Tuberculosis (TB) is a disease caused by:
Together they form the Mycobacterium tuberculosis complex (MTBC).
There are two forms of TB.
Active tuberculosis is the condition in which MTBC causes infection. It usually affects the lungs (pulmonary TB). It can also cause infection elsewhere in the body, including but not restricted to bones, gastrointestinal, and nervous systems.
This is the condition in which MTBC causes disease.
It usually affects the lungs (pulmonary TB).
It can also cause infection elsewhere in the body, including but not restricted to:
This is where a person is infected with but does not have TB disease.
This is often referred to as latent TB infection or LTBI.
The person is not infectious to others and cannot spread TB.
Without treatment, around 5 to 10% of infected persons will develop active TB disease at some point in their lives.
The World Health Organization estimates that, annually, around 8 million people develop active tuberculosis globally, and nearly 2 million people die from the disease.
Find out about the Stop TB Partnership's Global Plan to end TB.