Population Viral Load Suppression and Associated Factors in Tanzania: Findings From 2 Sequential Tanzania HIV Impact Surveys of 2016-2017 and 2022-2023.

BACKGROUND: Antiretroviral therapy improves outcomes for people living with HIV (PLHIV) and prevents transmission through viral load suppression (VLS). To evaluate progress toward HIV epidemic control, VLS prevalences and correlates among PLHIV were analyzed from Tanzania HIV Impact Assessment Surveys (THIS), independent, cross-sectional using stratified-cluster design, conducted in 2016-2017 (S1) and 2022-2023 (S2). METHODS: Participants 15 years and older provided consent, completed an interviewer-administered questionnaire, and tested for HIV using the national rapid testing algorithm. HIV-positive specimens were tested for viral load. Prevalence of population VLS (<1000 copies/mL) was determined irrespective of HIV-knowledge or antiretroviral therapy status. Modified Poisson Regression Model was used. We reported percentages (%) and adjusted prevalence ratios with 95% confidence intervals (CIs) accounting for complex survey design. RESULTS: We analyzed data from 1830 PLHIV in S1 and 1849 in S2. Population VLS prevalence increased by 26.1% (95% CI: 22.1 to 30.2, P < 0.0001) between surveys. In both surveys, women were more likely to experience VLS [S1: 1.43 (95% CI: 1.25 to 1.63), S2: 1.15 (95% CI: 1.06 to 1.24)] than men. In both surveys, PLHIV 35 years and older were more likely to experience VLS than those 15-24 years, [S1 35-49 years: 1.46 (95% CI: 1.13 to 1.90), 50 years and older: 1.69 (95% CI: 1.28 to 2.23), and S2 35-49 years: 1.31 (95% CI: 1.06 to 1.62), 50 years and older: 1.42 (95% CI: 1.15 to 1.76)]. CONCLUSION: Tanzania has made progress toward HIV epidemic control, as evidenced by the significant increase in VLS prevalence in 6 years. Targeted sex-age strategies are essential for HIV epidemic control.