Tuberculosis

Abstract

Tuberculosis (TB) is a bacterial disease caused by Mycobacterium tuberculosis, a relatively slow-growing, aerobic, acid-fast bacillus (AFB). Classically, TB is a pulmonary disease, but disseminated and extrapulmonary manifestations may also occur, especially in immunocompromised persons. TB is transmitted person to person and is usually contracted by inhalation of M. tuberculosis droplet nuclei generated by an infectious person. If infection occurs after M. tuberculosis enters the body, the host’s cell-mediated immunity may contain the organism but not eradicate all the bacilli, resulting in latent tuberculosis infection (LTBI). M. tuberculosis can remain dormant and persist (e.g., within macrophages); persons with LTBI are at risk for reactivation and development of active TB. This review contains 5 figures, 7 tables, and 75 references. Key Words: tuberculosis, pulmonary tuberculosis, extrapulmonary tuberculosis, tuberculosis in hiv-infected patients