MYCOBACTERIAL INFECTIONS AND HIV

Mycobacterial infections are a frequent complication of human immunodeficiency virus (HIV) disease. The incidence of tuberculosis has increased dramatically in developing countries and the United States as a result of the HIV epidemic. Recently, it has been learned that HIV infection accelerates the natural history of new Mycobacterium tuberculosis infection, resulting in a high incidence of early tuberculosis disease. Nosocomial outbreaks of drug-sensitive and drug-resistant tuberculosis in HIV-infected persons have been reported in a number of cities. The emergence of multidrug-resistant tuberculosis has been promoted by inadequate efforts to provide complete therapy to tuberculosis patients. Multidrug-resistant tuberculosis responds poorly to treatment and has a high mortality rate in HIV-infected individuals. Chemoprophylaxis of tuberculosis in people with HIV infection is complicated by reduced sensitivity to tuberculin skin tests. Disseminated Mycobacterium avium-complex infections occur in a large proportion of HIV-infected persons with low CD4 counts. In advanced HIV infection, the incidence of M. avium-complex bacteremia is reduced significantly by chemoprophylaxis with rifabutin. Treatment of disseminated M. avium-complex infection with the new macrolides clarithromycin and azithromycin is highly effective, though in vitro resistance develops when these drugs are used alone. Combination therapy with a macrolide and another agent is necessary.