Tuberculosis (TB) is an infectious disease caused by bacteria that most often affects the lungs. It spreads through the air when people with TB cough, sneeze or spit.
Tuberculosis is preventable and curable.
About a quarter of the global population is estimated to have been infected with TB bacteria. About 5–10% of people infected with TB will eventually get symptoms and develop TB disease.
Those who are infected but free of disease cannot transmit it. TB disease is usually treated with antibiotics and can be fatal without treatment.
In certain countries, the Bacille Calmette-Guérin (BCG) vaccine is given to babies or small children to prevent TB. The vaccine prevents deaths from TB and protects children from serious forms of TB.
Certain conditions can increase a person’s risk for TB disease:
People with TB infection don’t feel sick and aren’t contagious. Only a small proportion of people who get infected with TB will get TB disease and symptoms. Babies and children are at higher risk.
TB disease occurs when bacteria multiply in the body and affect different organs. TB symptoms may be mild for many months, so it is easy to spread TB to others without knowing it. Some people with TB disease do not have any symptoms.
Common symptoms of TB are:
The symptoms people get depend on which part of the body is affected by TB. While TB usually affects the lungs, it can also involve the kidneys, brain, spine and skin.
Follow these steps to help prevent tuberculosis infection and spread:
WHO recommends the use of rapid molecular diagnostic tests as the initial diagnostic test in all persons with signs and symptoms of TB.
Rapid diagnostic tests recommended by WHO include the Xpert MTB/RIF Ultra and Truenat assays. These tests have high diagnostic accuracy and will lead to major improvements in the early detection of TB and drug-resistant TB.
A tuberculin skin test (TST), interferon gamma release assay (IGRA) or newer antigen-based skin tests (TBST) can be used to identity people with infection.
Diagnosing multidrug-resistant and other resistant forms of TB (see multidrug-resistant TB section below) as well as HIV-associated TB can be complex and expensive.
Tuberculosis is particularly difficult to diagnose in children.
Tuberculosis disease is treated with special antibiotics. Treatment is recommended for both TB infection and disease.
The most common antibiotics used are:
To be effective, medications need to be taken daily for 4–6 months. It is dangerous to stop the medications early or without medical advice as it can prompt TB bacteria in the body to become resistant to the drugs.
TB that doesn’t respond to standard drugs is called drug-resistant TB and requires treatment with different medicines.
Drug resistance emerges when TB medicines are used inappropriately, through incorrect prescription by health care providers, poor quality drugs, or patients stopping treatment prematurely.
MDR-TB is a form of TB caused by bacteria that do not respond to isoniazid and rifampicin, the two most effective first-line TB drugs. MDR-TB is treatable and curable by using other drugs, which tend to be more expensive and toxic.
In some cases, extensively drug resistant TB or XDR-TB can develop. TB caused by bacteria that do not respond to the most effective drugs in MDR-TB treatment regimens can leave patients with very limited treatment options.
MDR-TB remains a public health crisis and a health security threat. Only about 2 in 5 people with multidrug resistant TB accessed treatment in 2023.
In accordance with WHO guidelines, detection of MDR-TB requires bacteriological confirmation of TB and testing for drug resistance using rapid molecular tests or culture methods.
In 2022, new WHO guidelines prioritized a short 6-month all-oral regimen known as BPaLM/BPaL as a treatment of choice for eligible patients. Globally in 2023, 5646 people with MDR/RR-TB were reported to have been started treatment on the BPaLM/BPaL regimen, up from 1744 in 2022. The shorter duration, lower pill burden and high efficacy of this novel regimen can help ease the burden on health systems and save precious resources to further expand the diagnostic and treatment coverage for all individuals in need. In the past, MDR-TB treatment used to last for at least 9 months and up to 20 months. WHO recommends expanded access to all-oral regimens.
People living with HIV are 16 (uncertainty interval 14–18) times more likely to fall ill with TB disease than people without HIV. TB is the leading cause of death among people with HIV.
HIV and TB form a lethal combination, each speeding the other’s progress. In 2023, about 161 000 people died of HIV-associated TB. The percentage of notified TB patients who had a documented HIV test result in 2023 was 80%, this was the same level as in 2022, but up from 76% in 2021. The WHO African Region has the highest burden of HIV-associated TB. Overall in 2023, only 56% of TB patients known to be living with HIV were on antiretroviral therapy (ART).
WHO recommends a 12-component approach of collaborative TB-HIV activities, including actions for prevention and treatment of infection and disease, to reduce deaths.
TB mostly affects adults in their most productive years. However, all age groups are at risk. Over 80% of cases and deaths are in low- and middle-income countries.
TB occurs in every part of the world. In 2023, the largest number of new TB cases occurred in the WHO South-East Asia Region (45%), followed by the African Region (24%) and the Western Pacific Region (17%). Around 87% of new TB cases occurred in the 30 high TB burden countries, with more than two-thirds of the global total in Bangladesh, China, Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan and the Philippines.
Globally, about 50% of people treated for TB and their households face total costs (direct medical expenditures, non-medical expenditures and indirect costs such as income losses) that are catastrophic (>20% of total household income), far from the WHO End TB Strategy target of zero. Those with compromised immune systems, such as people living with HIV, undernutrition or diabetes, or people who use tobacco, have a higher risk of falling ill. Globally in 2023, there were estimated 0.96 million new TB cases that were attributable to undernutrition, 0.75 million to alcohol use disorders, 0.70 million to smoking, 0.61 million to HIV infection, and 0.38 million to diabetes.
US$ 22 billion are needed annually for TB prevention, diagnosis, treatment and care to achieve global targets by 2027 agreed on at the 2023 UN high level-TB meeting.
As in the past decade, most of the spending on TB services in 2023 (80%) was from domestic sources. In low- and middle-income countries, international donor funding remains crucial. From 2019 to 2023, there was a decline (of US$ 1.2 billion) in available funding from domestic sources and a very slight increase (of US$ 0.1 billion) in funding provided by international donors. Most of the reduction in domestic funding is largely explained by reductions in domestic funding trends in Brazil, the Russian Federation, India, China and South Africa (BRICS). Financing for TB research and innovation at US$ 1.0 billion in 2022 also continues to fall far short of the global target of US$ 5 billion per year, constrained by the overall level of investment.
WHO is working closely with countries, partners and civil society in scaling up the TB response. Six core functions are being pursued by WHO to contribute to achieving the targets of the 2023 UN high-level meeting political declaration, Sustainable Development Goals, End TB Strategy and WHO strategic priorities:
