what causes tuberculosis (tb)
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.he 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.