Second study finds treating herpes won't stop HIV

WASHINGTON (Reuters) - A second study has found that treating genital herpes infections does not protect people from the AIDS virus.

File photo shows blood samples taken for HIV tests are seen inside a GHESKIO (Le Groupe Haitien d'Etude du Sarcome de Kaposi et des Infections Opportunistes) center in Port-au-Prince, March 12, 2008. REUTERS/Eduardo Munoz

The study, published on Wednesday in the New England Journal of Medicine, casts even more doubt on the once hopeful idea that treating the common infection might help put a dent in the AIDS pandemic.

Dr. Deborah Watson-Jones of the London School of Hygiene and Tropical Medicine and colleagues reported on 659 workers aged 16 to 35 at recreational facilities in Tanzania.

They were asked to take two pills a day of acyclovir, an antiviral drug that can suppress painful outbreaks of herpes simplex 2, responsible for genital herpes.

Herpes simplex 2, or HSV-2, has been shown to raise the risk of HIV infection by as much as 69 percent, so many groups had been testing the idea that treating it might reduce the rate of HIV transmission.

“In Tanzania, an estimated 74 percent of new HIV infections in men, 22 percent in woman and 63 percent in bar and hotel workers are attributable to HSV-2,” Watson-Jones and colleagues wrote.

And HIV is common in Tanzania, infecting 6.5 percent of Tanzanians aged 15 to 49.

“It reaches 40 percent in high risk groups such as workers in bars and guesthouses, who may supplement their income by offering sex in return for money or gifts,” the researchers added, noting that few use condoms.

However, the women given two acyclovir pills a day were not any less likely to become infected with the AIDS virus than women given placebos.

“These data show no evidence that acyclovir as HSV suppressive therapy decreases the incidence of infection with HIV,” the researchers wrote.

They said that the dose given may not be powerful enough to suppress it, and noted that urine tests suggested many were not taking the pills as prescribed.

The AIDS virus infects an estimated 33 million people globally. It has killed 25 million and there is no cure and no vaccine.

Reporting by Maggie Fox; Editing by Will Dunham and Eric Beech