Tuberculosis and acquired immunodeficiency syndrome: a historical perspective on recent developments.

The incidence of tuberculosis has increased in recent years, at least in part as a result of the ongoing worldwide epidemic of acquired immunodeficiency syndrome (AIDS). In addition, the occurrence of outbreaks caused by multidrug-resistant Mycobacterium tuberculosis organisms has greatly heightened concern. In retrospect, a number of seminal studies that have appeared during the past decade have helped to define changing concepts concerning the epidemiology, pathogenesis, approaches to preventive care, diagnosis, and treatment of tuberculosis in HIV-infected persons. Such reports have shown that the variable clinical manifestations of tuberculosis in patients with AIDS are greatly influenced by the degree of HIV-induced immunosuppression. Explosive outbreaks of tuberculosis occurring in closed environments have emphasized that patients with AIDS and pulmonary tuberculosis may be highly contagious, especially when diagnosis and implementation of appropriate infection control measures are delayed. The extent to which homelessness and illicit drug use complicate management of tuberculosis have been examined, and the high risk of persons who are both tuberculin-positive and HIV-positive ultimately developing active tuberculosis, unless chemoprophylaxis is completed, has been clearly shown. The utility of sputum smears, bronchoscopy, and newer technologies such as polymerase chain reaction for diagnosis has been examined. The risk of relapse appears to be low when patients with AIDS with drug-sensitive tuberculosis complete appropriate multiple-drug therapy. Recent reports have addressed important hospital infection control, tuberculin testing, and chemoprophylaxis issues. This paper describes this evolution of understanding, focusing on reports that we believe have been conceptually important.