What is tuberculosis?

Tuberculosis is a disease caused by an infection with the bacteria Mycobacterium tuberculosis. The disease is more common in areas of the world where poverty, malnutrition, poor health and social disorder are present.
The bacteria that cause the disease are inhaled (in form of particles that only can be seen by microscope) and come from a person with tuberculosis. When you cough, speak or sneeze, the small particles are expelled into the air. They dry out quickly, but the bacteria itself can remain flying for hours in the environment. However, the tuberculosis bacteria are killed when you are exposed to ultraviolet light, including sunlight (in a longer period of time).