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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.

What is being tested?

The test is looking for evidence of infection by the herpes simplex virus, a common virus that may be sexually transmitted and causes small fever blisters (vesicles) on the mouth or genitals. There are two types of the herpes virus; HSV-1 and HSV-2. HSV-1 usually causes cold sores and both HSV-1 and HSV-2 can cause genital herpes.

The test for herpes infection is a swab of a lesion. A person who has noticed lesions in their genital area should be tested by a swab. In modern pathology laboratories in Australia these swabs will be tested by polymerase chain reaction (PCR).

How is it used?

The swab is used to detect the presence of the herpes simplex virus in a person with symptomatic herpes infection.

When is it requested?

Any sore in the genital area can be a symptom of a serious disease and should be tested.

What does the result mean?

A positive swab indicates active herpes (HSV-1 or HSV-2).

Is there anything else I should know?

Herpes is a lifelong infection. A person who has been infected with genital herpes may shed the virus without lesions and infect others.

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

Common questions

  • How is herpes transmitted?

The herpes simplex virus is transmitted through direct contact, which can include kissing; vaginal, oral, or anal sex; or other skin-to-skin contact. Genital herpes is most easily contracted by having sex with someone who has a vesicle, 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.

  • What are the symptoms of genital herpes?

The symptoms of genital herpes vary greatly. When first infected a person may experience obvious and painful lesions at the site of infection. These lesions appear within two weeks (typically in five to seven days) after the virus is transmitted and usually heal within two to four weeks. The vesicles can appear in the vaginal area, on the penis, around the anus, or on the buttocks or thighs. This primary episode can include a second outbreak of lesions in another area, usually nearby and flu-like symptoms of fever and swollen glands. Other symptoms of genital herpes infection include painful urination and urethral discharge, vaginal discharge or bleeding and discomfort from the rectum and anus. In some cases symptoms are mild and may be mistaken for something else, such as insect bites or another type of rash.

After the first episode, the virus goes into an inactive state. It may cause outbreaks from time to time. The outbreaks, which last about a week, can be blisters or open sores that crust over and then disappear, or other symptoms of herpes but milder than in an initial episode. They may be preceded by symptoms of tingling or stinging in the affected area. Recurrent episodes of rash caused by the same virus are usually much less severe than the first outbreak. Sometimes, the virus can become active and infectious with no noticeable sores. The virus never goes away, and the frequency and severity of recurrent episodes varies greatly among individuals.

  • How is herpes infection treated?

Treatments are available for all forms of herpes. For genital herpes valacyclovir given orally is the most common treatment. Topical therapies are available for cold sores. Eye infections may be treated with oral or topical therapies. In herpes infections in immunosuppressed persons, or babies, or of the central nervous system intravenous aciclovir is used.

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.

All anti-herpes medications work by inhibiting viral replication by interfering with the copying of viral DNA which stops the virus reproducing.

  • How common is it?

Genital herpes infections are the most common cause of genital ulcers throughout the world. Genital herpes is not a reportable disease in Australia and therefore the rates are not accurately known. Below is a graph showing the estimated numbers of people in each age group affected by genital herpes. However, up to 60% of individuals with genital herpes do not know they are infected because their symptoms are mild or absent. Infection with HSV-2 (the usual cause of genital herpes) is common; approximately 1 in 8 Australians aged 25 years and over have the virus (1 in 6 women and 1 in 12 men).

  • How can herpes be prevented?

Herpes is a highly infectious condition and the factors that determine the risk of transmission have not been entirely elucidated. Most people contract genital herpes from an individual that did not know they were infected. Condom use reduces the risk of herpes transmission.

When a person knows they are infected they can reduce the risk of passing genital herpes to another by refraining from sexual intercourse during outbreaks, by using antiviral medication, by telling their sexual partners of their infection and by using condoms. However, even using these methods the virus can be transmitted and symptoms may develop.

There is no vaccine available for the herpes virus.

  • How can I get herpes if I never had contact with someone who had lesions?

Many people with evidence of HSV infection never recognise any symptoms. People who do not know they are infected with herpes are an important source of spread of the virus.

  • What is the difference between HSV-1 and HSV-2? Can I get HSV-1 on my genitals? Can I get infected with HSV-1 if I already have HSV-2 (or vice versa)?

The herpes simplex virus comes in two types, HSV-1 and HSV-2. These viruses have preferred sites of infection. HSV-1 predominantly affects the lips and mouth whereas HSV-2 has adapted to infect the genital region.

However, as exposure to HSV-1 in childhood is becoming less common, HSV-1 is starting to replace HSV-2 as the predominant cause of genital herpes. In the United States HSV-1 is now a more common cause of genital herpes than HSV-2, and it is likely that this is also the case in Australia. HSV-1 infection of the genitalia is indistinguishable from HSV-2 infection, however recurrences occur less commonly with genetal HSV-1 infection, especially if the person already has HSV-1 infection of the lips/mouth. In contrast HSV-2 rarely affects the oral cavity.

  • I already have herpes. Can I catch it again?

Infection with another type of herpes (HSV-1 or HSV-2) is possible. A swab of the lesions can detect which type of herpes (HSV-1 or HSV-2) has caused them. In addition there are a number of different strains of both HSV-1 and HSV-2. It is also possible to become infected with a new strain of virus even if already infected (i.e. a different HSV-2). There is no way to easily determine if this has happened. To the individual it would appear either as a mild primary infection (if they were previously asymptomatic), a worse than normal recurrence (if they were previously symptomatic) or go unnoticed.

  • I have been diagnosed with herpes; will I give it to my partner? (Or my partner has herpes; will I get it?)

Herpes can be transmitted to your partner, although the overall risk is not high per episode of sex. The chance of transmission depends on the sex of your partner, condom use, the frequency of sex acts, medication use and avoidance of sex when lesions are present. On average in monogamous, heterosexual couples the rate of transmission is 8.9/10,000 sex acts for females and 1.6/10,000 sex acts for males.

  • I have cold sores. Can I give my partner genital herpes?

It is possible to get genital herpes from oral sex with a person who suffers from cold sores (oral HSV-1).

  • I am in a monogamous relationship and my partner has a herpes rash (or I have developed a herpes rash). Does this mean they have been unfaithful? Can I get herpes in areas other than my face and genitals?

Herpes infections can occur at sites other than the mouth and genitals. Usually these sites include those near to a primary site of infection and represent local spread by itching and touching. Occasionally there is spread to a distal site (such as the lips from a genital infection, especially with HSV-1). In cases like this it is most likely the infection is spread by touching with the hands but it may also represent spread via the blood stream. In a very few individuals, such as infants or people with impaired immune systems herpes can spread to affect multiple organs.

Primary herpes infections and recurrences can occur at other sites when skin (especially broken skin) is exposed to the virus. Herpes of the finger (especially of the wick of the nail) is called “Herpes Whitlow”. In wrestlers herpes of the body is called “Herpes Gladatorium”. These types of herpes are potentially infectious.

A potentially serious condition can occur when the herpes virus causes a primary infection of, or recurs in, the eye. This can lead to blindness and requires prompt attention by an eye doctor.

In rare cases herpes may involve the central nervous system. This can occur when herpes invades the nerves as part of a primary infection, or when it re-activates in the central nervous system. Usually, HSV-1 is implicated but HSV-2 is also capable of causing this type of infection.

  • Can herpes affect my baby?

Neonatal herpes is uncommon, affecting around 1 in 5,000 deliveries per year. Neonatal herpes infection is a serious condition that may have bad outcomes. However, it is becoming recognised that there is a spectrum of neonatal herpes and not all infections are severe.

Neonatal herpes is much more likely to occur if a mother develops her first episode of herpes during the third trimester. The infection can be passed to the newborn in the uterus, during birth or after the birth, but the most common situation is the baby acquires the infection during the delivery. In most cases when the infection has occurred before pregnancy, the mother’s antibodies will be passed on to the newborn and protect the newborn from serious infection.

A caesarean section may be done in some circumstances to reduce the risk of transmission. If a baby has been exposed to HSV during delivery it may require extra tests and/or treatment. Treatment can reduce the risks of neonatal HSV infection. The management of herpes infection during pregnancy should always be discussed with your doctor.

At present, routine testing of pregnant women without symptoms or their partners to reduce the risk of transmission to the infant is not recommended.

  • What are the consequences of herpes infection?

Herpes is a mild infection and many people experience few or no symptoms. When symptoms do 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. 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 (babies and people who have suppressed immune systems) with rare exceptions.

Most of the negative impact from herpes occurs because of fear of transmission of the virus, and fear of rejection by sexual partners or prospective sexual partners. Support is available for dealing with these situations and links are available at the end of this article. If more support is necessary, you should contact your GP or sexual health clinic.

  • I don’t have any symptoms of herpes - can I have a blood test to see if I have the disease?

A blood test (serology) can be performed to determine if someone has been exposed to HSV-1 or HSV-2, however this test is not recommended in the routine clinical setting. At present it is most useful in academic studies of herpes virus infections in the population.

  • I have had serology done, what do my results mean?

Herpes is a common virus in the community that causes latent infections. The interpretation of serology results is difficult and often frustrating for the patient. Serological testing is not recommended in routine clinical practice.

Last Updated: Thursday, 1st June 2023

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