Changes

==Natural History==

[[Image:Acid-fastbacilli.jpg|200px|right|thumb|Photomicrograph of TB bacilli]]

Tuberculosis can affect any organ in the body, but the primary disease is in the lungs. TB is spread by prolonged contact with someone with active pulmonary TB. This most often occurs in household contacts, or in people who work with an infected person in a workplace with poor ventilation.