Barriers to viral load suppression among adolescents living with HIV on anti-retroviral therapy: a retrospective study in Tanga, Tanzania.

Background: Despite the decreased incidence of the human immunodeficiency virus (HIV) in Tanzania, the number of adolescents living with HIV is increasing. This study aimed to describe factors independently associated with viral load non-suppression among adolescents living with HIV (ALHIV) on ART in the Tanga region.

Methods: We conducted a retrospective study of routinely collected data from ALHIV on ART from October 2018 to April 2022. We extracted data from the Care and Treatment Clinics form number 2 (CTC2) database that included age, sex, BMI, World Health Organization HIV clinical disease stage, marital status, ART duration, viral load suppression, facility level, and Dolutegravir (DTG)-based regimen. We did descriptive analysis using frequencies to describe the study participants' socio-demographic and clinical characteristics. The Cox proportional hazard regression model was used to identify factors associated with viral load non-suppression (VLS). Viral load non-suppression was defined as viral load ≥ 1000 copies/ml. A total of 4735 ALHIV on ART were extracted from CTC2, then 2485 were excluded (2186 missed viral load results, 246 were lost to follow-up, and 53 deaths).

Results: 2250 ALHIV on ART were tested for viral load, of whom 2216 (98.62%) adolescents were on first-line ART, and 2024 (89.96%) participants were virally suppressed, while 226 (10.04%) were virally non-suppressed. In addition, 2131 (94.71%) of participants were using a DTG-based regimen; of them, 1969 (92.40%) were virally suppressed. Not using a DTG-based regimen (HR: 9.36, 95% CI 3.41-15.31) and dispensary facility level (HR: 3.61, 95% CI 1.44-7.03) were independently associated with increased hazard for viral load non-suppression. In addition, adolescents aged between 15 and 19 years are less likely to be virally suppressed (HR: 0.55, 95% CI 0.30-0.99).

Conclusions: The dispensary facility level and not using a DTG-based regimen were significantly associated with viral load non-suppression. HIV intervention strategies should ensure a DTG-based regimen utilization in all adolescents living with HIV, and techniques used by higher-level health facilities should be disseminated to lower-level facilities.