Genital Herpes: Reducing your risk

This information is not provided for the purpose of diagnosis or medical treatment and should not be considered a substitute for medical advice from a doctor.

Genital herpes is one of the most common sexually transmitted diseases (STDs) in the world. It is a viral infection that is spread by close contact with somebody who has been infected with the herpes simplex virus (HSV). Anyone who is sexually active can become infected with genital herpes. It is not life-threatening but unlike most other STDs, it is a lifelong condition.

This section of the website aims to show how you can help to protect yourself against the risk of being infected with genital herpes and also, how to reduce the risk of transmitting the virus to others.

What causes genital herpes?

Genital herpes is caused by infection with the herpes simplex virus (HSV). There are two strains of the virus: HSV-1 and HSV-2. HSV-1 is more commonly associated with facial herpes (cold sores), while genital herpes is usually caused by HSV-2. However, cross infection can occur: HSV-1 can be transmitted to the genital area through skin to skin contact (for example during oral sex) and less commonly, genital herpes can be transmitted to the face.

Once the HSV virus has entered the body, it travels along the nerve paths to take up residence in nerves close to the spine called ganglia, where it remains for the rest of a person's life. This is known as latency. Some people experience no further episodes of genital herpes but in others, the virus is reactived from time to time to cause a recurrence. When the virus is triggered into action, it makes its way back along the nerves towards the genital area and leads to a new outbreak of symptoms. Recurrences are usually shorter and symptoms are less severe than during the primary infection.

How is genital herpes transmitted?

Genital herpes is spread by direct contact, usually during sexual activity. The virus is more likely to be transmitted if sexual contact takes place during an active episode of herpes. Since some people experience no symptoms, or they are so mild as to go unnoticed, it is not always possible to know when you or your partner are having an active outbreak of genital herpes. Unfortunately, it is still possible to transmit the virus even in the absence of symptoms - this is known as asymptomatic shedding. The section genital herpes and sex includes more detailed information on the ways in which genital herpes can be transmitted.

Could I have genital herpes without knowing it?

Yes. Many people have no obvious symptoms and do not realise they have come into contact with the HSV virus. It is estimated that as many as 80% of people infected with HSV-2 are unaware that they have the virus.(2) These people are, however, still capable of transmitting the virus to others. The only way to know for certain whether you have been infected or not is to talk to your doctor about having a herpes test. Swabs and blood tests can be used to show whether you have been exposed to the virus, and in some cases, can determine whether you have been infected with HSV-1 or HSV-2. The section Diagnosis & Diagnostics on this website provides further information about the different tests available.

What can I do to minimise the risk of contracting herpes?

There are several ways in which you can minimise your exposure to HSV.

First, avoid any sexual contact when your partner is having an active outbreak of genital herpes, ie is experiencing symptoms such as sores or blisters. This includes the time from when your partner first notices any warning signs of an impending outbreak, such as a tingling or burning sensation in the genitals, until the sores have completely healed. Using latex condoms can help to reduce the risk of transmission at these times, but avoidance of sex during active outbreaks is the best measure as the virus can still be passed on by contact with areas of the skin not covered by the condom.

The use of latex condoms are recommended during all sexual contacts, even when no symptoms are present, as it is still possible to transmit the virus in the absence of symptoms (see asymptomatic shedding above). Protection again is not 100% as the virus may be shed from areas not covered by the condom.

Remember that many people with herpes do not have symptoms or do not recognise symptoms. Therefore, you may wish to get tested to see if you already have HSV antibodies. If you test positive for the same type of herpes your partner has, you may not need to take precautions.

You should be aware that if you are in a long-term relationship with somebody who has genital herpes, there is a chance that you will be infected as well, even if you are extremely careful.

If one partner in a couple has been infected with the genital herpes virus and the other has not, it may be appropriate for the partner with genital herpes to consider suppressive antiviral therapy (preventive treatment that is taken on a daily basis to reduce transmission and the number of outbreaks).

Can treatments help reduce transmission?

Recent research has shown that the use of suppressive antiviral therapy can substantially reduce the risk of passing genital herpes on to a partner. A major trial of valaciclovir, one of the commonly prescribed antivirals, shows that when it is prescribed as a once-daily suppressive therapy and in conjunction with safer sex practices, it can reduce the risk of transmission of symptomatic genital herpes (signs and symptoms of infection) by 75%.(1)

I have been diagnosed with genital herpes. How can I reduce the risk of transmitting the virus to other people?

Whether you are in a long-standing relationship or are considering embarking on a new one or a more casual encounter, it is responsible to tell your partner that you have genital herpes so that you can discuss the best ways of reducing the risk of transmission. The most important precautionary measure is to avoid sexual contact when you are having an active episode of herpes. Using latex condoms between episodes can provide some degree of protection but this is not 100%. Unfortunately, it is not always possible to be sure when you are having an active episode and you should be aware that it is still possible to pass on the infection even if you are experiencing no symptoms (this is known as asymptomatic shedding). For this reason, condoms should be used during all sexual episodes.

If you are in a longer-term relationship and your partner does not have genital herpes, you may wish to consider trying suppressive antiviral therapy, which can reduce the risk of passing genital herpes on to a partner. The section above includes further information on this.

Does having genital herpes expose me to any other risks?

Having been diagnosed with genital herpes, many people focus on the potential risk they pose to other people in terms of transmitting the herpes virus. However, it is equally important to consider the possible impact on your own health. Having genital herpes can make you more vulnerable to acquiring other sexually transmitted diseases. For example, there is evidence to suggest that people who have genital herpes are more likely to acquire HIV (human immunodeficiency virus) from an HIV-infected person during intimate contact, compared to those who do not have genital herpes. This is most likely to happen during sexual intercourse with an HIV-infected partner when they are experiencing an outbreak of herpes. Thus any discussions about reducing the risk of acquiring sexually transmitted diseases should be a two way process, covering ways of reducing the risk of transmission to your partner and also of protecting yourself against other infections.

References
1. Corey LC, Wald A, Patel R et al. Once-daily valacyclovir to reduce the risk of transmission of genital herpes. N Engl J Med 2004;350:11-20
2. Corey LC. The Current Trent in Genital Herpes. Progress in Prevention. Sex Transmitted Diseases 1994;21 (Suppl 2) : pS38-S44