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THE EXTINCTION OF TUBERCULOSIS.
For over two thousand years a portion of the medical profession has believed in the contagiousness of consumption. A not inconsiderable proportion of the laity has likewise leaned to this view. So strong was this belief at one time that toward the close of the eighteenth century a law was promulgated in the kingdom of Naples, making very stringent regulations looking to the registration of consumptives, the segregation of the sick in hospitals and the destruction of infected articles. It seems that at the beginning of the present century the prevalence of consumption in Southern Italy was so great that the expression "see Naples and die" could almost be taken in its literal sense.
About thirty years ago Villemin demonstrated the communicability of tuberculosis by a series of experimental inoculations upon animals. The results obtained by this investigator were soon confirmed by Chauveau and others. It was, however, not until the epoch-making discovery of the tubercle bacillus by Robert Koch in 1882, that the value of the researches of the two distinguished French experimenters was generally recognized. Since that time the view that tuberculosis is an infectious and communicable disease has gradually pervaded the profession until to-day there are probably few physicians, laying claim to common sense and current knowledge, who would attempt to controvert it.
Coincidently with the general acceptance of the infectious nature of tuberculosis have come experiments to more definitely indicate the common methods of infection, and endeavors to restrict the disease within narrower limits. That this is a laudable striving must be conceded when we reflect that the annual mortality from tuberculosis in its various forms in the United States is 163,500, or nearly 450 per day; and that in this city the deaths from consumption of the lungs alone reach nearly twelve hundred per year, a ratio of 13.69 per cent. to the total mortality. If the deaths from tuberculosis in its various forms were included, the ratio would mount to over 14 per cent, or 1 in 7, which is the
ratio throughout the world, as stated by Koch in his memorable paper announcing the discovery of the Bacillus Tuberculosis.
In accepting the infectious nature of this disease, we must not overlook the influence of the receptive condition of the individual in determining the time or place of infection. While the value of hereditary predisposition in determining phthisis is often over-estimated, we cannot ignore it altogether; neither may we undervalue the effect of an acute or chronic inflammation, a traumatism, or other weakening factor in rendering the tissues less resistent, or more receptive to the infective agent. These and many other conditions governing the infection of the individual must be recognized and accorded their full worth. The essential fact remains however that without the inoculation of the bacillus tuberculosis we cannot have consumption, or any form of tubercular disease; and if by any means we can exclude this infective agent from the body the individual is safe from the disease.
There are two principal channels of infection in tuberculosis; one is by the digestive tract and the other, far the more important, by the respiratory organs.
Children are especially liable to infection by way of the digestive organs. An infant nursed by a consumptive mother, or one fed on milk from tuberculous cows may become tuberculous if the food contains the infective agent. It has been shown that the milk may contain tubercle bacilli, even though there is no recognizable local tubercular disease of the lacteal glands. It is highly probable that the frequency of tuberculosis of the intestinal canal, the peritoneum, the mesenteric glands and other abdominal organs in the young, is in most cases attributable to direct infection by tuberculous milk. In the adult this avenue of infection is likewise open. Meat from tuberculous animals, or other articles of food accidentally contaminated by the tubercle bacillus may be the medium of communication. Secondary infection, from swallowing the bacillus-laden sputum from the lungs is also not infrequent.
I need hardly say, however, that in the great majority of cases of tuberculosis the infection takes place by way of the respiratory organs, which also become the principal and generally the only seat of the disease.
It is held by some, and I am inclined to consider the belief well founded, that the tubercle bacillus cannot effect a lodgment in the tissues and begin its destructive action, unless these are weakened in their resistive power by an inherited defective organization or by acquired conditions of lowered vitality. It is a result of clinical observation that a catarrhal pneumonia, for example, is often a forerunner of pulmonary consumption. It is assumed, with good reason, that the anatomical elements of the lining membranes of the inflamed air-cells and finer bronchial tubes succumb to the attacks of the invading germ, carried in the inspired air, while in a state of health the tissues could resist the destroying organism. This simply emphasizes the importance of avoiding any factors tending to depress the vital condition of the organism or any of its parts.
The tubercle bacillus does not multiply under ordinary conditions outside of the body, and the fully developed organism when removed from the conditions favoring its growth in the body soon loses its vitality. But the spores of the bacillus, or the germs of the germ, as one may say, are extremely resistant and retain their power of growth and development for a considerable period. The dried spores are thus always potential sources of mischief if accidentally taken into the system by inhalation or swallowing. They may also be inoculated in wounds or traumatisms, but this mode of infection is comparatively rare, and may be left out of account in the present discussion.
Careful investigations by Baer and Cornet have shown that the death rate from consumption is four times as great in German prisons as among the free population of the same age. In convents, asylums, and similar institutions, tubercular diseases are also extremely prevalent. In the Maryland Hospital for the Insane over thirty per cent. of the
deaths are due to tuberculosis. I am confident that within the last two years, at least three patients contracted the disease by infection in the wards. Efforts have been made recently to minimize this danger.
Dr. Lawrence F. Flick has shown by a patient and laborious study of the causes of death in the fifth ward in the City of Philadelphia that certain houses in that ward are infected. He found that for a period of twenty-five years, from 1863 to 1887, all the deaths from tuberculosis in the ward occurred in less than one-third of the houses, while in 1888 over onehalf of the tubercular deaths occurred in these same houses, demonstrating beyond a doubt that these houses were infected.
I can hardly think it necessary to adduce proof that the tubercle bacillus is in all cases of tuberculosis the active agent of the infection. Recent investigations, especially those of Cornet, have shown the manner in which infection occurs. The breath of consumptives contains no bacilli and is not infective. Even when the lungs are full of broken down tissue swarming with bacilli, the latter are only in the rarest instances, if at all, exhaled in the breath. Of course, during a fit of coughing, small particles of pus and secretion containing bacilli may be carried along in the forcible expulsion of air from the lungs, but even this is probably rare. Ordinarily the air of rooms or of hospital wards occupied by consumptives is free from bacilli and may be breathed with impunity. It is only when the dust of the room, containing dried and pulverized sputa, is disturbed by sweeping, or shaking up the bed-clothing, or in other ways that danger of infection occurs. Scrapings from the walls of rooms occupied by consumptives, inoculated into animals produced tuberculosis in twenty per cent. of the latter. Control experiments showed that dust from the walls of houses, hospital wards and public buildings not inhabited by tuberculous patients was not infective. Cornet showed also that the dust from the walls was in no case infectious when sputum cups were used to receive all expectorated matter, although
such expectoration was full of bacilli. Praussnitz has demonstrated the presence of tubercle bacilli in the scrapings from the interior of railway carriages on one of the German railway lines carrying many consumptive passengers. Thus is experimentally demonstrated a danger to which attention had previously been forcibly drawn by Whittaker, Gihon and others.
It is generally agreed among physicians that if the stools from a case of typhoid fever are disinfected before being thrown out where they may contaminate the drinking water supply, there is little if any danger from further infection. The alvine excreta being recognized as containing the infective agent, the destruction of the latter renders the material innocuous. In like manner it may be accepted as demonstrated by recent researches that if the sputa of a case of consumption be disinfected as soon as expectorated the consumptive patient is no longer a source of danger to his neighbor.
From the foregoing it becomes evident that the principal measures of prophylaxis against tuberculosis must be such as comprise; first, immediate destruction of the bacillus tuberculosis in the sputa, or in other excretions when the case is not a pulmonary one; second, the disinfection of clothing and bedding, or other furniture liable to be contaminated with the infective material. As accessory measures must be considered, notification to the health authorities of all cases of consumption, public disinfection of infected houses. and conveyances (ships, railway cars) and the establishment of special hospitals for the free treatment of indigent consumptives.
The first example of an attempt at a thorough-going restriction of tuberculosis is the decree of the King of Naples in 1782, before referred to. According to De Renzi, quoted by Flick, this decree contained the following propositions:
"I. The physician shall report the consumptive patient, when ulceration of the lungs has been established, under