Estimates of the Prevalence and Incidence of Genital Herpes, United States, 2018.

BACKGROUND Although there are more recent estimate of genital herpes prevalence, incidence estimates in the United States (US) have not been updated since 2008. METHODS We estimated genital herpes prevalence and incidence for 2018 among adults aged 18-49 years. We estimated prevalence using 2015-2018 NHANES herpes simplex virus (HSV) type 2 (HSV-2) seroprevalence data among the non-institutionalized civilian population and extrapolated this prevalence to the full US population using 2018 American Community Survey data. We estimated incidence using 2011-2018 NHANES HSV-2 data as inputs to a simple mathematical model. We used Monte Carlo simulation to generate 10,000 input parameter sets for age and sex subpopulations and summarized our estimates by their median; uncertainty intervals for these estimates are characterized by their first (Q1) and third (Q3) quartiles. We conducted sensitivity analyses investigating the impact of HSV type 1 (HSV-1) infection on estimates of genital herpes burden. RESULTS In 2018, there were an estimated 18.6 (Q1=18.1, Q3=19.0) million prevalent and 572,000 (Q1=479,000, Q3=673,000) incident genital herpes infections among 18-49-year-olds. Women accounted for two-thirds of prevalent infections with an estimated 12.1 (Q1=11.9, Q3=12.5) million infections. Incidence was highest among 18-24-year-olds with an estimated 242,000 (Q1=210,000, Q3= 274,000) infections. Sensitivity analyses indicated that HSV-1 could be responsible for millions more prevalent genital herpes infections, and tens of thousands of additional incident genital herpes infections, depending on the percentage of HSV-1 infections that are genital. DISCUSSION Genital herpes is a common sexually transmitted disease in the United States. Future research to understand the burden of genital infections attributable to HSV-1 would refine estimates of genital herpes burden.