Trends and regional disparities in TB-HIV co-infection and ART coverage across 30 African countries from 2009 to 2023: a spatio-temporal analysis

Abstract

Tuberculosis and Human Immunodeficiency Virus co-infection is a significant global public health challenge, particularly in Africa. Despite the expansion of ART in Africa, there are notable disparities in the burden of TB-HIV co-infection and ART access. However, there is limited evidence that combines long-term trends with spatial differences across African countries. This study conducted a retrospective analysis of data from 30 African countries between 2009 and 2023, utilizing the WHO’s Global Tuberculosis Database. It employed a Bayesian hierarchical spatio-temporal model to investigate the relationship between ART coverage and TB-HIV co-infection, accounting for both spatial dependence and temporal correlation. Model performance was assessed using DIC and WAIC. From 2009 to 2023, there was a significant decline of over 41% in the continental mean TB-HIV co-infection prevalence, dropping from 37.1% to 22.0%. While ART coverage increased, it varied significantly, with some Southern African Countries facing the highest co-infection rates, compared to West and North Africa with lower levels. ART coverage was notably higher in Southern and parts of Eastern Africa, while West Africa showed lower coverage. The Bayesian model revealed a weak and statistically non-significant population-level association between ART coverage and TB-HIV co-infection prevalence, demonstrating that temporal trends were baseline flat and that the vast majority of the variance was captured by unobserved heterogeneity at the country level rather than by residual spatial or temporal clustering. Despite progress in reducing TB-HIV co-infection in Africa, regional disparities remain. The empirical findings indicate that the continental decrease cannot be statistically attributed to ART scale-up at the population level, highlighting the need for integrated TB-HIV services, improved health systems, and tailored interventions. Spatially targeted strategies focused on country-specific structural dynamics are crucial to address persistent hotspots and inequities in TB-HIV burdens across Africa.