Tuberculosis (TB) is caused by a bacterium called Mycobacterium tuberculosis. The bacteria usually attack the lungs, but TB bacteria can attack any part of the body such as the kidney, spine, and brain. Not everyone infected with TB bacteria becomes sick. As a result, two TB-related conditions exist: latent TB infection (LTBI) and TB disease. If not treated properly, TB disease can be fatal.
How TB Spreads
TB is spread through the air when a person with active TB disease coughs or sneezes. People nearby can breathe in these bacteria and become infected. People with the highest risk are those who have prolonged or frequent contact with an infected individual, such as family members, friends or coworkers.
Someone with latent TB infection (LTBI) cannot spread it to others.