what causes tb a virus or bacteria
Causes of tuberculosis. Tuberculosis (TB) is caused by a type of bacterium called Mycobacterium tuberculosis. The condition is spread when a person with an active TB infection in their lungs coughs or sneezes and someone else inhales the expelled droplets, which contain TB bacteria.Although it is spread in a similar way to a cold or the flu, TB is not as contagious.owever, in some cases the bacteria infect the body but don't cause any symptoms (latent TB), or the infection begins to cause symptoms within weeks or months (active TB).