P-563. Low level viremia is associated with viral non-suppression within 96 weeks among adolescents with perinatally acquired HIV: a prospective cohort study

Abstract

Abstract Background Viral suppression, defined as having a viral load (VL) < 1,000 cop/mL is used as the threshold for antiretroviral treatment (ART) changes in WHO guidelines. It is unclear whether those with low-level viremia (LLV) (VL 60-999 cop/mL) and undetectable (VL< 60) have different HIV-related outcomes. This study investigated factors associated with having viral non-suppression (≥1000 copies/ml) within 96 weeks among adolescents with perinatally-acquired HIV in Zimbabwe and Zambia with viral suppression (< 1000 copies/mL) at baseline. Methods Longitudinal analysis of data from a trial using vitamin D and calcium supplementation on adolescents with perinatally-acquired HIV aged 11-19 years established on ART for > 6 months. Participants were enrolled from public-sector HIV-clinics in Harare and Lusaka and VL were measured at baseline, 48 weeks and 96 weeks. Those who completed follow-up until 96 weeks and were virally suppressed at baseline were included in this analysis. Enhanced adherence counselling was provided to those with viral non-suppression at 48 and 96 weeks. Multivariate Poisson regression was used for analysis of the association of viral-non suppression with VL at baseline, adjusting for age and sex a priori. Results A total of 656 who had a VL< 1000 at baseline and complete follow-up were included in this analysis. Median age was 15.2 years, 54.6% were female, 90 (13.7%) had viral non-suppression within 96 weeks: 49 (7.5%) at week 48, and 43 (6.6%) at week 96. Viral non-suppression occurred among 18/54 (33.3%) of those who had LLV at baseline in comparison to 72/602 (12.0%) of those that were undetectable at baseline. Adjusting for age and sex, those with LLV were 2.3 times more likely to have viral non-suppression within 96 weeks (adjusted risk ratio 2.32, 95%CI 1.53-3.51) in comparison to those undetectable. In univariate analysis, country, age, sex, being enrolled in school and baseline ART regimen were not associated with having viral non-suppression within 96 weeks of follow up. Conclusion Adolescents with LLV are at higher risk of viral non-suppression within 96 weeks than those with undetectable VL, with implications for HIV transmissibility, resistance to ART and HIV-related clinical outcomes. Disclosures All Authors: No reported disclosures