Laboratory Markers and Characteristics of New HIV Infections Among Adolescents in Zambia
Background We aimed to explore HIV RNA (ribonucleic acid) virologic levels greater than 1,000 copies/millilitre (ml), among HIV-positive adolescents aged 15–24 years, establish the spread of CD4 T- cell counts and inspect characteristics of adolescents presenting with new HIV infections, including co-infections with Hepatitis B virus and syphilis. Methods We analysed data from the Zambia Population-based HIV Impact Assessment 2016 survey. Two-stage stratified cluster probability sample design
... ity sample design was used to select the target population. Our study truncated the population to focus on the age-group 15–24 whose biomarker tests and household information were complete. Our primary outcome measure was "New HIV-positive Infections among 15-24-year-olds" defined as HIV-positive biomarker samples presenting with HIV RNA ≥ 1,000 copies/ml without detectable ARVs. We tested associations between new HIV infections and clinical characteristics using negative binomial models adjusting for age, sex, education, marital-status, residence among several covariates. Results Overall, 2·3% ([166/7320], 95% CI: 1·9–2·6) adolescents aged 15–24 years were diagnosed with new HIV infections, with greater proportions among females (3·3% [139/4,165], 95% CI: 2·8–3·9) than males (0·86% [27/3,155], 95% CI: 0·6–1·2). Almost half (47·6%) of seroconversions had HIV RNA ≥ 50,000 copies/ml and an average CD4 + T-cell count of 479 cells/mm 3. HBV– positive adolescents (IRR 8·6, 95% CI: 2·9–24·9, P < 0·001, model 2) were at increased risk of new infections unlike those testing positive for syphilis antibodies (IRR 1·22, 95% CI: 0·2–8·3, P < 0·84). Adjusting for confounders revealed that being married or cohabiting, testing positive for HBV, being a rural resident and attaining higher than secondary education emerged as strongest correlates of new infections. Conclusion High baseline levels of viral load and low CD4 + T-cell count in recent HIV infections among adolescents indicate weak immune repertoire at first diagnosis, increasing the risk of contagion. As the epidemic continues to spread within the adolescent population, HIV-infection will become more complex and greater proportions of adolescents will likely be infected by regular partners. This suggests growing need for interventions targeted at stable partnerships and intensified public health campaigns specific for adolescents.