The Contribution of TB Rapid Diagnostic Testing in Reducing TB- related Mortality in Sub-Saharan Africa- in both Person-Living with HIV and HIV-Negative Populations: An 8-year Quantitative Retrospective Analysis

Background The WHO, through the UN SDGs, developed a strategic roadmap to eliminate TB as a global public health problem by 2030, known as the “End-TB”. One key goal is to significantly reduce TB-related mortality. A potential contributor to achieve this goal is the role-out and scale-up of TB Rapid Diagnostic Testing (RDT). Our study evaluated the overall trend of TB disease burden in SSA, exploring the contribution of the WHO-recommended TB-NAATs to the reduction in TB-related mortality in both PLHIV and the HIV-negative population, from 2015–2023. Methods We carried out an 8-year quantitative retrospective analysis of country-level data for all countries in SSA reporting to the WHO. We retrieved data directly from the available annual WHO reports and entered them into the database for each country. We estimated the following parameters: incidence, notification, percentage of undiagnosed TB patients, percentage of TB-NAATs used, and TB-related mortality. We stratified the reports according to TB incidence and limited the analysis to reports where the percentage of undiagnosed individuals was 30% or less. We then used scatter plots to examine the existence of a relationship between the use of TB-NAATs and TB-related mortality. We quantified the observed relationships via linear regression models. Results Overall, SSA made great strides toward the 2025 milestones of End-Tb disease burden-related targets; TB disease incidence decreased by 14%; TB-related mortality decreased by 27.2%; and TB/HIV-related mortality decreased by 64.1%. TB-NAATs have become the priority TB disease diagnostic modality, at 66.0% in 2023. We found a consistent inverse relationship between RDT scale-up and TB-related mortality in the HIV-negative population, which was significantly stronger in the higher TB incidence strata (R2 = 0.69, P = 0.002732). In contrast, the relationship was weaker and inconsistent in the PLHIV population and was significant only where the TB incidence among PLHIV was very high (R2 = 0.54, P = 0.023861). Conclusions This study provides evidence of the contributions of TB RDTs to the decrease in TB-related mortality in SSA, highlighting the importance of maximum scaleup of TB-NAATs while addressing the problem of undiagnosed TB and limiting the biased prioritization of PLHIV for these RDTs.