Comparative 48-Week Viral Load Suppression across Antiretroviral Initiation Regimens: Dolutegravir versus Non-Dolutegravir among People Living with HIV in Tanzania

Abstract Background Routine viral load monitoring is central to assessing treatment effectiveness in HIV care, and dolutegravir (DTG)-based regimens are now preferred in many treatment programmes. However, national routine data analyses comparing 48-week viral load suppression across antiretroviral therapy initiation regimens in Tanzania remain limited. Methods We conducted a retrospective cohort analysis using routinely collected HIV programme data from Tanzania’s National AIDS, STIs and Hepatitis Control Programme database. After de-duplication and data processing, the working analysis warehouse contained 49,547 patients and 1,008,137 visits. The primary analysis included 6,991 patients with a valid viral load measured 48 weeks after initiation of antiretroviral therapy. Viral suppression was defined as a viral load <1,000 copies/mL. We compared suppression between DTG-based and non-DTG-based initiation groups and across individual initiation regimens. Treatment change episodes and early DTG switching patterns were summarized as secondary analyses. Results Of the 6,991 included patients, 6,113 (87.4%) achieved viral load suppression at 48 weeks. Suppression was higher among DTG initiators than non-DTG initiators (917/1,000, 91.7% vs. 5,196/5,991, 86.7%). TDF+3TC+EFV was the most common non-DTG initiation regimen, whereas TDF+3TC+DTG was the most common regimen among DTG initiators. Conclusions Viral suppression at 48 weeks was high overall but was higher among patients initiated on DTG-based regimens than among those initiated on non-DTG regimens. By anchoring outcomes to a fixed post-initiation time point, this study complements existing Tanzanian evidence on viral load testing uptake and geographic variation. It provides regimen-specific insights into the effectiveness of early treatment under routine programme conditions.