Genitaler Herpes simplex

Siehe auch das separate Genitalherpes in der Schwangerschaft article.

What causes genital herpes? (Aetiology)

Genital herpes simplex is caused by infection with the herpes simplex virus (HSV). It is a lifelong infection with periodic reactivation. ¹

HSV is sub-divided into HSV type 1 (HSV-1) and HSV type 2 (HSV-2).

• Type 1 is the usual cause of infections of the oral region and causes cold sores (herpes labialis). In the UK, and in most of the developed world, it is now also the most common cause of genital herpes. In the US it is now the commonest cause of genital herpes in heterosexual women and in young people. ²

• Type 2 is associated with anogenital infection (penis, anus, vagina, vulva). It has historically been the most common cause of genital infection and remains so in Africa, South America, and South East Asia. ³ HSV-2 is the most likely to cause recurrent anogenital infection.

However, both can infect the mouth and/or genitals, due to oral sex or auto-inoculation.

Genital herpes simplex is one of the most common sexually transmitted infections. Up to 23% of adults in the UK have antibodies to HSV-2.

In the US, 22% of people aged 12 and over have been reported to have HSV-2 infection ⁵whilst other studies show that 27% of the adult population have genital ulceration caused by herpes simplex. ²

In 2016, 5% of the global population aged between 15 and 49 had at least one episode of genital ulceration caused by herpes simplex, of which 95% were caused by HSV-2 and 5% by HSV-1. ³

Globally in 2020, amongst people aged between 15 and 49, there were 25.6 million new cases of herpes simplex type 2 and 16.8 million new cases of genital herpes simplex type 1. This was in addition to 519.5 million people with pre-existing herpes simplex type 2 and 376.2 million people with pre-existing genital herpes simplex type 1. ⁶

The disease burden across the world, and the economic burden of treating and managing this, is significant. ⁷Although there is greater prevalence in LEDCs, there is greater economic burden in MEDCs with America and the Western Pacific bearing the greatest part of this. ⁸

In North West England there was a 13% increase in genital herpes simplex diagnoses between 2023 and 2024. ⁹

In England, in 2020, there were 20,530 cases of genital herpes simplex diagnosed in sexual health clinics which was a significant decrease, likely due to reduced activity of sexual health clinics and change in behaviours due to the covid pandemic.⁴

Transmission of genital herpes⁴

Genital herpes is acquired from contact with infectious secretions on oral, genital, or anal mucosal surfaces.

HSV-2 is generally transmitted via vaginal or anal sex and HSV-1 is usually transmitted through oral sex. However, genital herpes can also be transmitted via contact with lesions at other anatomical sites, such as the eyes and other non-mucosal surfaces (such as herpetic whitlow on fingers or other skin lesions).

A third of patients develop symptoms following exposure to HSV-2 and the incubation period is between 2 days and 2 weeks.

It is most common for transmission to occur from an asymptomatic patient - asymptomatic patients can still shed the virus from the external genitalia, anorectum, cervix, and urethra, and cause infection in the partner. Asymptomatic shedding is much more common in the first 12 months after infection.

HSV-1 shedding has been shown to decrease rapidly from 12.1% at 2 months to 7.1% at 11 months with shedding from the mouth being lower at 3.9%. Shedding has been shown to be higher from those with a primary infection than those with a secondary infection. Long term shedding with HSV-1 has been shown to be uncommon but still occurs.²

HSV-2 shedding is much more common and is associated with an increased rate of symptomatic infection.²

Because long-term shedding can occur, and because asymptomatic transmission is very common, transmission from asymptomatic individuals (many of whom are unaware that they are infected) in monogamous relationships can occur after several years and can cause considerable distress.

Risk factors for genital herpes infection⁴¹⁰

• Multiple sexual partners.

• Previous history of STIs.

• Early age of first sexual intercourse.

• Unprotected sexual encounters.

• Men who have sex with men (and female partners of men who have sex with men).

• Weibliches Geschlecht.

• Human immunodeficiency virus (HIV) infection.

It is estimated that 20% of patients with genital HSV are genuinely asymptomatic, either having no visible lesions or lesions only on the cervix where they are not visible and do not cause pain.¹¹

It is estimated that another 60% have lesions which are atypical and not recognised by the patient or their doctor as being caused by HSV.

20% of people have classical symptoms which include painful genital ulcers, sores, crusts, tender lymphadenopathy, and dysuria. Classically, mucous membrane lesions progress to vesicles and pustules that often last up to 3 weeks. Genital lesions can be especially painful, leading to swelling of the vulva in women, burning pain, and dysuria.⁵

Primärinfektion

• The initial acquisition of the virus is known as the primary infection.

• As stated above, this may be asymptomatic.

• Symptome umfassen:

  • Tingling neuropathic pain in the genital area/buttocks/legs.

  • Extensive painful crops of blisters/ulcers in the genital area (including the vagina and cervix in women and the urethra in men).

  • Tender inguinal lymph nodes.

  • Localised oedema.

  • Dysurie.

  • Vaginal or urethral discharge.

• Febrile flu-like prodrome (5-7 days) occurs in up to 24% of patients. Myalgia and fever are the main systemic symptoms.⁵

• Systemic symptoms are more common in primary disease than in non-primary or recurrent disease.

• It may last up to 3-4 weeks.

Wiederkehrende Infektion

• Following primary infection, the virus becomes latent in local sensory ganglia near to the skin.

• There is periodic reactivation during which the virus moves from the ganglia to the skin. While the virus is in the skin, the patient may experience lesions (symptomatic shedding) or there may be no visible lesions (asymptomatic shedding). Reactivation experienced as symptomatic and asymptomatic shedding is always infectious.

• Episodes are usually shorter (up to 10 days).

• Symptoms may be mild and self-limiting.

• Median recurrence rate after a symptomatic first episode is:

  • HSV-2: 0.34 recurrences per month (roughly four attacks in the subsequent 12 months).

  • HSV-1: 0.08 recurrences per month (roughly one attack in the subsequent 12 months).

• Symptomatic and asymptomatic viral shedding become less frequent over time; however, it is possible to transmit the virus more than ten years after initial infection.²

It is important to confirm diagnosis and identify the type of HSV involved. This will affect management, prognosis, and counselling.

Detection and identification of the virus¹⁰

Tests are carried out in sexual health clinics in the UK. Tests should not be carried out in general practice. Tests may include:

• DNA detection using polymerase chain reaction (PCR) of a swab from the base of an ulcer.

• HSV serotyping.

• HSV antibody tests.

• Other STIs:

  • Gonorrhoea.

  • Nicht-gonorrhoische Urethritis.

  • Syphilis. (Ulcers are painless.)

• Skin conditions:

  • Krätze (produces excoriation but not vesicles).

  • Psoriasis.

  • Kontaktekzem oder atopic dermatitis.

  • Folliculitis.

  • Lichen sclerosus.

• Reaktive Arthritis.

• Behçet-Syndrom.

• Genital malignancy.

• Herpes zoster (usually unilateral and confined to one dermatome, although recurrent HSV may also follow this pattern).

• Morbus Crohn.

• Vulvo-vaginal candidiasis (over half of the women infected with HSV are thought to be diagnosed wrongly as having candidiasis or other causes of vulvitis).

• Sexual trauma.

There is no cure for genital HSV. Infection is lifelong although most people will eventually stop having recurrences.

Überweisung

Anyone with suspected genital herpes should be referred to a genitourinary medicine (GUM) clinic. They can usually self-refer. This allows accurate diagnosis, treatment, screening for other STIs, appropriate counselling, advice about recurrence, advice for partners and suitable follow-up.

Unterstützende Verwaltung

Advice includes:

• Saline bathing (one teaspoon of salt in one pint of warm water).

• Oral painkillers.

• Topical lidocaine 5% gel or ointment is suitable analgesia. Benzocaine, however, causes significant sensitisation and so should not be used.¹³

• Vaseline® or topical lidocaine may be applied to prevent pain during micturition.

• Micturition whilst sitting in a bath can help prevent urinary retention.

• Increase fluid intake to dilute urine to reduce pain during micturition.

Antiviral therapy

Topical antivirals have poor efficacy and have been found to lead to resistance. They therefore should not be used.¹³

Oral anti-herpes viral treatment should be given within five days of the onset of symptoms or if new lesions are still forming.

The British Association for Sexual Health and HIV (BASHH) guidelines¹⁰ advise first-line treatment should be five days of:

• Aciclovir 400 mg three times daily; OR

• Valaciclovir, 500 mg twice daily

The European guidelines also include the options of five days of:

• Aciclovir 200 mg five times daily; OR

• Famciclovir 250 mg three times daily.

and recommend that choice should be made based on availability, cost, and likely compliance.¹³

Antiviral therapy reduces the severity and duration of episodes but does not alter the natural history of the disease

Management in people with HIV

This requires specialist advice. More detailed information is given in the BASHH guidelines.

Management in children

The presence of genital ulceration in a child has a broad differential diagnosis as listed above. HSV-1 in children is not necessarily sexually transmitted as it can be auto-transmitted.¹⁴

However, the presence of such lesions in a child should always prompt the clinician to consider sexuellen Missbrauch.¹⁵

This consideration involves:

• Looking for other alerting features of abuse in the history and presentation.

• Discussing the case with a more experienced clinician and/or a designated professional for safeguarding children (and then referring if appropriate).

Following a referral, the paediatrician would gather collateral information from other health agencies and disciplines, and ensure review.

The presence of genital ulceration in children should prompt a screen for other STIs. Examination of a prepubertal child should only be undertaken by an experienced paediatrician, a suitably qualified forensic practitioner, or a GUM physician with appropriate expertise.¹⁶

Recurrence of infection usually causes less severe symptoms, which are more rapidly self-limiting.

Options for management are:

• Supportive measures alone (as described above).

• Antiviral therapy as required (episodic treatment).

• Suppressive therapy.

Episodic antiviral treatment

Oral aciclovir, valaciclovir, and famciclovir have all been shown to reduce duration (by a median of 1-2 days) and severity of episodes of genital herpes. No advantage has been shown of one therapy over another. Short-course therapy has been found to be equally effective as five-day treatment. The earlier the treatment is started, the more effective it is likely to be. Therefore, people with recurrent genital herpes should have a course pre-prescribed so they can start it as soon as they feel the earliest symptoms developing.

BASHH advises the following short courses as options for first-line therapy:

• Aciclovir 800mg three times a day for two days.

• Famciclovir 1 g twice daily for one day.

• Valaciclovir 500 mg twice daily for three days.

Alternative five-day courses are:

• Aciclovir 200 mg five times daily.

• Aciclovir 400 mg three times daily.

• Valaciclovir 500 mg twice daily.

• Famciclovir 125 mg twice daily.

Suppressive antiviral treatment

• May be needed (usually if >6 attacks per year).

• Usual treatment is aciclovir at a dose of 400 mg twice daily or 200 mg four times daily.

• Alternatives are famciclovir 250 mg twice daily or valaciclovir 500 mg once daily. A Cochrane review found no evidence to suggest efficacy of one treatment over another.¹⁷

• Choice of treatment depends on cost, local guidelines and adherence.

• Consider the frequency of attacks and symptoms vs the cost and inconvenience of treatment.

• The suppressive effect takes five days of therapy to establish.

• Discontinue after 12 months to reassess attack frequency. The minimum period of reassessment should include two further attacks. This is because discontinuing suppressive treatment commonly sets off a recurrence. If the recurrence rate is unacceptably high, suppressive treatment can be restarted.

• Suppressive treatment also reduces the risk of asymptomatic shedding.

The following need to be covered (usually by the sexual health clinic):

• Natural history of genital HSV. Explain it is possible to get genital herpes even if your partner has never shown any sign of infection. Explain the latent phase. Explain the role of asymptomatic viral shedding in sexual transmission (more common in genital HSV-2 and in the first year after infection). Stress the fact that a first episode of genital HSV does not necessarily imply recent infection.

• The need to inform current or new sexual partners (ensure that this is clearly documented in the notes).

• Use of antiviral drugs for symptom control, including prescription in reserve for recurrent attacks and possible longer-term suppressive treatment.

• Reassurance that transmission cannot occur from sheets, towels, swimming pools, etc.

• Avoidance of sexual contact during symptomatic recurrences and prodromal phase.

• The use of condoms. Condoms reduce (but do not completely prevent) the risk of transmission.

• Pregnancy - the importance of not transmitting HSV to a pregnant woman should be stressed. Any woman with a diagnosis of genital herpes, or whose partner has genital herpes, should advise their GP and midwife of this at her first antenatal appointment, to consider how best to reduce the risk of neonatal infection. For more details see the separate article Genitalherpes in der Schwangerschaft.

Consider suggesting support from the Herpes Viruses Association, which has web-based information and a telephone helpline.¹⁸

• Autonomic neuropathy, resulting in urinary retention.

• Aseptic meningitis.

• Spread to extra-genital areas.

• Secondary infection with candida or streptococci.

• Perinatal transmission may cause serious complications in the neonate. See the separate Genitalherpes in der Schwangerschaft article.

• Psychological and psychosexual problems.

• In people with HIV with primary infection and no HIV therapy, there may be development of severe/prolonged mucocutaneous lesions. Other serious or life-threatening complications have been reported in this scenario - for example, fulminant hepatitis, pneumonia, neurological disease and disseminated infection.

There are no vaccines against HSV.

Transmission of HSV may be reduced by the following:

• Reduction in the number of sexual partners.

• Use of condoms, which reduces but does not completely prevent transmission.

• Avoidance of sex with someone who has active genital herpes or active oral herpes (although viral shedding and transmission also occur from asymptomatic infections).

• Antiviral drugs, which may reduce transmission to partners. They are thought to reduce symptomatic and asymptomatic viral shedding by 80-90%.