The potential impact of reductions in international donor funding on tuberculosis in low- and middle-income countries.

Background: Tuberculosis services in many settings rely heavily on international donor funding. In 2025, the United States Agency for International Development (USAID) was dismantled, and other countries also announced cuts to overseas development assistance. We quantified potential epidemiological impacts attributable to these reductions in international donor funding. Methods: We calibrated a deterministic tuberculosis model to epidemiological indicators in low- and middle-income countries. We projected three future scenarios assuming: a) levels of funding in 2024 continue through 2035, b) termination of USAID funding from 2025, and c) additional reductions in funding through The Global Fund in line with current donor announcements from 2025. We assumed a reduction in tuberculosis treatment initiation rates proportional to budget reductions for each scenario, estimating cumulative excess incident episodes of symptomatic tuberculosis and tuberculosis deaths. Findings: We modelled 79 countries, representing 91% of global tuberculosis incidence and 90% of global tuberculosis mortality in 2023. Our modelling suggested that the termination of USAID funding may lead to 420 500 excess tuberculosis deaths by 2035. Further reductions in funding in line with current announcements by the United States, France, the United Kingdom, and Germany may lead to an additional 699 200, 63 100, 50 500, and 30 500 TB deaths, respectively. Impacts would be greatest in low-income countries. Interpretation: We estimate substantial potential impacts on tuberculosis morbidity and mortality due to reductions in international donor funding. Expanded support from domestic and international donors is essential to address immediate gaps in prevention, diagnosis, and treatment. Funding: This work was unfunded.