High HIV incidence in young women in Sub-Saharan Africa remains a key challenge to HIV epidemic control. HIV incidence rates in young women exceed those of men and older women, and the proportion of young HIV-positive women who know their status and are virally suppressed falls well short of the UNAIDS ‘90-90-90’ targets. This study examined the factors associated with seroconversion in young women in a hyperendemic area of South Africa.
We analysed prospective cohort data of HIV-negative women (15-24 years) from the HIV Incidence Provincial Surveillance System conducted in KwaZulu-Natal, South Africa. Participants (n=2,710) completed a questionnaire and provided blood samples for laboratory testing (pregnancy, HIV and other STIs) at enrolment and follow-up approximately 18 months later. The association between risk factors and HIV-seroconversion was assessed using Cox proportional hazards models.
The incidence rate of young women was 3.92 (95% confidence interval (CI): 3.27-4.69) per 100 women-years; 3.74 (95% CI: 2.87-4.86) and 4.13 (95% CI: 3.20-5.33) per 100 women-years for women aged 15-19 and 20-24 years respectively. At follow-up, median (interquartile range) viral load of seroconverters was 4,400 (280-50,000) copies/ml and 17% reported knowing their HIV-positive status. Risk of seroconversion in young women increased significantly with the number of lifetime partners reported at baseline. Among teenage girls (15-19), risk of seroconversion was positively associated with being an orphan (adjusted hazard ratio (aHR)=4.38, p=0.005) and having a baseline STI (aHR=2.37; p=0.016), and negatively associated with having family support (aHR=0.46, p=0.022) and having a circumcised partner (aHR=0.58, p=0.047). For women aged 20-24 years, failure to complete high-school (aHR=1.78; p=0.042) and inconsistent condom use (aHR=2.72; p=0.024) were associated with HIV acquisition.
This study suggests that structural factors contribute to the high HIV incidence rates observed in young women in this population. However, programs supporting sexual health, male circumcision and condom use remain effective ways to reduce risk. In addition to supporting such programs, it is imperative that HIV testing frequency of young women be increased so that infections can be diagnosed timeously, treatment can be provided and transmission risk reduced.