Key Facts
In 2023, tuberculosis (TB) claimed the lives of 1.25 million individuals globally, including 161,000 who were also living with HIV. After three years of the coronavirus disease (COVID-19) being the dominant infectious killer, TB has likely regained its status as the leading cause of death from a single infectious agent. It also remains the top cause of mortality for people with HIV and contributes significantly to deaths attributed to antimicrobial resistance. Furthermore, approximately 10.8 million individuals fell ill with TB in 2023, comprising 6.0 million men, 3.6 million women, and 1.3 million children—and it affects all countries and age demographics. Nevertheless, TB is both preventable and treatable.
Multidrug-resistant TB (MDR-TB) persists as a significant public health challenge and poses a serious health security risk. In 2023, only about 40% of those afflicted with drug-resistant TB received necessary treatment. Global efforts to combat TB have successfully saved an estimated 79 million lives since the year 2000. An annual investment of US$ 22 billion is required for TB prevention, diagnosis, treatment, and care to achieve the global targets established at the 2023 United Nations high-level meeting on TB. The objective of ending the TB epidemic by 2030 is also a key part of the United Nations Sustainable Development Goals.
Overview
Tuberculosis (TB) is an infectious disease caused by bacteria that primarily affect the lungs. The disease spreads through the air when individuals with TB cough, sneeze, or spit. Importantly, TB can be prevented and effectively treated.
Approximately one-quarter of the global population is believed to have been infected with TB bacteria, although only about 5-10% of these individuals will develop symptoms and full-blown TB disease. Those who are infected but do not exhibit symptoms are not contagious. TB disease is typically treated with antibiotics, and without proper treatment, it can be fatal.
In select countries, the Bacille Calmette-Guérin (BCG) vaccine is administered to infants or young children to guard against TB, significantly reducing mortality and protecting against severe forms of the disease.
Certain conditions can increase the risk of developing TB, including:
- Diabetes (high blood sugar)
- Weakened immune systems (for instance, due to HIV/AIDS)
- Malnutrition
- Tobacco use
- Harmful alcohol consumption
Symptoms
Individuals infected with TB may not feel unwell and are not contagious. Only a small percentage of those infected with TB develop the disease and display symptoms, with babies and young children at greater risk.
TB disease occurs when bacteria multiply within the body, potentially affecting various organs. Symptoms may be mild for an extended period, allowing for the unintentional spread of TB. Some individuals with TB may show no symptoms.
Common symptoms of TB include:
- Prolonged cough (sometimes accompanied by blood)
- Chest pain
- Weakness
- Fatigue
- Weight loss
- Fever
- Night sweats
The manifestation of symptoms largely depends on the part of the body affected by TB, which most often includes the lungs, but can also impact the kidneys, brain, spine, and skin.
Prevention
To mitigate the risk of TB infection and transmission, consider the following:
- Seek medical attention for symptoms like a prolonged cough, fever, or unexplained weight loss, as early treatment is crucial for controlling the spread of the disease.
- If at high risk (such as being HIV-positive or in close contact with TB patients), get tested for TB. Preventive treatment can avert infection from progressing to disease.
- If diagnosed with TB, maintain good hygiene practices when coughing, including wearing a mask, covering your mouth and nose, and disposing of tissues responsibly.
- Implement special measures in healthcare settings, including the use of respirators and adequate ventilation to minimize the risk of transmission.
Diagnosis
The WHO recommends rapid molecular diagnostic tests to initially diagnose all individuals exhibiting signs of TB. Examples include the Xpert MTB/RIF Ultra and Truenat assays, known for their high diagnostic accuracy, which can significantly improve early detection rates for both TB and drug-resistant forms.
Additional tests, such as the tuberculin skin test (TST), interferon gamma release assay (IGRA), or newer antigen-based skin tests (TBST), can help identify individuals with TB infection. However, diagnosing multidrug-resistant TB and HIV-associated TB can be complex and costly, especially in children.
Treatment
Treatment for TB disease involves specialized antibiotics, which are also recommended for individuals with TB infection. The most frequently used antibiotics include:
- Isoniazid
- Rifampicin
- Pyrazinamide
- Ethambutol
For effective treatment, medications must be taken daily for 4 to 6 months. Unexpectedly stopping these medications can lead to drug resistance, worsening the situation.
Drug-resistant TB necessitates alternative medications, which may be more expensive and come with higher toxicity risks.
Multidrug-resistant TB (MDR-TB)
Drug resistance develops when TB medications are misused, whether through incorrect prescriptions, low-quality drugs, or premature treatment cessation.
MDR-TB arises from bacteria that resist isoniazid and rifampicin, the two most powerful first-line TB drugs. Fortunately, MDR-TB is treatable with alternative medications, albeit generally more costly and harmful.
In addition, extensively drug-resistant TB (XDR-TB) can occur when bacteria do not react to effective drugs in MDR-TB treatment protocols, leaving patients with few treatment avenues.
MDR-TB continues to be a significant public health dilemma, with only about 40% of patients accessing treatment in 2023.
As per WHO guidelines, diagnosing MDR-TB requires bacteriological confirmation of TB and drug resistance testing through rapid molecular or culture methods. In 2022, new WHO recommendations emphasized a shortened 6-month all-oral regimen known as BPaLM/BPaL for eligible patients. In 2023, treatment with the BPaLM/BPaL regimen increased substantially, demonstrating the promising potential of this approach to alleviate healthcare burdens and conserve resources.
TB and HIV
Individuals living with HIV face a startlingly higher risk—16 times more likely—to develop TB disease compared to those without HIV. TB remains the leading cause of mortality among people with HIV.
The coexistence of HIV and TB promotes the progression of both diseases. In 2023, about 161,000 individuals died from HIV-associated TB. 80% of notified TB patients had undergone an HIV test, maintaining the same proportion as in 2022 while rising from 76% in 2021. The WHO African Region has the highest incidence of HIV-associated TB, with only 56% of TB patients with known HIV status receiving antiretroviral therapy.
To combat TB-related deaths, WHO recommends a comprehensive, 12-part collaborative approach for TB-HIV activities focused on prevention and treatment.
Impact
TB predominantly impacts adults during their most productive years, yet all age groups are susceptible. Over 80% of incidences and fatalities occur in low- and middle-income nations.
TB affects every region globally; in 2023, the highest number of new cases was reported in the WHO South-East Asia Region (45%), followed by the African Region (24%) and the Western Pacific Region (17%). Approximately 87% of new TB cases were found in 30 high-burden countries, with significant numbers reported in Bangladesh, China, the Democratic Republic of the Congo, India, Indonesia, Nigeria, Pakistan, and the Philippines.
Worldwide, about half of all individuals treated for TB and their families experience catastrophic costs—defined as exceeding 20% of total household income—far from the WHO’s End TB Strategy goal of zero. Groups with weakened immune systems, such as those with HIV, malnutrition, diabetes, or tobacco use, have a heightened likelihood of developing TB. In 2023, it is estimated that 0.96 million new TB cases were linked to undernutrition, 0.75 million to alcohol use disorders, 0.70 million to cigarette smoking, 0.61 million to HIV infection, and 0.38 million to diabetes.
Investments to End TB
Annual funding of US$ 22 billion is essential for TB prevention, diagnostics, treatment, and care to meet global targets by 2027, as outlined during the 2023 UN high-level TB meeting.
Similar to previous years, the majority of funding for TB services in 2023 (80%) originated from domestic sources. However, international donor support remains vital in low- and middle-income countries. From 2019 to 2023, domestic funding decreased by US$ 1.2 billion, whereas international donor funding saw a modest rise of US$ 0.1 billion. The decline in domestic financing is largely attributed to falling contributions from Brazil, Russia, India, China, and South Africa (the BRICS countries). The budget for TB research and innovation, standing at US$ 1 billion in 2022, remains considerably below the global target of US$ 5 billion per year, reflecting an inherent investment shortfall.
WHO Response
The WHO collaborates with nations, partners, and civil society to enhance the global TB response. Six fundamental functions are being pursued to meet the targets established at the 2023 UN high-level meeting political declaration, the Sustainable Development Goals, and the WHO’s broader strategic priorities:
- Providing global leadership to eliminate TB through strategic development, political commitment, multisectoral engagement, advocacy, and partnerships with civil society.
- Shaping the research and innovation landscape around TB and facilitating the dissemination of knowledge.
- Establishing norms and standards for TB prevention and care while promoting their implementation.
- Creating ethical, evidence-based policy options for TB management and care.
- Offering specialized technical support to member states and partners in partnership with WHO regional and country offices, fostering change and building sustainable capabilities.
- Monitoring and reporting on the TB epidemic’s status, as well as the financial and operational progress at global, regional, and national levels.
