A viral infection that causes painful blisters on and around the genitals that can recur
- Can affect sexually active people of any age
- Unprotected sex with multiple partners is a risk factor
- Gender and genetics are not significant factors
Genital herpes is caused by the herpes simplex virus, of which there are two forms, known as type 1 (HSV-1) and type 2 (HSV-2). Genital herpes is usually due to type 2; type 1 mainly causes blisters around the mouth (see Cold sore). However, HSV-1 can be transmitted from the mouth to the genitals during oral sex, producing genital herpes. In the UK, there were about 29,000 new cases of genital herpes in 2008.
The disease can recur, especially in the first few years after the initial attack. In women, it tends to recur 5–12 days before a period and to clear up in a few days. Subsequent attacks are milder, but still infectious. A pregnant woman with genital herpes should inform her midwife of the fact because, very rarely, the infection causes serious illness in a baby exposed to it during birth (see Congenital infections).
What are the symptoms?
The first attack of genital herpes is usually the most severe and occurs within about 5 days of contact with an infected person. The symptoms may include:
Painful, fluid-filled blisters on the genitals. Blisters may occur on the thighs and buttocks and, rarely, in the mouth or rectum due to oral or anal sex.
Tingling, burning, soreness, and redness of the affected area.
Enlarged and painful lymph nodes in the groin.
Pain on passing urine.
Headache, fever, and muscle aches.
In women, vaginal discharge.
After 10–21 days the symptoms usually disappear. There may be further milder attacks, often affecting the same areas.
What might be done?
If you suspect genital herpes in yourself or your partner go to a clinic specializing in STIs or consult your doctor. A diagnosis will probably be made from your symptoms and a physical examination. Swabs of the blisters may be taken to test for the virus. You may also have tests for other STIs. Partners need to attend for a checkup even if they have no obvious symptoms.
Your doctor may prescribe aciclovir or another antiviral drug during an attack. If aciclovir is taken early, it usually reduces the severity of symptoms but it does not rid the body of the virus.
What is the prognosis?
About 2 in 10 infected people have only one attack. However, the virus remains in the body, and some people have recurrent attacks a few times a year for several years. Symptoms are usually less severe in subsequent attacks and the time between attacks increases.
Can it be prevented?
The risk of contracting genital herpes can be reduced by practising safe sex (see Preventing STIs). However, a condom may not always provide total protection since areas of skin around the genitals may have blisters or be less obviously infected. The virus can be passed on even if no blisters are present. If you have an attack, avoid sex until the symptoms have gone.
If you have repeated attacks, your doctor may prescribe preventive treatment with an antiviral drug to reduce the risk of a recurrence. Treatment is rarely needed for more than a year.
A pregnant woman who has a genital herpes attack close to delivery may need a caesarean section to prevent the infection passing to the baby.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
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