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).
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. There were an estimated 1.2 million TB deaths among HIV-negative people in 2019 (a 27% reduction from 1.7 million in 2000), and an additional 208,000 deaths among HIV-positive people. The burden of drugresistant TB is of major concern at global, regional and country level. In 2019, 3.3% of new TB cases and 18% of previously treated cases had MDR/RR-TB, accounting for a global burden of half a million new cases of rifampicin-resistant TB (RR_TB), amongst which 78% multidrug-resistant TB. A total of 7.1 million new cases (70%) of TB were notified in 2019, and most of the increase in global notifications of TB cases since 2013 is explained by trends in India and Indonesia.