Background/introduction Genital herpes, usually caused by infection with herpes simplex virus type 2 (HSV-2), can cause substantial morbidity in the form of painful genital ulcers in infected adults and adolescents, as well as significant psychosocial morbidity. Neonatal herpes, acquired during delivery from mothers with genital herpes, is rare but often fatal. Additionally, HSV-2 increases susceptibility to, and transmissibility of, HIV. The global burden of HSV-2 was last estimated for 2003.

Aim(s)/objectives To present new global HSV-2 estimates for 2012 for females and males aged 15–49 years.

Methods Literature review of HSV-2 prevalence studies world-wide since 2000, followed by fitting of a model with constant HSV-2 incidence by age to pooled HSV-2 prevalence values by WHO region, age and sex. Prevalence values were adjusted for test sensitivity and specificity.

Results In 2012, we estimate that 417 million people aged 15–49 years (range: 274–678 million) had existing HSV-2 infection world-wide: a global prevalence of 11.3%. Of those infected, 267 million were women. Also in 2012, we estimate that 19.2 million (range: 13.0–28.6 million) individuals aged 15–49 years were newly-infected with HSV-2: 0.5% of all individuals globally. Prevalence was highest in Africa (31.5%), followed by the Americas (14.4%). Burden of numbers infected was highest in Africa. However, despite lower prevalence, South-East Asia and Western Pacific regions also contributed large numbers to the global totals because of large population sizes.

Discussion/conclusion The global burden of HSV-2 infection is large, highlighting the critical need for development of vaccines, microbicides and other prevention strategies against HSV-2.