The World Health Organization (WHO) has updated its fact sheet on Herpes Simplex Virus (herpes).
This article will focus on Herpes Simplex Virus type 2 (HSV-2).
Those who wish to read about HSV-1, are requested to read the first article in this series:
Background Information:
Infection with the herpes simplex virus, commonly known as herpes, can be due to either herpes simplex virus type 1 (HSV-1) or herpes simplex virus type 2 (HSV-2).
HSV-1 is mainly transmitted by oral to oral contact to cause infection in or around the mouth (oral herpes). However, HSV-1 can also be transmitted to the genital area through oral-genital contact to cause genital herpes.
HSV-2 is almost exclusively sexually transmitted, causing infection in the genital or anal area (genital herpes).
Key Messages:
HSV-2 infection is widespread throughout the world and is almost exclusively sexually transmitted, causing genital herpes.
It is the main cause of genital herpes; infection is lifelong and incurable.
Magnitude of the Problem
Genital herpes caused by HSV-2 is a global issue, and an estimated 417 million people worldwide were living with the infection in 2012.
Prevalence of HSV-2 infection was estimated to be highest in Africa (31.5%), followed by the Americas (14.4%). It was also shown to increase with age, though the highest numbers of people newly-infected were adolescents.
More women are infected with HSV-2 than men; in 2012 it was estimated that 267 million women and 150 million men were living with the infection. This is because sexual transmission of HSV is more efficient from men to women than from women to men.
Signs and symptoms
Genital herpes infections often have no symptoms, or mild symptoms that go unrecognised.
Most infected people are unaware that they have the infection.
Typically, about 10-20% of people with HSV-2 infection report a prior diagnosis of genital herpes.
When symptoms do occur, genital herpes is characterised by one or more genital or anal blisters or open sores called ulcers. In addition to genital ulcers, symptoms of new genital herpes infections often include
- fever,
- body aches, and
- swollen lymph nodes.
After an initial genital herpes infection with HSV-2, recurrent symptoms are common but often less severe than the first outbreak. The frequency of outbreaks tends to decrease over time.
People infected with HSV-2 may experience sensations of mild tingling or shooting pain in the legs, hips, and buttocks before the occurrence of genital ulcers.
Transmission
HSV-2 is mainly transmitted during sex, through contact with
- genital surfaces,
- skin,
- sores or fluids of someone infected with the virus.
HSV-2 can be transmitted from skin in the genital or anal area that looks normal and is often transmitted in the absence of symptoms.
In rare circumstances, HSV-2 infection can be transmitted from a mother to her infant during delivery.
Possible complications
- HSV-2 and HIV (HSV-2 and HIV have been shown to influence each other. HSV-2 infection increases the risk of acquiring a new HIV infection by approximately three-fold. In addition, people with both HIV and HSV-2 infection are more likely to spread HIV to others. HSV-2 is amongst the most common infections in people living with HIV, occurring in 60-90% of HIV-infected persons.)
- Neonatal herpes (when an infant is exposed to HSV in the mother’s genital tract during delivery)
- Psychosocial impact
Treatment
Antiviral medications (such as acyclovir, famciclovir, and valacyclovir) can help to reduce the severity and frequency of symptoms, but cannot cure the infection.
Prevention
Individuals with symptoms of genital herpes should abstain from sexual activity whilst experiencing any of the symptoms.
HSV-2 is most contagious during an outbreak of sores, but can also be transmitted when no symptoms are felt or visible.
The consistent and correct use of condoms can help to prevent the spread of genital herpes.
Pregnant women with symptoms of genital herpes should inform their health care providers. Preventing acquisition of a new genital herpes infection is particularly important for women in late pregnancy, as this is when the risk for neonatal herpes is greatest.
Additional research is underway to develop more effective prevention methods against HSV infection, such as vaccines or topical microbicides (compounds which can be applied inside the vagina or rectum to protect against sexually transmitted infections).
Useful Links:
Link to the updated fact sheet:
http://www.who.int/mediacentre/factsheets/fs400/en/
Link to WHO Guidelines for the treatment of Genital Herpes Simplex Virus (English) [PDF] (2016):
http://apps.who.int/iris/bitstream/10665/250693/1/9789241549875-eng.pdf?ua=1
Link to WHO brochure on sexually transmitted infections (English) [PDF]:
http://apps.who.int/iris/bitstream/10665/82207/1/WHO_RHR_13.02_eng.pdf?ua=1
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