Factors associated with viral suppression and antiretroviral therapy adherence among adolescents and young adults living with HIV in the African Cohort Study

INTRODUCTION: Adolescents and young adults living with HIV (AYLHIV) experience poor outcomes across the care continuum, and most reside in sub-Saharan Africa. The African Cohort Study (AFRICOS) provides an opportunity to examine HIV outcomes in this population across Kenya, Nigeria, Tanzania, and Uganda. METHODS: We conducted a cross-sectional analysis of AYLHIV aged 15-29 years, enrolled in AFRICOS 2013-2023, and on antiretroviral therapy (ART) ≥ six months. Primary outcomes were HIV viremia and 30-day ART non-adherence. Factors included HIV acquisition route, ART duration, ART class, and site. We used multivariate robust Poisson regression to estimate relative risks (RRs) and 95% confidence intervals (CIs). Site directors were surveyed to assess youth-friendly services. RESULTS: Among 656 participants, the median age was 20.0 years (IQR 17.5-23.3); 41.6% were male, 61.6% had perinatally-acquired HIV, and median duration since HIV diagnosis was nine years. At enrollment, 83.8% had viral suppression (<200 copies/mL) and 80.2% were ART adherent. ART regimen and clinic site were associated with viral suppression: youth on integrase vs. protease inhibitor-based regimens (adjusted relative risk (aRR) 0.38, CI 0.23-0.63, p<0.001), and in Uganda (aRR 0.42, CI 0.20-0.90, p=0.026) or Kisumu, Kenya (aRR 0.40, CI 0.22-0.76, p=0.005) had lower likelihood of non-suppression. Compared to Nigeria, participants from other sites were less likely to report non-adherence (unadjusted RR 0.31-0.44). Youth-friendly service provision varied. CONCLUSIONS: Viral suppression and ART adherence were high among AYLHIV in AFRICOS. Clinic site and ART regimen were associated with outcomes, highlighting the importance of health system factors.