Tuberculosis in patients with human immunodeficiency virus infection

Tuberculosis (TB) is the major opportunistic infection of human immunodeficiency virus (HIV)-infected persons worldwide. Human immunodeficiency virus infection is the most potent known risk factor for reactivation of latent Mycobacterium tuberculosis infection, and TB disease appears to increase the rate of HIV progression. Pulmonary disease is seen in most patients, including a large proportion of those with extrapulmonary disease. Failure to suspect TB and to order the appropriate diagnostic tests is the most common reason for diagnostic delays. With advancing HIV infection, tuberculin skin test reactivity decreases along with reactivity to nonspecific antigens such as mumps, tetanus toxoid, and Candida; anergy testing need not be a routine component of tuberculosis screening of HIV-infected persons. The diagnosis depends on identifying the organism on smears or cultures; direct amplification tests may facilitate rapid identification of M. tuberculosis, but the relatively low sensitivity in smear-negative specimens limits their use. Also, these tests must be used in conjunction with the clinical assessment, and they must always be performed in conjunction with microscopy and standard culture. Shorter courses of combination preventive therapy of patients with latent tuberculous infection are effective, but the potential advantages of improved adherence and reduced costs of shorter courses should be balanced with an increased risk secondary to ongoing TB exposure in areas with a high TB prevalence. Six months of treatment for active tuberculosis is recommended, unless the response of a particular patient is slow or otherwise suboptimal. The use of highly active antiretroviral therapy (HAART) made a remarkable impact on the course or HIV disease, but raises several issues with respect to HIV-related TB. Drug interactions necessitate either a non-rifamycin-based regimen or a rifabutin-based regimen in patients on HAART treated for TB.