P320 Sexual behaviours and Herpes Simplex Virus Type-2 Incidence and Prevalence among adolescent girls and young women in KwaZulu-Natal, South Africa

Background Adolescent girls and young women (AGYW) in rural KwaZulu-Natal, South Africa are disproportionately affected by herpes simplex virus type 2 (HSV-2) and HIV. As HSV-2 infection enhances the acquisition and transmission of HIV and other STIs, broader STI control requires understanding of HSV-2 predictors. We therefore assessed how HSV-2 incidence and prevalence were associated with sexual behaviours among AGYW in this region. Methods We analysed data from a two-year (2017–2019) prospective cohort study among a random sample of 2184 AGYW aged 13–22 which was representative of the study population. Data were collected at baseline, 12 months and 24 months. We calculated HSV-2 prevalence at any study visit and incidence among those HSV-2 negative at baseline. We ran Poisson and logistic regressions to assess the association of sexual behaviours with both HSV-2 incidence and prevalence. Results HSV-2 prevalence was 26.2% among the study population, and was strongly associated with having sexual debut before the age of 16 (adjusted odds ratio (aOR) 1.52, 95% confidence interval (CI) 1.06–2.17) and having two or more sexual partners in the past 12 months (aOR 3.64, 95% CI 1.39–9.50). 307 of 1,433 baseline HSV-2 seronegative AGYW seroconverted during follow-up (incidence rate 16.5/100 person years at risk, 95% CI 14.7–18.4). Self-reported lower age of sexual debut, one or more sexual partners and inconsistent condom use were bivariately associated with HSV-2 incidence. None of these self-reported sexual behaviour measures remained associated with incident HSV-2 after adjusting for socio-demographic, social and biological variables. Conclusion The high HSV-2 rates among AGYW particularly those engaging in high-risk sexual behaviours underscores the need for HSV-2 control interventions to slow its spread and other STIs in KwaZulu-Natal. However, further research is required for more targeted interventions due to the lack of association between sexual behaviours and HSV-2 incidence.