it is only when the adult type of pulmonary tuberculosis has been achieved, and the tubercle bacillus is expectorated in countless millions, that the germ's cycle of development appears fulfilled. From four years of age, childhood tubercle infection is not apt to be so serious an affair, yet just as "the child is father to the man,' so such childhood infection in some will in time develop into the adult consumptive. I can not but believe that all childhood infection should be regarded as disease. While it is true that this infection becomes more or less extinct in time in the large majority, yet we are tracing more and more disorders of childhood such as anaemia, underweight, capricious appetite, digestive upsets, irritability of temper, slight daily fever, accelerated pulse, restlessness, and easy fatigue, to the tubercle poison. It is with great pleasure that I learn that one of the principal activities of the Arizona Anti-Tuberculosis Association this year will be the establishing of a preventorium for such children. Obsta principiis (Resist beginnings).-HORACE.

Inordinately difficult to estimate is the relative importance of heredity and family exposure in propagating tuberculosis.

Our

It is pretty clear, in spite of an occasional dissenting voice, that the children of the tuberculous too often develop the disease. records at Cragmor Sanatorium, in Colorado Springs, show a known and acknowledged positive family history in over 50 per cent. of the cases. We very often learn of the disease pursuing a family through three or more generations, and this among intelligent and careful people living in the best circumstances. Not infrequently investigation discloses that a parent or grandparent is an unsuspected chronic disseminator of tubercle bacilli.

Adams, in an endeavor to show that family tuberculosis is not common, reports the family history negative in 60 per cent. of cases-that is, positive in 40 per cent. Solis-Cohen speaks of securing positive family histories in a little more than 40 per cent. of a group of patients.

If an accurate general census could be made of all persons, regardless of the state of their health, approximately one in five, or 20 per cent., should give a history of tuberculosis in at least one parent, since about one person in ten dies of the disease. The additional percentage of those who are known to have tuberculosis, but recover and die from other causes, is small. The estimate may therefore fairly be based on the mortality percentage, doubled for the two parents. The figure would be increased by including other relatives besides parents, but is in reality reduced by lack of

knowledge and lack of candor in our patients. so that it is likely that the latter source of error more than balances the former. As a rough estimate, 20 per cent. may be taken as the approximate expectation of a family history of tuberculosis in the population at large.

We have, then, among the tuberculous a percentage of positive family histories more than double the normal expectation. The family grouping of the disease is striking. Illustrations of this are abundant, and some excellent ones are given by McBrayer in a report of tuberculosis in a village in North Carolina.

But, granted the occurrence of family tuberculosis, how are we to interpret it? Do the children of those whose resistance to tuberculosis has been inadequate inherit a faulty resistance, or is it merely a matter of excessively large and frequent infection, or do both factors operate? Adams, and King, whom he quotes, feel that far from having a lower resistance, persons with positive family histories have a higher resistance, a greater tendency to recovery and chronicity, than others who contract tuberculosis have. There may be truth in this observation, if only adult victims of phthisis are considered, for the adult tuberculous invalid with a positive family history is often a survivor, many of whose less resistant brothers and sisters have already died of acute tuberculosis in childhood.

Against the hypothesis of special susceptibility inherited from tuberculous parents stand the reports of the Oeuvre Grancher. This institution, which removes the children of the tuberculous from their parents and cares for them in healthful surroundings, reports a very low incidence of tuberculosis among its charges. An identical observation in regard to cattle has been made by Calmette. The low tuberculosis mortality among the native population of Colorado Springs, many of whom are the children of tuberculous parents, has been emphasized by Gardiner, and is evidence to the same effect. For equipoise, we ought to have reports of children from healthy families who have been brought up in close contact with the tuberculous. This often happens, and some cases of resulting disease have been reported, but no large body of data has been collected. We agree with the conventional creed of contemporary phthisiology in believing early exposure to be of the gravest importance, though we believe also that there are very great and significant racial and individual variations in the power to cope with the disease, and that these appear very early in lifea subject which calls for more ample discussion. Raymond Pearl, one of the foremost students of this problem, says: "Familial contact with active open cases is beyond question a factor in determining the incidence rate of clinically active tuberculosis. It appears equally obvious, however, that it certainly does not account for the whole, and probably accounts only for a small part of the increase in the incidence of the disease which we find to occur as the amount of tuberculosis in the immediate direct ancestry increases."