Predictors of secondary HIV transmission risk in a cohort of adolescents living with HIV in South Africa

Abstract

Objective: Preventing secondary HIV transmission from adolescents and young people living with HIV (AYPLHIV) to their partners and children is critical to interrupting the HIV infection cycle in sub-Saharan Africa. We investigated predictors of secondary HIV transmission risk (past-year sexual risk combined with past-year viremia) among AYPLHIV in South Africa. Design: A prospective cohort of AYLPHIV in South Africa recruited n ¼ 1046 participants in 2014 – 2015, 93.6% of whom were followed up in 2016 – 2017 (1.5% mortality). Questionnaires used validated scales where available and biomarkers were extracted from n ¼ 67 health facilities. Methods: Multivariate logistic regressions tested baseline factors associated with secondary HIV transmission risk, controlling for covariates, with marginal effect modelling combinations. Results: About 14.2% of AYPLHIV reported high secondary HIV transmission risk. High-risk AYPLHIV were more likely to be sexually infected [adjusted odds ratio (aOR) 2.79, 95% confidence interval (95% CI) 1.66 – 4.68, P < 0.001], and report hunger (aOR 1.93, 95% CI 1.18 – 3.14, P ¼ 0.008) and substance use (aOR 2.19, 95% CI 1.19 – 4.02, P ¼ 0.012). They were more likely to be in power-inequitable relationships (aOR 1.77, 95% CI 1.08 – 2.92, P ¼ 0.025) and be parents (aOR 4.30, 95% CI 2.16 – 8.57, P < 0.001). Adolescents reporting none of these factors had a 4% probability of secondary transmission risk, rising to 89% probability with all five identified factors. Older age and early sexual debut were also strongly associated with a higher risk of secondary HIV transmission. Conclusion: It is essential to identify and support AYPLHIV at a high risk of secondary transmission. Screening for factors such as mode of infection and parenthood during routine healthcare visits could help identify and provide resources to the most at-risk adolescents.