Global Tuberculosis Burden and Mortality
Tuberculosis remains one of the top infectious killers worldwide, with the World Health Organization reporting an estimated 1.3 million deaths among HIV-negative people in 2022 and an additional 167,000 deaths among HIV-positive individuals. The WHO Global Tuberculosis Report 2023 notes that TB incidence declined only modestly before the pandemic, and progress toward the 2030 targets set in the Sustainable Development Goals has slowed. The disease disproportionately affects low- and middle-income countries, with India, Indonesia, China, the Philippines, and Nigeria accounting for more than half of all cases. For investors tracking health equities and biotech pipelines, the persistent TB burden highlights long-term demand for diagnostics, drugs, and vaccines, as outlined by organizations such as the Global Fund to Fight AIDS, Tuberculosis and Malaria https://www.theglobalfund.org/en/.
Mortality rates vary sharply by region and population group. In 2022, the WHO estimated a global TB incidence of about 10.6 million cases, with the highest rates in parts of sub-Saharan Africa and South Asia. Drug-resistant TB, particularly multidrug-resistant and rifampicin-resistant forms, remains a severe threat, with an estimated 450,000 incident cases in 2022. Treatment success rates for drug-susceptible TB remain above 85% when patients complete standard six-month regimens, but outcomes drop for drug-resistant strains without effective newer regimens such as the BPaL regimen recommended by regulatory authorities in recent years. The high cost of failure for both health systems and patients is well documented by the Stop TB Partnership https://www.stoptb.org/.
Transmission, Risk Factors, and Pathogenesis
Tuberculosis is caused by Mycobacterium tuberculosis and spreads through airborne droplets when an infectious person coughs or sneezes. Only people with active pulmonary TB are typically contagious, and prolonged close contact is usually required for transmission. Risk factors include HIV co-infection, malnutrition, diabetes, tobacco use, alcohol use disorder, and indoor air pollution. Crowded living conditions, incarceration, and migration from high-burden settings further increase exposure risk. Companies developing rapid molecular diagnostics, such as Cepheid’s GeneXpert systems, have expanded point-of-care testing in many high-burden countries, as described by the WHO https://www.who.int/news-room/fact-sheets/detail/tuberculosis.
Pathogenesis begins when inhaled bacilli reach the alveoli and are phagocytosed by macrophages, but M. tuberculosis can survive and multiply inside these cells. The immune system often walls off the bacteria in granulomas, leading to latent TB infection, which affects roughly one quarter of the world’s population according to WHO estimates. About 5 to 10 percent of people with latent infection will develop active TB disease over their lifetime, with the highest risk in the first two years after infection and in individuals with compromised immunity. Newer vaccine candidates, including M72/AS01E, have shown promising efficacy in preventing pulmonary TB in adults with latent infection in clinical trials reported in 2023 https://www.nejm.org/doi/full/10.1056/NEJMoa2300341.
Treatment, Innovation, and Economic Impact
Standard treatment for drug-susceptible TB uses a six-month regimen of first-line antibiotics, typically isoniazid, rifampicin, ethambutol, and