Tracking viral control in adolescents on antiretroviral therapy in Lusaka, Zambia: A retrospective cohort analysis

Abstract

Background: In 2023, an estimated 39.9 million people globally were living with HIV, of which 1.55 million were adolescents aged 10–19 years. The 2021 Zambia HIV Impact Assessment revealed lower viral suppression rates in adolescents (15–24 years old) compared to adults on antiretroviral therapy (ART). Lusaka District, Zambia, has the highest number of adolescents on ART, with a 15.1% HIV prevalence in 2018.

Objectives: To determine the prevalence and factors associated with viral suppression among adolescents living with HIV (10–19 years) on ART in Lusaka District, Zambia.

Method: A retrospective cohort analysis was done of 3409 adolescents on ART at public health facilities in Lusaka from January 2023 to December 2023, and who had viral loads recorded. Socio-demographic, clinical, treatment and behavioural data were extracted from electronic health records and analysed using SPSS version 29.

Results: The adolescent cohort in Lusaka achieved 91.8% viral suppression rate (< 1000 copies/mL), with 79% fully suppressed (< 50 copies/mL). In multivariate analysis, older adolescents (15–19 years) had lower odds of suppression compared to younger adolescents (10–14 years) (adjusted odds ratio [AOR] = 1.79; confidence interval [CI] : 1.32–2.43). Higher odds of viral suppression were linked to first-line dolutegravir regimen (AOR = 5.12; CI: 3.23–8.11) and optimal adherence (AOR = 1.89; CI: 1.03–3.47), while regimen switches reduced the odds of viral suppression (AOR = 0.60; CI: 0.45–0.80).

Conclusion: Zambia reached the previous UNAIDS 90-90-90 targets with a viral suppression rate of 91.8%. However, to reach the revised 95% target by 2030, tailored interventions should be implemented to improve adherence and retention in care, particularly for older adolescents.