Tuberculosis is caused by a group of organisms: Mycobacterium tuberculosis, M bovis, M africanum and a few other rarer subtypes. Tuberculosis usually appears as a lung (pulmonary) infection. However, it may infect other organs in the body. Recently, antibiotic-resistant strains of tuberculosis have appeared. With increasing numbers of immunocompromised individuals with AIDS, and homeless people without medical care, tuberculosis is seen more frequently today. (Image courtesy of the Centers for Disease Control and Prevention.)
Review Date 11/14/2016
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital, Boston, MA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.