Unexpected HIV Infections in Young Women in South Africa

Abstract

Unexpected HIV infections (not from sex, mother-to-child, or injection drug use) are common in Africa’s generalized epidemics. A 2011-2015 randomized controlled trial of cash transfers conditioned on high school attendance to reduce HIV incidence in young women in South Africa had no impact on HIV incidence but could nevertheless lead to more effective HIV prevention messages and programs. The study team has provided enough information on women’s self-reported sexual behaviour to estimate sex accounts for only a small minority of their HIV infections. At baseline 7.5% of 2,533 women aged 13-20 years reported unprotected sex in the previous three months. During 1-3 years of follow-up, women reported unprotected sex in the previous three months at 9% of annual visits. From published accounts of women’s self-reported sexual behaviour, with some (intended high) estimates to fill in for collected but unreported data, we estimate sex accounts for 7.6 (4.0%) of 188 HIV infections recognized during the trial, including 2.2 (2.7%) of 81 prevalent infections at baseline and 5.4 (5.0%) of 107 incident infections during follow-up. This conclusion challenges researchers to improve their efforts to find the sources of women’s infections, including tracing and testing partners and asking about blood exposures. This conclusion also challenges the Government of South Africa to investigate unexpected infections to find and stop their sources.