Must take caution with genital herpes

Dear Dr. Roach: I am a 75-year-old male in excellent health who is sexually active. During my thirties, I was exposed to the herpes virus 2, but recurrences now are extremely rare and mild. I use a condom during sexual intercourse and also take acyclovir beforehand. How long before intercourse should acyclovir be taken? If I take two 400-mg tablets instead of one, will that improve protection? Will acyclovir by itself provide enough protection so that a condom is not necessary? Finally, if my female partner takes acyclovir, will that help increase protection? — Anon.

There are conflicting answers to your questions, but here is my summary:

People with any history of genital herpes are at risk of shedding infectious virus, which can potentially infect a partner who has never had it. Although people with lesions are much more infectious, people with no symptoms at all can transmit the virus. Many people with genital herpes don’t even know they have it.

Acyclovir suppresses viral shedding — but the suppression isn’t complete, and takes about five days for maximum effectiveness. Valacyclovir reduced overall days of shedding from 11% of days to 3% of days. The studies I found to suppress shedding used acyclovir 400 mg twice daily.

In couples where one person had genital herpes and the other didn’t, chronic suppression did not reduce the likelihood of the uninfected partner getting herpes, but this study was done in people with HIV.

Condoms reduce transmission of genital herpes by about 30%.

Your partner taking medication to prevent infection makes some sense; however, I could find no good data to show how effective it might be.

Your partner should understand that despite you doing everything you can, she is still at risk.