Abstract
PURPOSE: Why do orphans have higher rates of HIV infection than nonorphaned peers? Research consistently assumes that orphans acquire HIV primarily through sexual behavior, but infections may instead be due to maternal transmission. Although these two pathways have very different implications for HIV programs and policies, their relative contribution has not been previously examined. In this research, we compare the contribution of maternal and sexual transmission to HIV infection among orphans in Africa. METHODS: We use Demographic and Health Survey data for 21,463 women and 18,359 men from 17 countries. We propose a conceptual framework linking orphanhood to HIV, and use mediation analysis and structural equation modeling to compare the potential contribution of maternal transmission (measured through direct pathways from orphanhood to HIV) and sexual transmission (measured through reports of risky sexual behavior) to orphan HIV infection. RESULTS: Our results suggest that maternal transmission is the predominant pathway of HIV infection among orphaned adolescents: there is strong evidence for a direct pathway from maternal (odds ratio [OR]: 2.45; 95% confidence interval [CI]: 1.72-3.51 for females and OR: 2.45; 95% CI: 1.53-3.90 for males) and double orphanhood (OR: 2.69; 95% CI: 1.97-3.66 and OR: 2.53; 95% CI: 1.68-3.82, respectively) to HIV; greater excess HIV risk in maternal versus paternal orphans. The contribution of sexual behavior is largely not significant. We do not observe correspondingly high orphan disparities in other sexually transmitted diseases. CONCLUSIONS: Maternal transmission is a more likely explanation than sexual transmission for heightened HIV infection among orphans. These results suggest that programs designed to address HIV infection among adolescents should focus on reducing maternal transmission and on identifying and testing undiagnosed HIV among orphans.