Global and regional trends in herpes simplex virus type 2 infection and genital ulcer disease

Herpes simplex virus type 2 (HSV-2) infection is a prevalent infection. This study characterizes historical and future trends in HSV-2 infection at global and regional levels. A dynamic model simulated HSV-2 transmission from 1980 to 2050 across global regions and was calibrated to prevalence data from systematic reviews. Globally, HSV-2 prevalence among individuals aged 15–49 years declined from 13.5% in 1980 to 13.0% in 2005, then increased to 13.6% in 2025 and is projected to reach 15.9% by 2050. Incidence rate declined from 8.2 per 1,000 person-years in 1980 to 7.8 in 2007, before rising to 8.1 in 2025 and 9.5 by 2050. Annual new infections increased from 15.0 million in 1980 to 27.7 million in 2025 and are projected to reach 37.6 million by 2050. The number of individuals experiencing genital ulcer disease increased from 95.0 million in 1980 to 179.0 million in 2025 and is projected to reach 250.7 million by 2050. After 25 years of decline following 1980, HSV-2 metrics are projected to continue increasing through 2050, highlighting the need for effective interventions.