Incidence of Herpes Simplex Virus Type 2 Infections in Africa: A Systematic Review

A systematic review of studies conducted in Africa found high herpes simplex virus (HSV)-2 acquisition rates in both general and high-risk cohorts; thereby identifying an efficient setting for preventative HSV-2 vaccine trials.
The burden of HSV type 2 varies substantially by region, with the highest incidence and prevalence in sub-Saharan Africa. We undertook a systematic review to identify studies reporting prospective data on incidence rates in men and women in Africa. Of 18 eligible studies, 7 were conducted in high-risk populations. Among women, incidence rates appeared to be higher in those with high-risk sexual behavior, with rates ranging from 3 to 23 per 100 person-years. In contrast, incidence rates in men appeared to be lower, ranging from 1 to 12 per 100 person-years. Risk factors for HSV-2 in women included prevalent human immunodeficiency virus (HIV) infection, younger age at sexual initiation, and sexual activity. Among men, condom use and circumcision had a protective effect, whereas prevalent HIV increased the risk of HSV-2 acquisition. This review draws attention to the high HSV-2 acquisition rates reported in Africa, thereby identifying an efficient setting for preventative HSV-2 vaccine trials.