Tuberculosis (TB) is caused by the bacterial group known as Mycobacterium tuberculosis complex (eg., M. tuberculosis, M. bovis, M. africanum, M. microti, M. canetti, M. pinnipedii, M. mungi, M. caprae). Mycobacterium tuberculosis is the most common of this complex to cause TB disease in humans, while the other members of the complex cause disease similar to TB. These bacteria may be transmitted from person to person through the air. Coughing or sneezing by individuals infected with active TB disease causes the release of microscopic droplets (containing tubercle bacilli) into the air. These droplets may then be inhaled by others. TB usually affects the lungs, but can also cause infection in the brain, spine, kidneys, and other locations. In pulmonary TB, the tubercle bacilli multiply in the alveoli of the lung.
3. CDC/ V. McPheeters. This photomicrograph of a Ziehl-Neelsen-stained specimen revealed the presence of magenta stained, rod-shaped, acid-fast, Mycobacterium tuberculosis bacilli. PHIL. Creation Date: 1965. Copyright Restrictions: None - This image is in the public domain. Accessed March 5, 2022. https://phil.cdc.gov/Details.aspx?pid=23000
