TUBERCULOSIS (Neo-Lat., from Lat. tu berculin'', little swelling. pimple, tubercle, di minutive of tuber, swelling, tumor, knob on plants), or CONSUMPTION. An infectious dis ease, caused by the Bacillus tuberculosis, characterized by the formation, in the tis sues, of nodular bodies, called tubercles, and manifested symptomatically by fever, cough, dyspmea, and progressive loss of strength. The disease is widespread and causes about one-seventh of the deaths throughout the world. Its clinical features were recognized many centuries ago, and Hippocrates and Galen described them very accurately; but it was not until the growth of anatomical study in the 'sev enteenth and eighteenth centuries that the char acteristic lesions (tubercles) were recognized and associated with the disease. Important addi tions to the pathological knowledge of tubercu losis were made by Bayle (1810) and to its physical diagnosis by Laennec (about 1834). Virchow's work in cellular pathology and final ly Koch's brilliant discovery of the causative bacillus in 1S82 settled all doubts as to the genesis and pathology of the disease, and since then nothing essential has been added to our knowledge concerning it.
Consumption prevails in all latitudes. To ward the poles and in very high altitudes the mortality is somewhat lower. No race is ex empt, but negroes and Indians, and other races to whom the disease is comparatively new, are espe cially susceptible. In rare instances the disease is congenital, derived from the mother; there has been found no proof of paternal transmission either in man or animals. The great frequency in young infants of tuberculosis, whether of the lungs, meninges, or bones, is taken by many ob servers to prove that the virus can be trans mitted. Heredity plays an important role in de termining the disease in individuals. Children of tubercular parents are more liable than others to contract consumption, and hereditary pre disposition can often be traced in a family for several generations. Two classes of individuals naturally predisposed toward consumption have long been recognized: the one tall, with straight limbs, regular and even beautiful features, dark hair, long eyelashes, thin and delicate skin; the other stunted, with coarse features, thick lips, light hair, sluggish action, and a tendency to en largement of the lymph glands. A predisposition to tuberculosis is acquired under conditions that seriously lower vital resistance. Among those are overcrowding, deficient ventilation, poor food, prolonged and exhausting disease, preg nancy and lactation, and unhealthful occupa tions, such as glass-blowing, coal-mining, street sweeping, exposure to cold and damp. and the excessive use of alcohol. The disease is most frequently acquired in early adult life (from twenty to thirty-five). The pulmonary compli cations following measles and whooping-cough in children are often forerunners of a tubercu lous deposit in the lungs. The direct medium of contagion is the sputum of the tuberculous pa tient. The number of bacilli thrown off in this manner is enormous. By a patient moderately advanced in the disease Nuttall estimated there were expectorated in the twenty-four hours be tween two and four billions of bacilli. The sputum becomes dry and desiccated, the bacilli are distributed by the dust and obtain entrance to the body again through the respiratory tract. The flesh or milk of tuberculous cattle is capable of transmitting the disease both to man and to other animals. Many cases of intestinal and
mesenteric tuberculosis in children are attribut able to this source. Finally, infection can be brought about by direct inoculation. Demonstra tors of morbid anatomy, butchers, and handlers of hides are subject to a local tuberculosis of the skin. Infection has taken place from circum cision, washing the clothes of phthisical patients, and through a cut from a broken sputum cup.
When the tubercle bacilli have once definitely invaded the bungs the disease runs its course with different degrees of rapidity. It may be fatal in three or four• months, or ten to fifteen years may elapse between infection and death. During this time it may be quiescent for months or a year or more. Two types are usually recognized. The rapid form (galloping consumption) begins after a cold or exposure, with rapidly rising tempera ture, pain in the side, difficult breathing, rust colored sputum, and consolidation of one or more lobes of a lung: in other words, like an attack of pneumonia. Instead, however, of improving at the end of the tenth day, the symptoms become graver, the fever continues high, the lung is rapidly softened and destroyed, and the patient dies in from three weeks to as many months. This form is always fatal. The second type, sometimes called chronic ulcerative phthisis, comes on more slowly and runs a longer course and includes the majority of cases of pulmonary tuberculosis. The disease begins with a slight but annoying and unproductive cough, chilly sen sations, indigestion, loss of appetite, and grad ually increasing weakness. As the trouble pro gresses, the cough becomes severe and constant, with yellow or whitish expectoration. contain ing usually multitudes of bacilli, and sometimes tinged with blood. Fever is higher in the after noon and evening and the temperature rarely drops to normal. Night sweats, pains in the chest, steadily progressing weakness, dyspmea, and wasting are now present. (ccasionally quan tities of blood are brought up (hemoptysis) dur ing a paroxysm of coughing. it is bright red, frothy, and due to the ulceration of an artery of some size. The course is not always fatal; file disease may be arrested at any stage, and partial or complete healing take place, leaving sears or cavities in the lung. Improvement may be only temporary and the process start up again under favorable conditions. In fatal cases the last stage is marked by an exhausting diarrhma, and swell ing of the lower extremities. Death may take place suddenly from hemorrhage or gradually from exhaustion. Examination of the chest shows a deficient expansion of the ribs, rapid heart ac tion, exaggerated voice sounds, irregular and high-pitched respiration, and different varieties of rides, depending on the stage of the morbid proc ess. The prevention of tuberculosis is one of the most difficult problems with which the sanitarian has to grapple, the disease being so widely dis seminated, and so insidious in its approaches. Efforts in this direction are mainly directed to destroying tuberculous cattle, segregation of phthisical individuals. and destruction of their sputum. Municipal ordinances against spitting in public places have been passed in many cities. In sanatoria patients use special receptacles for their sputum, which is thoroughly disinfected and burned. Boards of health in the larger cities are taking note of cases in private life and urging them to dispose of expectorated matters in a sanitary way.