Genital herpes is a very common sexually transmitted infection (STI) and seems to cause more anxiety among patients than almost any other STI. Yet, generally, the physical suffering caused by recurring herpes is relatively minor, except for those who are immunosuppressed, in whom lesions may be severe, very painful and long-lasting. Genital herpes may cause significant psychosocial distress and interfere in a young person’s sex life to the extent that some people will choose to avoid entering into a relationship for fear of transmitting their infection. When a patient raises the issue of herpes it is always wise, in my experience, to take a deep breath and prepare for the possibility of a lengthy consultation.

In the past it was generally said that herpes simplex virus (HSV) type 1 occurs above the waist and HSV-2 below the waist. In recent years, however, HSV-1 is increasingly being recognised as causing genital infections. A Melbourne laboratory study from some years ago showed that some 70 per cent of genital infections in young adults were caused by type 1 virus¹, transmitted to the genitals by the increasingly popular pastime of oral-genital sexual contact. With this in mind, it is very important when someone presents with a history of genital herpes to ascertain the type of virus involved. This has major implications for the natural history of the infection and for treatment options. HSV-1, although more common nowadays among young people, is less likely to recur frequently and is less likely to be transmitted to a sexual partner than is type 2 virus.

This young woman who has come to see you is certainly not alone in her herpes infection, although she may feel at times as though she is the only one afflicted! The seroprevalence of HSV-2 in the adult Australian population is 12 per cent², and this is borne out by several studies of antenatal attendees that put the seroprevalence at 12–14 per cent. Many people with genital herpes, however, have only very mild symptoms or no symptoms at all and, as such, are never diagnosed. HSV-2 can be transmitted sexually at any time – it is not necessary for lesions to be present for virus to be transmitted – and diagnosis is the first step to reduce transmission.

Diagnosis

Hopefully, your patient will have knowledge of the viral type and this can be confirmed with the doctor or laboratory that diagnosed her infection. Always beware the patient who says she has genital herpes that has never been confirmed – these ‘herpes infections’ sometimes turn out to be due to another condition altogether, such as vulval dermatitis, thrush or even lichen sclerosis. Genital herpes lesions can only be reliably diagnosed when they are present via the use of a swab for PCR testing. Viral culture is no longer performed (except in some research laboratories) and PCR for HSV has excellent sensitivity and specificity. If no lesion is present at the consultation and no other evidence as to the diagnosis is available, then asking the patient to swab her own lesions when they occur and drop the specimen into the local pathology collection centre is a good alternative.

The place of serological blood testing for herpes simplex is controversial and in general it is not recommended. Type-specific herpes serology is available via pathology laboratories but there can be problems with the accuracy of such tests, particularly with their sensitivity (they can give false-negative results). Therefore, serology is not recommended for general screening, though it may have its place in those patients with unusual symptoms, or if the patient is in between episodes or in first episode genital herpes to try to determine whether or not the episode is a true primary or a recurrence (antibodies to HSV may take several weeks to develop). In addition, serological testing may be helpful in the pregnant woman who has no history of genital herpes, but whose partner has genital herpes.

Treatment options

Once the diagnosis is confirmed, the issue of treatment arises. The options are:

1. No drug treatment – may suit those women who are not in a relationship (or whose partner also has HSV-2), and whose recurrences are uncommon and/or not troublesome.
2. Suppressive antiviral therapy – daily medication will reduce the frequency, severity and length of outbreaks considerably and also reduces the risk of transmission. Valaciclovir (‘Valtrex’) was shown in a study to halve the risk of transmission in heterosexual monogamous couples where the infected partner took daily suppressive treatment.³ It is likely that famciclovir (‘Famvir’) would produce the same benefit.
3. Intermittent antiviral therapy – this option may suit women who have mild, occasional herpes episodes and for whom transmission to sexual partners is not an issue.
4. Intermittent suppressive therapy – a combination of numbers 2 and 3 above, whereby the woman goes on suppressive therapy when in a relationship and then proceeds to intermittent treatment of episodes when she is no longer in a sexual relationship.

There are three antiviral medications available in Australia for the treatment of genital herpes. Aciclovir was first discovered in 1974, and was used extensively in the 1980s and 1990s before being superseded by famciclovir and valaciclovir, both of which have much better absorption and are the drugs of choice nowadays. Topical antiviral treatment does not work for genital herpes and should be avoided.

Transmission

The principal fear of people with genital herpes is transmission to a sexual partner. The risk of transmission can be reduced in the following three ways:

1. Avoiding sexual contact while lesions are present – although transmission occurs even when lesions are not present, when lesions are present there will be virus present on the skin/mucosal surface.
2. Using condoms – condoms reduce the risk of transmission if used faithfully, but are much less than 100 per cent effective.⁴
3. Taking suppressive antiviral therapy – valaciclovir has been shown in a large, randomised, controlled trial to halve the risk of transmission in heterosexual couples.

Pregnancy

Guidelines exist for the management of genital herpes during pregnancy and delivery, but the discussion of this topic is beyond the scope of this article.

Support

People with genital herpes may have significant psychosexual and relationship problems related to their diagnosis and the fear of transmission. Referral for counselling to a psychologist or counsellor who is knowledgeable about herpes can be very helpful for the patient (and the gynaecologist). In addition, self-help groups exist in some areas and websites have some very useful information and resources. Examples (which are operated by pharmaceutical companies) include: http://www.herpes.com.au and http://www.thefacts.com.au.