Epidemiology of herpes simplex virus type 2 in Asia: A systematic review, meta-analysis, and meta-regression.

backgroundHerpes simplex virus type 2 (HSV-2) infection is a prevalent sexually transmitted infection worldwide. This systematic review was conducted to characterize HSV-2 epidemiology in Asia, including the World Health Organization regions of Southeast Asia and the Western Pacific.

methodsCochrane and PRISMA guidelines were followed to systematically review and report findings. Pooled mean seroprevalence and proportions of HSV-2 isolated in genital ulcer disease (GUD) and in genital herpes were calculated using random-effects meta-analyses. Meta-regressions were also conducted. Quality assessment was performed.

findingsHSV-2 measures extracted from 173 publications included 15 seroconversion rates, 11 seroincidence rates, 272 overall seroprevalence measures (678 stratified), 14 proportions of HSV-2 isolation in GUD (15 stratified), and 27 proportions of HSV-2 isolation in genital herpes (36 stratified). Pooled mean seroprevalence was 12.1% (95% confidence interval (CI): 11.0-13.2%) among general populations, 23.6% (95% CI: 20.9-26.3%) among men who have sex with men and transgender people, 46.0% (95% CI: 39.2-52.9%) among HIV-positive individuals and individuals in HIV-discordant couples, and 62.2% (95% CI: 58.9-65.6%) among female sex workers. Among general populations, pooled mean seroprevalence increased gradually from 4.7% (95% CI: 3.3-6.3%) in <20-year-old individuals to 26.6% (95% CI: 19.2-34.7%) in >60-year-old individuals. Compared to women and across all populations, men had 0.60-fold (95% CI: 54.0-67.0) lower seroprevalence, that is women had 70% higher seroprevalence. Seroprevalence declined by 0.98-fold (95% CI: 0.97-0.99) per year, that is a 2% decline per year in the last three decades. Pooled mean proportions of HSV-2 isolation in GUD and in genital herpes were 48.2% (95% CI: 34.9-61.6%) and 75.9% (95% CI: 68.3-82.8%), respectively.

interpretationOver 1 in 10 individuals is infected with HSV-2, but seroprevalence is declining. HSV-2 accounts for half of GUD cases and three-quarters of genital herpes cases. These findings support the need for an HSV-2 vaccine and universal access to sexual and reproductive health services.

fundingThis work was supported by the Qatar National Research Fund [NPRP 9-040-3-008] and by pilot funding from the Biomedical Research Program at Weill Cornell Medicine in Qatar.