Global Burden of HSV-1 Infection 'Huge'

Megan Brooks

October 28, 2015

Worldwide, more than 3.7 billion people aged younger than 50 years — or 67% of the population — are infected with herpes simplex virus type 1 (HSV-1), according to the World Health Organization's (WHO) first global estimates of HSV-1 infection.

HSV-1 and HSV-2 are both highly infectious and incurable. HSV-1 is primarily transmitted by oral–oral contact and in most cases causes cold sores around the mouth, while HSV-2 is largely sexually transmitted through skin-to-skin contact causing genital sores.

However, the new estimates, published online today in PLoS One, highlight that HSV-1 is also an "important" cause of genital herpes, WHO said in a news release.

They note that roughly 140 million people aged 15 to 49 years have genital HSV-1 infection, primarily in the Americas, Europe, and Western Pacific. "Fewer people in high-income countries are becoming infected with HSV-1 as children, likely due to better hygiene and living conditions, and instead are at risk of contracting it genitally through oral sex after they become sexually active," WHO said.

They estimate HSV-1 prevalence by region among those aged younger than 50 years in 2012 as follows:

  • Americas: 178 million women (49%), 142 million men (39%)

  • Africa: 350 million women (87%), 355 million men (87%)

  • Eastern Mediterranean: 188 million women (75%), 202 million men (75%)

  • Europe: 207 million women (69%), 187 million men (61%)

  • South-East Asia: 432 million women (59%), 458 million men (58%)

  • Western Pacific: 488 million women (74%), 521 million men (73%)

They estimate new HSV-1 infections among people aged 0 to 49 years in 2012 as follows:

  • Americas: 6 million women, 5 million men

  • Africa: 17 million women, 18 million men

  • Eastern Mediterranean: 6 million women, 7 million men

  • Europe: 5 million women, 5 million men

  • South-East Asia: 13 million women, 14 million men

  • Western Pacific: 11 million women, 12 million men

Earlier this year, WHO estimated that 417 million people aged 15 to 49 years have HSV-2 infection. "Taken together, the estimates reveal that over half a billion people between the ages of 15-49 years have genital infection caused by either HSV-1 or HSV-2," WHO said.

"Access to education and information on both types of herpes and sexually transmitted infections is critical to protect young people's health before they become sexually active," Marleen Temmerman, MD, PhD, director of WHO's Department of Reproductive Health and Research, said in the release.

"The new estimates highlight the crucial need for countries to improve data collection for both HSV types and sexually transmitted infections in general," Dr Temmerman added.

"Given the lack of a permanent and curative treatment for both HSV-1 and HSV-2, WHO and partners are working to accelerate development of HSV vaccines and topical microbicides, which will have a crucial role in preventing these infections in the future. Several candidate vaccines and microbicides are currently being studied," according to WHO.

The agency is working on the development of a global health sector strategy for sexually transmitted infections, including HSV-1 and HSV-2, to be finalized for consideration at the 69th World Health Assembly in 2016.

PLoS One. Published online October 28, 2015. Full text


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.