UNM Health Sciences Center researchers participated in an international study showing that suppressive drug therapy can reduce the transmission of genital herpes. The UNM HSC study was directed by Dr. Gregory Mertz and Dr. Elaine Thomas.
Data presented at the 42nd the Interscience Conference on Antimicrobial Agents and Chemotherapy on September 27, 2002 showed that once-daily suppressive therapy with valacyclovir (marketed as Valtrex) reduced transmission of symptomatic genital herpes by 77 percent in healthy heterosexual monogamous couples where one partner had the disease. In addition, suppressive therapy reduced the overall acquisition of the virus (determined by a positive blood test and/or laboratory confirmation) by 50 percent.
"This is the first drug therapy that has been clearly shown to decrease the risk of transmission of a sexually transmitted disease between sex partners. We now can tell patients that daily suppressive therapy not only provides clinical benefit to the person with recurrent genital herpes by reducing the frequency of their outbreaks, but it also clearly reduces the risk of transmission of genital herpes to their sex partner," said Mertz, professor in the School of Medicine Department of Internal Medicine and UNM lead researcher.
Transmission of genital herpes to a sexual partner is a major concern to patients. The study compared the drug and placebo for the reduction of risk of transmission of genital herpes, herpes simplex virus type 2 (HSV-2), in heterosexual monogamous couples where one partner had genital herpes (source partner) and the other did not (susceptible partner). A total of 1,484 couples were included in the intent-to-treat population. The volunteers were randomly given either daily valacyclovir or dummy pills, offered advice on using condoms and then followed for eight months.
Two percent of those taking Valacyclovir passed on the virus to their partners, compared with four percent on dummy pills. The susceptible partner was tested once a month and told to visit the clinic at the first sign of an outbreak. All couples were provided with condoms and counseled on safer sexual behavior at all study visits.
The treatment nearly eliminated herpes symptoms in the partners, even if they caught the virus. Just half of one percent of those whose infected partners took valacyclovir got herpes sores, compared with two percent in the comparison group. The effect of valacyclovir on transmission of genital herpes has not been studied among individuals with multiple partners, non-heterosexual couples, and couples not counseled on using safer sexual practices.
The study was sponsored by GlaxoSmithKline, maker of Valtrex. The drug is currently indicated for the initial and recurrent treatment and for suppression of genital herpes outbreaks and for the treatment of cold sores and herpes zoster (shingles).
About Genital Herpes
Experts estimate that genital herpes, which is a contagious, lifelong disease, affects up to 60 million Americans or one in five people over the age of 12. However, nine out of ten of those are unaware they have genital herpes and may only have experienced a mild initial outbreak without recognizing recurring symptoms of the disease.
Though the disease is most contagious during an outbreak, symptoms do not have to be present to infect someone else. In fact, experts confirm most transmission of genital herpes occurs without symptoms being present, known as asymptomatic viral shedding, and when the infected person is unaware of being infectious.
While genital herpes is not a life-threatening disease, the virus never leaves the body, making it a lifelong condition that can recur at various times with or without symptoms. Symptoms of genital herpes may include a cluster of blisters, bumps or rashes in the genital area, or on the thighs or buttocks. To help prevent spreading the disease to others, sexual contact should be avoided during outbreaks and following safer sex practices, including the use of condoms, is recommended.
Contact: Cindy Foster, 272-3322