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Posted by: lammylady on 2008-10-11, 04:33:40
I can't give you a risk per single event. You are right that condoms provide little protection for the man. The most often quoted figure for the risk-reduction condoms offer is 40%, but that takes into account that condoms offer much more protection to a woman with an infected male partner than to a man with an infected female partner. I have seen some herpes specialists estimate that condoms provide as little as 0-20% protection against herpes for a man with an infected female partner. I have certainly come across quite a few men who say they caught herpes while using a condom. While condoms don't always cover the potential sites of viral shedding, they offer some useful protection against the virus by protecting or covering the mucous membranes that are the most likely sites of transmission. One antiviral medication for herpes, valacyclovir (Valtrex®), has been shown to reduce the risk of herpes transmission. When a person with a history of recurrent genital herpes takes 500 mg of valacyclovir daily, it can reduce the risk of transmission to a partner who does not have the virus by 50%. In people who get recurrences, asymptomatic shedding occurs on average for 2 per cent of the time for people with type 2 infection and 0.7per cent of the time for those with type 1. The fewer recurrences a person has, the less chance there is of asymptomatic shedding. Asymptomatic shedding tends to diminish over the years. It is more likely to be happening in the first year and much less probable after that. The virus is most often transmitted during the first four months of a new relationship; however partners are often together for years without the virus passing from one to the other. I have been trying to find reports for you, and the following are extracts from reports that have appeared in the British Medical Journal: "Mertz et al showed that the mean transmission rate was 9.7% a year, with higher rates when the exposed partner was female or was previously uninfected with herpes simplex virus of either type... seventy per cent of these transmissions occurred as a result of sexual contact during periods of presumed subclinical viral shedding. " "Subclinical shedding–viral shedding not associated with genital lesions – occurred in 55% of women with herpes simplex virus type 2 and 29% of women with herpes simplex virus type 1 during the study period. The median number of days during which virus shedding was recorded was 1.1%. Half of the episodes of subclinical shedding occurred within seven days of a symptomatic recurrence. "Subclinical viral shedding was more common among women with frequently recurring herpes (more than 12 symptomatic recurrences a year) or who had acquired their infection in the previous year. " "Wald et al showed that women with recurrent genital herpes who took continuous suppressive aciclovir treatment not only reduced their likelihood of symptomatic recurrence but also had fewer days of subclinical virus shedding than when they took placebo. The number of days of subclinical viral shedding for subjects taking aciclovir was six out of 1611 (0.4%) compared with 83 out of 1439 (5.8%) for those taking placebo. " So, in other words: -if your girlfriend has hsv-2 she will be infectious for about 2% of the time when she is showing no symptoms. -your risk of catching it from her, if you practiced UNprotected sex but avoided contact during outbreaks would be about 9.7% a year - a year, not per each contact. -she is more likely to be infectious if she gets lots of outbreaks than if she gets very few -the risk is higher if she has caught herpes in the last year, and lower if she has had it longer -condoms don't offer much protection, but offer some, and protect the more vulnerable mucous membrane -valtrex, an antiviral drug she can take, lowers the risk of spreading significantly - by at least 50% and maybe by much more If she has genital hsv-1 and not genital hsv-2, the risk is much lower. Also. remember that one in four women currently have genital hsv-2 so your girlfriend is hardly the only one, and probably not the only girl you have dated that has it. 80% -90% of women infected with herpes are unaware of it. I have genital hsv-1. Hsv-1 is the virus that usually causes facial cold sores, and is carried by about 80% of adults. On the face, it is approximately as infecitous as genital hsv-2, and yet most people do not use barriers for oral sex. My boyfriend was aware he had oral hsv-1, so although I had oral and oral-genital contact with him regularly, he was very careful to avoid contact when he had symptoms. I did catch it from him eventually, but it was after 7 years of unprotected contact. Although it took me 7 years, I was friends at college with another girl who caught genital hsv-1 through oral sex with a partner who did not have current symptoms, just as I did. But she caught it thr first time they ever had oro-genital contact, while for me it took a long time. So the previous answerer is right to say percetages are completely meaningless, because like her you could just be the unlucky one, or you could never catch it. You do need to be aware that, even if you use condoms and she takes valtrex, there is still a risk of about 2% a year that you will catch it, but many couples where one has herpes are together for many years without spreading the virus. |
