TUBERCULOSIS: ITS CAUSATION AND PREVENTION. By HERMANN M. BIGGS, M.D., Medical Officer and Director of the Bacteriological Laboratories, No subject more vitally concerns the welfare of a community than that pertaining to its healthfulness. How its members live, and how and at what age they die, how much sickness occurs among them and what is its nature, are questions of vital importance, both to the community as a whole and to each individual in it. These are essential features of the problem, whose gradual solution will teach men more and more how to live properly, and how they may secure longer, healthier, and therefore happier lives. The healthfulness of any community or locality is to be judged by the statistics of sickness and death, considered in relation to the causes of such sickness and death (it is not only the number of deaths or the number of cases of sickness in proportion to the population, but also the nature of the diseases which cause this). In rural districts the degree of healthfulness depends largely on the natural conditions, such as elevation, climate, soil, and to a less extent upon artificial conditions. In densely populated cities, on the contrary, the natural conditions become relatively unimportant factors in determining the degree of healthfulness, so much do they become subordinated to the artificial conditions resulting from the lives and labor of the inhabitants. It may be said, within certain limitations, that the inhabitants of every city have it largely within their power to determine what the death rate of their city shall be. The presence of much sickness and of a high death rate in any urban population are largely due to the existence of unsanitary conditions in the occupations, habitations, food and water supply of the inhabitants-all factors which lie to a great extent within their control. Hence, when any city has a high death rate -for example, when thirty or thirty-five persons out of every thousand of the population die each year, as was formerly the case in Liverpool and New York, instead of fifteen or twenty, as is the case in many of the larger cities to-day-it is because unsanitary conditions are permitted to exist. These exist to a very small extent, from necessity, but chiefly because of ignorance, neglect and indifference on the part of the people, or incompetence on the part of the authorities. The average length of life in any country or city is spoken of as the "expectation of life at birth." This average life term in some cities for instance in Liverpool and Manchester, which have been distinguished for their high death rates-is often but little more than one-half that of the healthiest country district. The average lifetime of each person born in Liverpool, until recently, was twenty-six years; in London it was thirty-seven years; while in Surrey, a healthy district, it was forty-six years. These considerations show how vast is the significance to every individual of the degree of healthfulness of the community, for upon it depends not only his or her relative freedom from illness, but also his or her probable lifetime. In the casual consideration of the healthfulness of communities as compared with the conditions existing in earlier centuries, we are inclined to think, without investigation, that there has been but little advance in modern times, and that while some diseases have been greatly restricted, or entirely stamped out, these have been replaced by others equally as fatal to the human race. More careful study, however, shows how erroneous are these views. In the seventeenth and eighteenth centuries, the average annual death rate per 1,000 of the population throughout the civilized world was at least 50, and probably much more. From 1620 to 1643, the absolute annual mortality for London was over 70 per 1,000 of the population, and the average duration of life of each person born, less than fifteen years. One hundred and fifty years later, for the decennial period ending in 1780, the expectation of life (or the average lifetime) in London had increased only four years, and was nineteen years; while from 1831 to 1835, including an epidemic year, the death rate had fallen to 32 per 1,000, and the mean expectation of life had increased from nineteen years to nearly thirty years. At the present time the mean life term for all England is considerably more than forty years, or more than double that of 1780. From 1770 to 1780, in London, not less than 5 in 1,000 died annually of smallpox; the death rate from this disease is now an insignificant fraction. In the sixteenth century, fever, plague, cholera and dysentery-diseases which are now practically extinct in civilized communities-destroyed annually nearly 31 out of every 1,000 of the inhabitants of London, or nearly twice the total deaths now from all causes. Even previous to 1875, 518 out of every 1,000 children born in Liverpool died during the first ten years of life, while in the healthy districts of England only 205 died during this period. Formerly in New York City more than 600 out of every 1,000 children died during the first ten years of life; this mortality has now been reduced onehalf. I have referred to these general facts in regard to the significance of death rates, and to certain features in the sanitary history of the past, simply to emphasize the importance to the individual of the sanitary conditions of the locality in which he lives, and to bring out more clearly the enormous advances that have taken place in the last fifty years in general sanitary conditions. A large number of those diseases, which in the past frequently decimated the population, have been either restricted within narrow limits, or completely stamped out. Plague, typhus fever, epidemic dysentery, Asiatic cholera, leprosy and smallpox, are among the diseases which either have been completely stamped out in civilized communities, or occur only spasmodically or in small epidemics; their influence in the production of sickness and death has fallen to insignificant proportions. The prevalence of typhoid fever in most well-regulated communities has very greatly decreased. Through the introduction of diphtheria antitoxin, the mortality from diphtheria has been reduced to one-half, onethird, or to even one-fourth in some localities, of what it formerly was. Through the remarkable observations made in Cuba by Ross, of the United States Army, and his associates, the prevalence of yellow fever is likely to be restricted, in the future, within narrow limits, as has been previously the case with each of the other great epidemic diseases. I might mention several other infectious diseases whose prevalence has been restricted within very much narrower lines through the developments in modern preventive medicine, and among these is tuberculosis; and still there is no problem which confronts the sanitary authorities of the large municipalities at the present time equal in its importance and magnitude, than that presented by the tuberculous diseases, nor is there any other sanitary proposal which offers the promise of such vast returns in a diminishing rate of sickness and death, as one which provides successful measures for the prevention of this disease. This, although not a new problem, is of supreme importance. The tuberculous diseases are not more prevalent than formerly; on the contrary, there has been a steady and material decline in the death rate caused by them in most of the large cities of the world; but only in recent years have the sanitary authorities and the medical profession begun to have some realization of the great possibilities in the restriction of this disease. A comprehension of the full significance of the discoveries of Robert Koch, made twenty years ago, on the prevention of tuberculosis, has only slowly found its way into the minds of the medical profession, and even now a large proportion of the profession and of the laity have failed to grasp its vast influence on the present and future happiness and prosperity of the human race. Koch showed in 1882 that tuberculosis was an infectious and communicable disease, produced by a germ, the tubercle bacillus. It followed, as a necessary result from his discoveries, that it was an absolutely preventable disease. So slowly, however, did the significance of these discoveries penetrate the minds of the profession and the people that already twenty years have passed, and we have only just now begun to organize inadequate measures for the prevention of this disease. Statistics, showing the great prevalence of the tubercular diseases, have been quoted so frequently as to have almost lost their force, and still the people, the legislators, the sanitary authorities, and even the medical profession, have remained indifferent to the vast expenditure unnecessarily made by the human race to this evil. Only limited, ineffectual efforts are made in its suppression, and we still view with comparative indifference the ravages of a disease which causes from one-quarter to one-third of all the suffering and death at the best period of life-between the ages of fifteen and fifty-five; and this, too, when the evidence at command should be, it seems to me, conclusive to every reasonable mind that this loss could be largely prevented at a comparatively small cost in sacrifice, labor and money. I make this statement with a full realization of its meaning, and after a familiarity with the sanitary problems involved gained by an active participation in their study in a great city for a period of nearly fifteen years. It may be useful to discuss, in as simple a manner as possible, certain questions which are suggested in regard to tuberculosis. First: What is tuberculosis? The disease known as tuberculosis, and when affecting the lungs, as pulmonary tuberculosis or consumption, is an infectious and communicable disease. It is very common in human beings and in certain of the domestic animals, especially cattle. About one-fourth of all deaths occurring in human beings during adult life in all civilized countries is caused by it, and nearly one-half of the entire adult population at some time in life acquire it. It has been proven beyond any possibility of doubt, that a living germ, called the tubercle bacillus, is the cause, and the only cause, of tuberculosis. It does not seem neces sary to state the facts upon which this assertion is based, for the discovery, first made by Robert Koch in 1882, has been confirmed so often and so completely, that it now constitutes one of the most absolutely demonstrated facts in medicine. Tuberculosis may affect any organ of the body, but most frequently first involves the lungs, and is then commonly known as consumption. When it affects the skin it is known as lupus; the lymph glands are frequently diseased, and especially those in the neck, and this type was formerly known as scrofula. The commoner forms of chronic disease of the knee joint, hip joint, and spine are generally the result of tubercular infection of the joints and bones. The disease may also affect the throat, the intestinal canal, the coverings of the brain, or any of the other organs and tissues of the body. It is always the same disease when found in any one of these parts, and always produced by the same germ-the tubercle bacillus. When these germs find their way into the body they multiply there, if favorable conditions for their growth exist, and produce small new growths or nodules, which are called tubercles, and from these the disease tuberculosis derives its name. result of the action of the germs contained in the tubercles they tend to soften, and the discharge from these softened tubercles containing the living germs-tubercle bacilli-are thrown off from the body. In pulmonary tuberculosis, or consumption, these germs are contained in the expectoration, often in most incredible numbers. It has been estimated that in some cases two or three thousand million tubercle bacilli are discharged in the expectoration from a single case of consumption in the course of twentyfour hours. The germs thus thrown off do not grow under ordinary conditions outside the living human or animal body, although they may frequently retain their vitality and virulence for long periods of time, even when thoroughly dried. As tuberculosis only results from the action of these germs, it follows, from what has just been said, that when the disease is acquired it must result from receiving into the body the living germs which have come from some other living being affected with the disease. As the |