March 24, 2003 (San Francisco) -- In the 1970s, herpes was forever. In the 1980s, it was the "gift that kept on giving." But while herpes is still forever, new research suggests that in the 21st century genital herpes treatments can help prevent spread of this sexually transmitted disease.
"This is the first time that antiviral therapy has demonstrated the ability to prevent or reduce transmission of a virus," researcher Gisela Torres, MD, of the University of Texas Medical Branch Center for Clinical Studies, tells WebMD.
Torres studied close to 1,500 something monogamous couples in their 30s in which one partner was infected with genital herpes. In half of the couples the infected partner took 500 mg of the genital herpes drug Valtrex, while the infected partners in the remaining couples were given placebos. The study was funded by GlaxoSmithKline, a WebMD sponsor.
In the group that took the genital herpes treatment, spread of symptomatic herpes to the partner was 77% less than in the group that took placebo, says Torres. The researchers also looked at silent spread of genital herpes since the virus is often transmitted without the partner developing any symptoms. Treatment with Valtrex reduced the rate of silent transmission by 50%.
Overall, the transmission rate was 3.8% in the placebo group and 1.9% in the Valtrex group, she says.
Torres, who presented the research at the 61st annual meeting of the American Academy of Dermatology, says several factors contribute to transmission.
"The risk for transmission increases as sexual activity increases. In this study, transmission was significantly higher among couples who had sex more than 10 times a month compared to those who limited intercourse to no more than five times a month," she says. "But even in this case, [Valtrex] was protective so that the transmission rate among highly sexually active couples was less if the infected partner was taking antiviral therapy."
The rate of herpes infection has been steadily increasing for the last 20 years and research suggests that 1 in 5 adults has genital herpes. Herpes can be spread even when the infected person has no sores or irritations from the disease. With silent transmission a real risk, Torres says the need for genital herpes treatments to suppress the virus and prevent spread is especially urgent.
Of particular concern are women of childbearing age who can pass along the infection during pregnancy. If a child is born with herpes, "there is a risk for serious complications and even death," says Torres.
"If the woman is the positive partner, she should be on antiviral therapy for the last trimester of her pregnancy so that she reduces the risk for viral shedding during delivery. If the woman is the uninfected partner, we would advise the couple to begin suppressive therapy before considering pregnancy," said Torres.
Herpes is a disease of recurrent outbreaks and some people have flare-ups 10 or more times a year. In this study, patients averaged five recurrences a year before genital herpes treatment. After eight months of treatment, 60% of Valtrex patients had no outbreaks compared with 20% of placebo patients.
Peter Heald, MD, professor of dermatology at Yale-New Haven Hospital in New Haven, Conn., says the results are impressive, but he questioned the safety of "a lifetime of [Valtrex] treatment." Torres says that other studies demonstrate that antiviral therapy is "safe up to 10 years."
Warren Heymann, MD, dermatologist at Cooper Hospital/University Medical Center in Camden, N.J., says, "This treatment should be considered for all affected couples of child-bearing age."
But the genital herpes treatment is not cheap: Each pill costs $2-$3. "Figure $1,000 a year for treatment," says Torres' co-researcher Mathijis Bretjens, MD, also of the University of Texas Medical Branch. "But our experience is that insurers are willing to pay for the treatment, and even if coverage is denied, patients will pay for this protection."
Torres says that other genital herpes drugs may also be effective at reducing the risk for transmission.
SOURCE: 61st Annual Meeting of the American Academy of Dermatology, San Francisco, March 24, 2003. Gisela Torres, MD, University of Texas Medical Branch Center for Clinical Studies. Peter Heald, MD, professor of dermatology, Yale-New Haven Hospital, New Haven, Conn. Warren Heymann, MD, dermatologist, Cooper Hospital/University Medical Center, Camden, N.J. Mathijis Bretjens, MD, University of Texas Medical Branch.