The Global Health Challenge of Tuberculosis (TB)
TB remains a leading cause of death worldwide due to challenges in prevention, screening, diagnosis, and treatment adherence. There is also a growing burden of TB drug resistance, adding to the urgent need to address these challenges.
TB disproportionately affects low- and middle-income countries (LMICs). There, most people with TB symptoms enter the health system at primary health care (PHC) facilities. These facilities typically only handle TB screening, with patient samples collected at the PHC level and sent out to a higher-level facility for diagnosis. This sample transfer step delays diagnosis and causes loss to follow-up. Reducing the burden of TB requires innovation for screening and diagnosis at the PHC level where patients first seek care. TB is treatable, and missed diagnosis is currently the most critical gap to fill, with tools and equipment needed that can be effectively used for care at the PHC level.
Etiology
TB is an Infectious Bacterial Disease
TB is an infectious disease caused by the bacterium Mycobacterium tuberculosis. It spreads through the air when an infected person with active TB coughs or sneezes, releasing bacteria-laden droplets that others can inhale. Once inhaled, the bacteria settle in the lung alveoli, where they are engulfed by white blood cells, marking the primary TB infection. Only 5% of people with intact immunity develop active TB disease, while the remainder harbor latent bacteria that can become active under immunosuppressive conditions such as HIV, diabetes, or malnutrition.
TB primarily affects the lungs but can also impact other organs. It is preventable, and it is treatable with antibiotics. Effective screening, early diagnosis, and proper treatment and treatment adherence are crucial to prevent the spread of TB disease and drug resistance and address its social and economic burden.
Disease Burden
TB is a Leading Cause of Death Worldwide
Approximately 10.8 million people fell ill with TB in 2023, the highest number since monitoring began in 1995. There were 1.25 million deaths, including 161,000 people living with HIV, for whom TB is the leading cause of death. For more details, see the WHO Global tuberculosis report 2024.
Of the new TB cases in 2023, 87% occurred in the 30 high TB burden countries, with over two-thirds of global cases concentrated in eight countries: India (26%), Indonesia (10%), China (6.8%), the Philippines (6.8%), Pakistan (6.3%), Nigeria (4.6%), Bangladesh (3.5%), and the Democratic Republic of the Congo (3.1%). Multidrug-resistant TB (MDR-TB) remains a significant public health threat, with only 2 in 5 people with MDR-TB accessing care in 2023. Country level disease burden can be found here.
Countries Have Opportunities in Common to Improve TB Care
Rapid and accurate diagnosis of TB and drug resistance at the point of patient care is crucial to stop the spread of TB. LMICs vary in their reliance on TB diagnosis by microscopy versus molecular testing that can also detect drug resistance. Despite these differences, there is a shift in common across countries towards more advanced diagnostic methods. This highlights opportunities for innovation to improve TB diagnostics and other elements of the TB cascade of care in each country's context. StopTB also publishes country-level assessments of digital TB surveillance systems for 19 countries.
The selected countries illustrate different diagnostics testing models: Kenya employs a decentralized model, placing diagnostic testing capabilities directly in decentralized settings; South Africa follows a more centralized model, where samples are collected at the PHC level and sent to centralized laboratories, and Nigeria, as the most populous African country, represents a large and growing market for diagnostic testing.
India
Kenya
Nigeria
South Africa
Patient Experience
Primary Health Care is Essential for TB Control
Learn more about the patient experience across the cascade of TB care
Technology Solutions
New Tools and Equipment are Needed for TB Care
Learn more about how GH Labs and others are addressing the key technical gaps in the TB cascade of care