Uptake and predictors of viral load testing and viral suppression among people receiving antiretroviral therapy in mainland Tanzania

Abstract Background Routine viral load monitoring is essential for assessing treatment effectiveness and for achieving global HIV treatment targets. Although viral load testing capacity has expanded across sub-Saharan Africa, gaps remain in monitoring coverage and equitable treatment outcomes. National-level analyses examining viral load uptake, suppression, and geographic variation in Tanzania remain limited. Methods We conducted a retrospective observational analysis using routinely collected HIV programme data from the National AIDS and Sexually Transmitted Infections Control Programme (NASHCoP) Care and Treatment Clinic database. The analysis included 70,000 individuals receiving antiretroviral therapy between 2017 and 2021 across all regions of mainland Tanzania. Viral load uptake was defined as the presence of at least one documented viral load test during the observation period. Viral suppression was defined as a viral load result <1,000 copies/mL among individuals with available test results. Descriptive analyses summarized demographic and treatment characteristics, while multivariable logistic regression models identified predictors of viral load uptake and viral suppression. Geographic variation in programme performance was examined at regional and district levels using choropleth maps. Results Among 70,000 individuals included in the analysis, 49,820 (71.2%) had at least one documented viral load result. Among those tested, 44,187 (88.7%) achieved viral suppression. Viral load uptake was lowest among young adults and slightly lower among males than females. Viral suppression was lower among children and adolescents than among older age groups. Individuals receiving dolutegravir-based regimens demonstrated higher viral suppression than those receiving NNRTI-based regimens. Substantial geographic heterogeneity was observed, with viral load uptake varying across regions and districts. Several districts characterized by mobile populations and seasonal migration patterns demonstrated comparatively lower monitoring coverage. Conclusions Although viral load monitoring coverage and suppression levels among those tested were relatively high, important gaps remain in testing uptake and geographic equity. Adolescents, young adults, and populations in certain districts experience lower monitoring coverage and treatment outcomes. Strengthening viral load monitoring systems, expanding youth-responsive HIV services, and addressing geographic disparities will be important for sustaining progress toward national and global HIV treatment targets.