Factors associated with viral load suppression among Children and Adolescents on Dolutegravir based Antiretroviral regime in Tanzania: a longitudinal analysis

Introduction: Antiretroviral therapy (ART) reduces morbidity and mortality due to human immunodeficiency virus (HIV) infection. In 2019, Tanzania adopted Dolutegravir (DTG) as a first-, second-line, and third-line treatment for children and adolescents living with HIV (CALHIV). Viral load suppression (VLS) is desirable in the prevention of HIV transmission thus achieving the third ‘95’ target. DTG treatment has highly potent antiviral activity, a high genetic barrier to resistance, and a high safety profile. We aimed to determine VLS and associated factors among CALHIV on DTG-based ART in Tanzania. Methods We conducted a retrospective cohort analysis among CALHIV who were on a DTG-based regimen in Tanzania between 2019 and 2021. We extracted demographic and clinical characteristics from the care and treatment clinic database. A multilevel mixed effects model of family Poisson was used to account for health facility random effects to determine the proportion of VLS at < 1000 copies/ml and its factors associated with CALHIV on a DTG-based regimen. Results A total of 63,453 CALHIV on a DTG-based regimen were analysed. The proportion of viral suppression was 91.64%. Overall, 66.19% of previously unsuppressed individuals became suppressed and 88.45% of previously suppressed remained suppressed. Factors leading to lower chances of viral suppression were age 10–14 years (aRR: 0.98; 95%CI: 0.97–0.99), previously unsuppressed prior to starting DTG (aRR: 0.92; 95%CI: 0.91–0.93), duration on ART more than 24 months (aRR: 0.96; 95%CI: 0.94–0.97), not retained in care (aRR: 0.83; 95% CI: 0.77–0.89), severe malnutrition (aRR:0.77; 95%CI: 0.69–0.94) and coastal zone (aRR: 0.98; 95% CI: 0.96–0.99), while those in WHO stage I (aRR: 1.03; 95%CI: 1.01–1.04) and ever received a multi-month prescription (aRR: 1.25; 95% CI: 1.23–1.28) were more likely to achieve VLS. Conclusions This study showed DTG-based regimens have a good response for both naïve, previously unsuppressed, and suppressed Children and Adolescents Living with HIV (CALHIV) with significant improvement in viral suppression. Improving retention in care and malnutrition might improve VLS and achieve the third ‘95’.