Herpes simplex viruses types 1 and 2 are very widespread throughout the world and responsible for recurrent vesicular or ulcerative lesions. Type 1 (HSV-1) is transmitted primarily through oral contact and causes lesions in or around the mouth. It can also be responsible for genital herpes. Type 2 (HSV-2) infection is sexually transmitted and is the main cause of recurrent genital ulcers.
Genital herpes is associated with pain, but it also has negative repercussions on sexual relations, on quality of life, as well as psychologically. In addition, HSV-2 is suspected of facilitating the acquisition and transmission of HIV.
A recent study updates estimates of the incidence and prevalence of genital HSV infections worldwide during 2020. The authors based themselves on systematic reviews, meta-analyses and meta-regressions published in over the last few years.
Despite prevention, infections remain common
The data confirms the scale of the disease, since in 2020 around 26 million people worldwide, aged 15 to 49, were infected with HSV-2 for the first time, 520 million people live with this virus and 188 million of them have had at least one episode of genital herpes caused by it.
Additionally, in the same year, 17 million people aged 15 to 49 were infected with HSV-1 during sexual intercourse, 376 million were living with genital HSV-1 infection, and 17 million had at least 1 episode of genital herpes caused by HSV-1. The authors add that sexual transmission represents only a small portion of HSV-1 infections, since in total, nearly 4 billion people worldwide are infected (mainly in the oral form) by HSV-1 in 2020, with more than 120 million primary infections that year.
HSV-2 is responsible for the majority of genital infections. Virtually all HSV-2 infections are sexually transmitted and occur in the genital area. The majority of HSV-1 infections are not sexually acquired but are most often acquired in childhood. However, the number of sexually acquired HSV-1 infections in adolescence or adulthood is increasing. Recurrences are less frequent during genital HSV-1 infections compared to those due to HSV-2.
The global prevalence of HSV-2 is approximately the same in 2016 and in 2020, which, taking into account demographic changes, suggests that the prevalence of HSV-2 is slowly decreasing, a trend already reported in other works and which could be the the result of increased awareness of sexually transmitted infections and better access to care.
However, given the persistence of this high prevalence, it is clear that the available prevention methods, condoms and antivirals, are insufficient to control the transmission of the infection and have only a modest impact in reducing its incidence. . For the authors, prophylactic and therapeutic vaccines are the most relevant approach to control transmission and bend the curve of the disease and the economic burden of these infections.
