Tuberculosis (TB) is a communicable disease that is a major cause of ill health, one of the top 10 causes of
death worldwide and the leading cause of death from a single infectious agent (ranking above HIV/AIDS). In
2019, about 10 million people developed TB and 1.4 million died. TB is caused by the bacillus Mycobacterium tuber- culosis, which is spread when people who are sick with TB expel bacteria into the air; for example, by coughing. The disease typically affects the lungs (pulmonary TB) but can also affect other sites (extrapulmonary TB).
TB can affect anyone anywhere, but most people who develop the disease (about 90%) are adults; there are
more cases among men than women; and of those who fell sick with TB in 2019, 87% were in 30 high TB burden countries. Case rates at national level vary from less than 5 to more than 500 per 100 000 population per year.
TB is a disease of poverty, and economic distress, vulnerability, marginalization, stigma and discrimination
are often faced by people affected by TB. About a quarter of the world’s population is infected with M.
tuberculosis.Globally, an estimated 10.0 million (range, 9.0–11.1 million) people fell ill with TB in 2019. The burden of disease varies enormously among countries, from fewer than five to more than 500 new cases per 100 000 population per year.