Tuberculosis (TB) is an infectious disease caused by a bacterium called Mycobacterium tuberculosis (MTB). It affects mainly the lungs, but can also affect any other organs in the body.

More than 2 billion people, one-third of the world's population, are infected with TB bacilli, over 90 percent of them in developing countries. The vast majority of TB deaths are in the developing world, with more than half of all deaths occurring in Asia. Due to a combination of economic decline, the breakdown of health systems, insufficient application of TB control measures, the spread of HIV/AIDS and the emergence of multi-drug resistant TB (MDR-TB), TB remains a major health problem in low-middle income countries.

Globally, men account for a higher proportion of notified TB cases (64 percent). However, TB is a leading cause of death among women of reproductive age.

Children are also particularly vulnerable to TB. HIV and TB form a lethal combination, each speeding the other's progress. Africa accounted for 85 percent of the estimated global HIV-positive TB cases. TB infection can be prevented, treated and contained.

WHO and the Stop TB Partnership recommend an approach to reducing the burden of TB in line with global targets called the Stop TB Strategy.