Herpes Transmission Cut; Study Indicates new Drug Can Help Protect Partner

Houston researchers have found that medicine taken to treat herpes outbreaks also cuts the odds of transmitting the disease to a sexual partner nearly in half.

Houston researchers have found that medicine taken to treat herpes outbreaks also cuts the odds of transmitting the disease to a sexual partner nearly in half. The study, published this week in the New England Journal of Medicine, is also notable because no drug previously has been shown to reduce the transmission of a sexually transmitted disease from one partner to another. “It’s the first time that any medication taken by a person has benefited a partner,” said Dr. Stephen Tyring, professor of dermatology, microbiology and immunology at the University of Texas Medical Branch at Galveston, who co-authored the study. Genital herpes is common in the United States. According to the Centers for Disease Control and Prevention, at least 45 million people ages 12 and older – one out of five adolescents and adults – have had a genital infection. Between the late 1970s and the early 1990s, the number of Americans with genital herpes infection increased 30 percent. Most herpes carriers don’t know they have the virus because they lack noticeable symptoms such as visible sores or painful lesions. Tyring and his colleague studied 1,484 monogamous, heterosexual couples. One partner was infected with herpes and the other partner not. For the eight-month study, the herpes-infected partner in half the couples took valacyclovir, sold under the brand name Valtrex, and the other half took a placebo. Partners who took the drug once a day had a 1.9 percent chance of transmitting the disease to their partner. Those who took a placebo had a 3.6 percent chance of transmission during the test period, about the normal rate. The couples came from 37 different countries, but the highest enrollment, more than one-tenth of participants, was from the Houston area. “You still have to be careful, but this research gives some reassurance to people who do have genital herpes that they can have normal, healthy relationships,” said Dr. Patricia Lee, who consults with herpes patients in the Houston region. Tyring said some patients, instead of just using the drug during herpes outbreaks, already take valacyclovir every day because it has also been shown to reduce the total number of outbreaks. It is possible to transmit herpes both during and between outbreaks. Although effective, the drug is expensive. Daily use can cost more than $1,000 a year if a person does not have insurance. One alternative to the medication may be a herpes vaccine that Tyring and his research group are now testing. Early results, published last year, suggest the vaccine is safe and effective, but there’s a catch – it protects only women. Tyring said part of the follow-up study is trying to determine why it doesn’t protect men. (Source: Houston Chronicle, MEDLINE Plus, New England Journal of Medicine, Jan, 2004)