Evaluation of exposure to tuberculosis among employees at a medical center.

Tuberculosis (TB), a disease caused by the bacteria Mycobacterium tuberculosis (M. tuberculosis), is spread from person to person through the air. TB usually infects the lungs, but it can also infect other body parts such as the brain, kidneys, or spine. People who are infected by the bacteria but who do not exhibit symptoms have latent TB infection. It is estimated that one-third of the world’s population has latent TB infection, and approximately 5%–10% of those infected will develop TB disease within their lifetimes.(1–5)