by Dr Laura Waters, a GU doctor at the Chelsea & Westminster
On Saturday 17th September [2005], Dr Laura Waters gave us a talk on ‘Herpes simplex –transmission and prevention’ supported by a ‘PowerPoint’ presentation. She covered herpes simplex from diagnosis, through symptoms (with photos!), treatment and transmission.
Incidence
- At sexual health (GUM) clinics, more than 80% of people attending (not for herpes simplex) have antibodies to herpes simplex type 1.
- 50% of new cases of genital infection are caused by herpes simplex type 1.
- 20% of sexually active adults have herpes simplex type 2.
- Most of these people with herpes simplex are unaware of it:
- One in four will have clinical symptoms significant enough that s/he seeks diagnosis and
treatment; - Two in four will recognise their symptoms after a counselling session describing all the
variations they might have; - One in four has no recognisable symptoms – however even s/he has symptoms eventually.
Typical symptoms
It starts with flu-like illness and then blisters develop, burst and heal. However some patients may have symptoms that are more like:
- recurrent cystitis
- thrush
- eczema
- sweat rash
- flu
Dr Waters told us that when doctors diagnose by appearance only [no swab test results] then they are likely to be wrong two thirds of the time!
Serological testing [blood test for herpes simplex antibodies]
The test is not used to diagnose herpes simplex as it takes 8 to 12 weeks for the antibodies to be formed. So this test cannot be done during the first illness.
Partners of people who know they have herpes simplex can have this test at Chelsea & Westminster Hospital: if the partner tests positive then s/he cannot catch it again and they do not have to take care with prevention. [You will not reinfect the partner you caught it from, on any part of his/her body.] According to 200 patients at Leeds GUM questioned by Fairley and Monteiro (1997), 92 per cent expect to be tested for herpes simplex when they go for a check-up. The reasons that the serological test is not part of a check-up are:
- the test is only 95% accurate and is less accurate in people who are unlikely to be infected (and conversely more accurate in people who have been more at risk)
- as a result of the this inaccuracy, medical staff are unsure how to explain the results to patients
- tests cost around £25.00
- a proportion of people don’t want to know (if they are not getting symptoms, they cannot protect partners anyway)
Types 1 and 2
The virus remains latent [asleep] in the sensory nerve ganglion [junction box] near the spine at the level where infection occurred. Recurrent symptoms occur in the area served by that ganglion.
Frequency of genital recurrences
- Type 1 recurs on average 0.08 times a month in the first year, in other words: once a year
- Type 2 recurs on average 0.34 times a month in the first year, i.e. 4 times a year.
Treatment
Aciclovir is the most commonly used antiviral therapy. It can be taken just when you have an outbreak, or on a regular basis to prevent outbreaks. When lecturing to doctors, Dr Waters explains to them that it can be used:
- to control symptoms
- where there is complicated disease [such as urine retention, or erythema multiforme*]
- when the patient has relationship concerns i.e. in a new relationship
- where patients have multiple partners
- to reduce transmission
- to prevent an outbreak when giving birth – however C-sections are not necessary even if there is a recurrence at term.
Aciclovir has been under surveillance for 13 years and has shown no health implications. When a person stops taking it, they should expect a rebound outbreak 4-5 days later.
A trial followed 1484 couples, where the partners were all at risk of contracting herpes simplex. In the course of a year, taking antiviral drugs every day lowered the risk of infecting the partner from 3.6% risk to 1.9% risk. The drug used was Valtrex as this drug is still under patent. However herpes specialists are confident that taking aciclovir would give the same result. [This is relevant to patients as Valtrex costs the NHS five times more than aciclovir, so doctors are more likely to prescribe aciclovir.] No trial will be done with aciclovir as this is now a generic drug, so that no one drug company would make a large profit from this drug.
Asymptomatic shedding
Over the course of 6 months, women rubbing a swab around their genitals twice a day were found to have virus present on 6% of days without drugs and on 0.4% of days if they were taking antiviral pills.
Asymptomatic shedding occurs less over time: 10% in first year – less in following years. It occurs less in people with fewer symptoms [and more in people with more symptoms.]
Solution
Dr Waters wound up her talk by telling us that the solution to herpes simplex will be a vaccine still to be developed, that would prevent it being caught in the first place. Tests are proceeding on young women. [This vaccine did not work out and has been shelved.] She did not expect new drugs to be available in the near future but hoped that existing drugs and tests would be used more extensively.
She ended by pointing out that destigmatising herpes simplex would be the ultimate solution.
Report compiled from Dr Waters talk by Marian Nicholson