IntroductionAdolescents living with HIV (ALWH) face an elevated risk of poor health outcomes when transitioning into adult-oriented care; however, evidence-based interventions to support ALWH during this high-risk period are lacking, especially in Latin America. We conducted a pilot study of a community-based intervention designed to improve outcomes among ALWH transitioning to adult HIV care in Lima, Peru.MethodsFrom October 2019 to January 2020, we enrolled adolescents transitioning to adult HIV care, either due to a recent diagnosis or having aged out of their pediatric clinic. ALWH previously lost from care during the transition process were also invited to participate. The nine-month intervention consisted of (1) logistical, adherence and social support delivered by entry-level health workers who accompanied adolescents during their transition to adult HIV care and (2) group sessions to improve health-related knowledge, skills and social support. We assessed intervention feasibility and effectiveness in improving medication adherence, psycho-social outcomes, and transition readiness after 6, 9, and 12 months.ResultsWe enrolled 30 ALWH, ages 15-21 years; 11 were recently diagnosed and 19 had been living with HIV since infancy or early childhood. Participants included ten men who have sex with men, four young pregnant women and six adolescents who were previously lost during the transition to adult HIV care. Intervention participation was high with 90% of ALWH attending at least one in-person social support session and all attending at least one live online session. No ALWH withdrew from the intervention, study, or antiretroviral therapy. In transition readiness, we observed within-person improvements related to personal health (+1.9 points, p<0.001), healthcare usage (+2.4 points, p<0.001), knowledge (+3.3 points, p=0.001), and behavior (+3 points, p=0.003) at the end of the intervention, relative to baseline. We also observed strong evidence of improvements in medication adherence, social support, self-efficacy, and perceived stress, which were generally sustained three months after intervention cessation.ConclusionWe identified a community-based intervention that is feasible and potentially effective for bridging the transition to adult HIV care among a diverse group of ALWH in Peru. A larger-scale effectiveness evaluation, including biological endpoints, is warranted.