Vol. XXXVII.

"Keep the Home Fires Burning"

No. 12

Original Contributions

[EXCLUSIVELY FOR THE MEDICAL HERALD.]

HE PRESENT STATUS OF THE TUBERCULOSIS PROBLEM*

FRANCIS M. POTTENGER, A. M., M. D., L. L. D., Monrovia, Cal.

The past quarter of a century has witnessed e almost complete revolutionizing of medical cience. The development of clinical medicine as gone for the most part hand in hand with he development of the laboratory. This has not een due to the fact that all possible progress utside of the laboratory has been made, but ather to the fact that the immediate past has jeen so preeminently an age in which laboratory esearch has predominated, that clinical medicine as been more or less content to apply laboratory acts to clinical disease instead of making the painstaking study of the patient that it should.

By this intensive specialization our knowledge of the various diseases and the pathological

Read by invitation before the thirty-first annual meeting of the Medical Society of the Missouri Valley, Omaha, Neb., September 19-20, 1918.

processes which they produce, has been greatly extended. The causative microorganism and the method of its transmission has now been proven for most of our common infections. Resulting from this research, many diseases which formerly seemed inevitable are now prevented and likewise many which were considered incurable are now successfully treated.

Of the many diseases which have been the recipients of intensive study during this period, none has received more attention than tuberculosis. While we must acknowledge disappointment in not yet being able to announce simple methods for its prevention and a positive specific remedy for its cure, yet we are able to report that very important progress has been made. The knowledge so far gained, if properly applied, will exert a gratifying influence both upon the morbidity and mortality of this world-wide scourge.

As a result of the intensive study of tuberculosis during the past few years, many important facts have been established which may be interpreted with varying degrees of optimism. The viability of the bacillus outside of its host; the general prevalence of the disease, both as an infection and as a clinical entity; its chronicity, particularly after reaching the open stage; and the fact that it may be transmitted through milk,

one of the most important articles of diet; make the prevention of infection, for the present, a very difficult matter. These facts emphasize the necessity of controlling the morbidity as well as mortality: first, by preventing tuberculous in fection from becoming clinical tuberculosis; and, second, by curing as large a number as possible of those who are suffering from the clinical dis

ease.

This presupposes a diagnosis of clinical tuberculosis as early as it can be made, and the immediate intelligent application of those measures which are helpful. To this end the patient who has the disease must be as carefully studied as the disease which has the patient. While hoping for the laboratory to give us a remedy of similar specific action to antitoxin in diphtheria, quinine in malaria, and arsenic and mercury in syphilis, we must not remain idle. We can probably make most advancement during this time by carefully studying the patient and learning how the disease affects him and how these influences may be avoided or counteracted.

My work as a clinician has particularly led me into the study of the patient, although I have not neglected the study of the disease in its varied aspects. I was early convinced that better methods of diagnosis and more successful results in therapy were necessary if tuberculosis was to be coped with; and now, after several years of close observation and study, I believe I am able to show a certain amount of definite progress which points the way to a better understanding of the patient who has tuberculosis, and offers an explanation of the manner in which the disease affects him. Clinical tuberculosis which appears to be such a complex disease may be analyzed in such a manner as to satisfactorily explain nearly all of its many and varied symptoms. This knowledge facilitates diagnosis. It helps us to appreciate the early signs of activity and to differentiate between activity and quiescence in borderline cases. It further is of aid in applying a rational therapy. Before entering upon this interesting and important discussion I wish to recall some of the more important phases of the subject which have been studied during the past few years, and to place before you what I believe to be the best teaching at the present time; remembering that until the subject is thoroughly understood, all supposed facts are subject to change.

Phthisiogenesis

One of the most important and far-reaching acquisitions to our knowledge of tuberculosis is that with reference to the subject of phthisiogenesis. We had at the beginning of our intensive study of the subject, classed tuberculosis. among the chronic infections; but, in the over

throw of the theory of heredity, and the enthronement, in its stead, of the idea of postnatal infection, we emphasized the danger of contact to such an extent that it was assumed that the danger in associating with those ill of tubercu losis was great and universal. In the minds of those who were least conversant with the nature of the disease, even a casual association with one open case was considered sufficient for infection to occur. This idea was the parent of an unjust and unwarranted phthisiophobia which caused all kinds of injustices to be do to the tuberculous patient. We now believe that there is no danger in casual contact, and that the only time when considerable infection occurs is it childhood.

Pathologists had known for many year that the glands of children, particularly thom who lived under bad conditions, were frequen infected with tuberculosis. It was not until the discovery of the cutaneous and ophthalmic to berculin tests, however, that we really had an definite idea of the universality of tuberculosi infection in early childhood. These tests applies to large groups of children in many differe countries, revealed the surprising fact that the body cells of from 50 to 100 per cent of childre were sensitized to the tubercle virus before they were fifteen years of age; in other words, from 50 to 100 per cent of the children tested, varyin according to the groups, had already been fected with the tubercle bacillus.

We now were able for the first time to unde stand tuberculosis. It is a disease which gai access to the body during childhood, but whi may remain quiescent for years and then ber active and produce clinical tuberculosis. were aided in this understanding by the fac which were being coincidentally discovered the field of serology and immunity. We the learned that an infection is followed by an i creased resistance or relative immunity. Th was made evident by studying groups of tube culous patients. While nearly all children infected, comparatively few become clinica tuberculosis during their early years. Those w do during the first year or two of life, nearly die of acute forms of the disease. By the tim the age of six or seven years is reached, resistan begins to be evident and there is a tendency the disease to become chronic; and after the a of fifteen years, tuberculosis shows itself pa ticularly as a chronic infection. It becomes chronic in the later decades than in the earlie ones, which demonstrates that resistance devel with association with the bacillus.

It is now the concensus of opinion that t clinical tuberculosis which is found so often af the fifteenth year of life is produced by b whose antecedents entered the body of the dividual during its early years, and that

their antecedents have lived in the tissues and been able to multiply and produce the active disease. It is further believed that, other condions being equal, the more massive the infection he greater the danger of the individual developng clinical disease. This emphasizes the importance of keeping children from associating intimately with those afflicted with open tubercuosis or from drinking milk from tuberculous cattle.

Source of Infection

It is now believed that the principal source f infection is some human being who has open uberculosis, although cattle as a source of daner is well established. It is generally believed hat 10 or 12 per cent of tuberculosis in children 5 due to the bovine bacillus, having been transitted through milk. I would suggest, however, hat the amount might be much greater for these gures are based on the percentage of lesions 1 which bovine bacilli are found, and do not take to consideration the possibility of bovine balli changing to human bacilli after years of rowth in human tissues. It seems to me most robable that bovine bacilli, growing on human il for a long period of time (years) might ange their morphology and characteristics of rowth, and become undistinguishable from the man bacilli, the same as they change when rown on different media in the laboratory. The esumption of danger from the bovine bacillus so strong that there can be no rational excuse r not using every means for the eradication of berculosis from our dairy herds, and for not

irizing all milk from cows which have not ccessfully passed the tuberculin test. Nevereless, we still recognize that the greatest danlies in human beings suffering from open berculosis.

Diagnosis

My remarks on diagnosis, prognosis and erapy, shall be confined to pulmonary tuberosis. The advances made in the diagnosis of berculosis in recent years has been due: 1, to è fact that a larger group of men have been ing their attention to the disease and so have come more proficient in making examinations mselves and have stimulated others to greater erest; 2, to a better understanding of the nae of the disease through the recent studies in hisiogenesis; 3, to the x-ray; 4, to the tuberin tests; and 5, to a study of the manner in ich tuberculosis affects the patient through visceral nerves.

3. The x-ray. The status of the x-ray is still a matter of discussion. Unwarranted confidence is often put in it; and I have personally seen many worthless plates, the interpretation of which was permitted to seal the patients' fates. The x-ray should not be depended on alone. It should be interpreted in conjunction with a carefully taken clinical history and a good physical examination.

The x-ray has been of great aid in studying. hilus infections, this portion of the lungs being extremely hard to examine by means of percussion and auscultation. A negative opinion based on an x-ray examination should never be acand positive physical examinations. A diagnosis cepted in the face of a positive symptomatology should not depend on any one examining procedure. It should be arrived at by a process of reasoning.

4. Tuberculin Tests. The tuberculin tests, like the x-ray, have exerted a beneficial influence upon diagnosis. They have caused physical examinations to be made with greater care and have shown that the diagnosis can be made earlier than was formerly believed. The value of the tuberculin test depends on the principle developed in immunological studies, that active infection creates active resistance on the part of the body cells. While the evidence of resistance as shown in the sensitiveness of the body cells persists in tuberculosis after the infection becomes quiescent, yet my experience in that class of cases in which the test should be of great value-early clinical cases before destruction of tissue has taken place-confirms the above stated immunological pinciple and warrants the assertion that any cutaneous reaction to any of the tuberculin preparations which comes on promptly, and reaches a maximum of 3/4 to 1 c.m. within the first twenty-four hours, should be interpreted as meaning that that patient at that time, or in the recent past, was suffering from an active tuberculous lesion.

One reason why these tests are not more valuable is because of the variability of the tuberin used. They differ in their antigen content. This can best be overcome by employing several different preparations for each test.

5. The Manner in which Tuberculosis Affects the Patient Through the Visceral Nerves. The original studies which I have made along this line have led to the discovery of important facts which are just beginning to be appreciated. Through them I have been able to explain, classify and evaluate well known symptoms and physical signs; to suggest several new diagnostic signs; and to point out sources of error in the old established methods of examination, particularly percussion. These studies, therefore. make diagnosis easier and more accurate.