Population level impact of increasing tuberculosis treatment coverage and addressing determinants of risk in men: a modelling study in Kenya, Malawi, Nigeria, and Uganda

BackgroundGlobally, the burden of tuberculosis (TB) falls more on men than women and children, and there are large gaps between men and women at all stages of exposure, disease incidence, and treatment. We examined the impact of addressing determinants of these gender gaps in Kenya, Malawi, Nigeria, and Uganda. Methods and FindingsWe created a deterministic transmission model of TB, with strata for sex, age, and HIV co-infection and antiretroviral therapy, and calibrated to country-specific data on prevalence, incidence, mortality, and notifications between 2010 and 2022. We then examined the potential epidemiological impact of strategies to increase treatment coverage among men, and decrease the effects of social and structural determinants that increase mens risk of developing TB. We investigated impact (overall and by age and sex) on projected incidence and mortality in 2035, and notification rates between 2025 and 2030. Relative reductions in overall TB incidence from increased treatment coverage among men ranged from 4.8% [95% uncertainty interval (UI)0.7-10.6%] in Malawi to 24.8% [UI 14.3-37.0%] in Uganda. Reducing mens excess risk of TB led to a similar range in relative reductions from 8.4% [UI 6.6-10.4%] in Nigeria to 23.3% [UI 18.0-30.0%] in Uganda. Combining strategies increased the relative reduction beyond that seen with one strategy alone, but as would be anticipated by greater prevention of incident TB, less than the sum of both strategies. Impacts extended across the population with median estimates of country-level declines in incidence of between 1.6--10.6% and 2.8--19.5% in women and children respectively, across the four countries. Increasing treatment coverage increased the median country-level estimates of notifications between 3.1% and 12.4% in the first three years, however combining increased treatment coverage with a reduction in risk reduced the median annual country-level notifications by 6.7% to 18.1% by 2035. ConclusionStrategies that prioritise increasing TB treatment coverage among men and mitigating mens higher susceptibility to TB could reduce disease burden for men, women, and children. Such gender-responsive strategies are essential to ensure a person-centred TB response and accelerate global progress towards the End TB targets.