Summary

Herpes is a common virus that causes blisters and sores. There are two types: HSV-1 which predominantly causes cold sores around the lips and mouth and HSV-2 which has adapted to infect the genital region. Both HSV-1 and HSV-2 can cause genital herpes resulting in blisters around the vagina, on the penis, around the anus, or on the buttocks or thighs.

Testing is carried out on a swab of the affected area. A positive swab confirms you have the virus and your treatment will depend on the location of the blisters and sores. The treatment aims to reduce the symptoms and does not get rid of the virus. Once infected the herpes simplex virus stays in your body for life and it can never be fully eradicated.

Why get tested?

Throughout the world, genital herpes infections are the most common cause of genital ulcers. Genital herpes is not a reportable disease in Australia and so the rates are not accurately known. However, it is estimated that up to 60 per cent of people with genital herpes do not know they are infected because they either don't have any symptoms or else their symptoms are mild.  

The herpes simplex virus is transmitted through direct contact, which include all types of skin-to-skin contact including kissing, vaginal, oral, or anal sex. Genital herpes is most easily contracted by having sex with someone who has visible symptoms such as a blister or sore, but it can be transmitted even if there are no sores or other symptoms. People most often catch it by having sex with someone who doesn't know they are infected.

Herpes is generally a mild infection, and many people experience few or no symptoms. When symptoms develop, they are usually no more severe than a rash. At the time of the first infection, it is not uncommon to experience a few days of fever, headache, or tiredness as well as local symptoms. In more severe cases there may be obvious and painful blisters and sores at the site of infection. These appear within two weeks - typically in five to seven days- after the virus is transmitted and usually heal within two to four weeks.

After the first time someone is infected, the virus goes into an inactive state. It may cause outbreaks from time to time without further exposure. These last for about a week and can be blisters or open sores that crust over and then disappear.  They may be preceded by symptoms of tingling or stinging in the affected area. Recurrent episodes are usually much less severe than the first outbreak. The frequency and severity of recurrent episodes varies greatly from person to person.

Serious complications from herpes are unusual. Rarely, herpes can cause serious infection in the blood and internal organs. This type of severe infection is called disseminated herpes and usually only occurs in vulnerable people such as babies and people who have suppressed immune systems.

To perform the test a swab or scraping is taken from a blister or sore in the mouth or genital area. The sample is sent to the laboratory where the virus is detected using a polymerase chain reaction (PCR) test. A positive swab indicates active herpes, either HSV-1 or HSV-2. 

Having the test

Sample

A swab or scraping from a blister or sore in the infected area. Blood or CSF may be collected in cases of disseminated infection.

Any preparation?

None required.

Your results

If your swab is positive for either or both of the herpes viruses your doctor will recommend one of several treatments.

For genital herpes, the most common treatment is valacyclovir in tablet form. Cold sores are usually treated with topical therapies. Eye infections may be treated with drugs or topical therapies. For immunosuppressed people or babies the therapy of choice is often intravenous acyclovir.

All anti-herpes medications work by interfering with the copying of viral DNA which stops the virus reproducing. Treatments do not cure the herpes infection but they can shorten the duration of and reduce the severity of outbreaks. Long-term suppressive oral therapy can reduce the frequency of outbreaks.

Questions to ask your doctor

The choice of tests your doctor makes will be based on your medical history and symptoms.   It is important that you tell themeverything you think might help. 

You play a central role in making sure your test results are accurate. Do everything you can to make sure the information you provide is correct and follow instructions closely. 

Talk to your doctor about any medications you are taking. Find out if you need to fast or stop any particular foods or supplements. These may affect your results. Ask:

• Why does this test need to be done?
• Do I need to prepare (such as fast or avoid medications) for the sample collection?
• Will an abnormal result mean I need further tests?
• How could it change the course of my care?
• What will happen next, after the test?

Any more to know?

Herpes is highly infectious and the factors that determine the risk of transmission are not entirely clear. Most people contract genital herpes from someone who did not know they were infected. Condom use reduces the risk of herpes transmission.

When someone knows they are infected they can reduce the risk of passing on genital herpes by not having sex during outbreaks, by using antiviral medication, by telling their partners of their infection and by using condoms. However, even when using these methods the virus can be transmitted and symptoms can develop.

There is no vaccine available for the herpes virus.

Herpes can make people more susceptible to HIV infection and can make people who have HIV more infectious to others.

More information

Get further trustworthy health information and advice from healthdirect.