Background:

Herpes simplex virus type 2 (HSV-2) is an incurable STI associated with increased risk of acquiring and transmitting HIV. HSV-2 prevalence is extremely high in sub-Saharan Africa, but population-level estimates of HSV-2 incidence are sparse. We quantified HSV-2 prevalence, risk-factors for infection, and age-patterns of incidence in south-central Uganda.
Methods:

We measured HSV-2 prevalence from cross-sectional serological data among men and women aged 18-49 in two communities (fishing/inland). We identified risk-factors for seropositivity, and inferred age-patterns of HSV-2 with a Bayesian catalytic model.
Results:

HSV-2 prevalence was 53.6% (n = 975/1819, 95%CI 51.3%-55.9%). Prevalence increased with age, was higher in the fishing community, and among women, reaching 93.6% (95%CrI 90.2%-96.6%) by age 49. Factors associated with HSV-2 seropositivity included more lifetime sexual partners, HIV positive status, and lower education. HSV-2 incidence increased steeply in late adolescence, peaking at age 18 for women and 19-20 for men. HIV prevalence was up to ten-fold higher in HSV-2-positive individuals.
Conclusions:

HSV-2 prevalence and incidence were extremely high, with most infections occurring in late adolescence. Interventions against HSV-2, such as future vaccines or therapeutics, must reach young target populations. Remarkably higher HIV prevalence among HSV-2-positive individuals underscores this population as a priority for HIV prevention.