Tuberculosis : The New Challenge to the 436

A a profession, we in medicine find ourselves in exciting times. Breakthroughs in the scientific basis of our knowledge continue to expand in a wealth of literature and journals. As the “art” of medicine becomes more scientific, more measureable, the practicing clinician finds himself buffeted by peer reviews, utilization committees, relicensure movements, hospital admission review programs, and spiraling malpractice suits and costs. It is little wonder that a major change in the medical care delivery system within the United States has gone almost unnoticed by organized medicine and the individual clinician. In fact, we are witnessing the near completion of an entire circle, the culmination of four distinct eras in the treatment of a major disease. For generations, man, the tubercie bacillus, and the practicing clinician were all intermeshed. Society accepted tubercu!osis as its inevitable companion. During the nineteenth century, it was still commonly believed that everyone had a “touch of TB.” The etiology of the disease was variously attributed to heredity, unhealthy climate, miscarriages, measles ( in children ) , over-lactation, “pre-disposition,” impure air, improper food, typhoid fever, scarlatina, masturbation, mental depression and damp, wet soil. When the bright light of science finally focused on the tubercle bacillus in 1882, the relationship of the disease, the patient and his physician began to change dramatically. A new era began, an era of enthusiasm-and hope -perhaps best personified by the great Dr. Trudeau. The separation of tuberculosis from the mainstream of medicine had begun. The next generation saw a massive nationwide commitment to the development of institutions specifically designed for the care of tuberculosis-the sanitoriums-beginning with 12,000 beds in 1908 and culminating in over 97,000 beds in 1942.’ The tuberculosis specialist, the phthisiologist, was now responsible for the complete physical and mental care of the patient. Total control of the patient’s life and environment was standard treatment, and the separation of tuberculosis care from the practicing clinician became commonplace. The early ‘40’s ushered in a third era-an era in which progressively refined diagnostic tools and man’s imagination combined to achieve major breakthroughs in our understanding of the epidemiology and pathogenesis of tuberculosis. Application of both this knowledge and new techniques in areas such as casefinding surveys solidified the role of public agencies in tuberculosis control. Finally, with the advent of streptomycin, PAS and isoniazid, the early 1950’s witnessed a therapeutic revolution which cast aside pneumothorax, pneumoperitoneum, surgical intervention and even that old mainstay-rest therapy. This was an era that most practicing clinicians were certainly aware of, but in which they were rarely involved. During these four eras, our knowledge of the relationship between the tubercie bacillus and man has advanced significantly. We have learned that the infectious unit of tuberculosis can be a single tubercle bacillus usually carried on, or as an airborne “droplet nucleus” produced by a person with pu’monary tuberculosis. Such particles may be small enough ( 1 to 10 g) to be kept airborne by air currents normally present in any room. Thus, once produced, these particles may disperse easily throughout the room.4’5 On the other hand, larger particles fall to the floor or, if inhaled, are quickly captured in the mucous defenses of the upper airway, moved out of the airways by the mucociliary flow, and probably meet an untimely end during their passage through the gastrointestinal tract. Unfortunately for man, the smaller “droplet nuclei” are able to avoid this mucous fate and are carried by the flow of air past the respiratory defenses into the recesses of the alveoli. Once lodged comfortably within this source of nutrients, the bacillus begins to multiply. In a body with prior immunologic experience with M tuberculosis, host defenses are quickly mustered to contain the new invader, but in the previously uninfected individual, the scenario is different. Apparently, because they elaborate no toxins,