Treating herpes doesn't prevent HIV

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Treating herpes doesn't prevent HIV

By Cheng AP Medical Writer / June 20, 2008

LONDON—Doctors have long suspected that people with herpes are more likely to

catch HIV. So they thought that by treating herpes, they could also cut a

person's HIV risk. But a new study that tested this strategy found the

assumption may have been wrong.

" It's a significant, disappointing finding, " Francis Ndowa, coordinator of the

sexually transmitted infections control team at the World Health Organization,

said in an interview.

Ndowa was not connected to the research, published Friday in the medical journal

The Lancet.

The finding may spark a rethinking of HIV prevention strategies in Africa, where

controlling sexually transmitted diseases such as herpes is usually part of

general AIDS prevention plans.

Researchers tracked more than 3,000 men and women infected with herpes in

Africa, Peru and the United States. Roughly half were treated with aciclovir, an

antiviral that stops herpes ulcers.

After a year and a half, the scientists found that 75 people out of the 1,581

who had been receiving aciclovir were later infected with HIV. Of the 1,591

people who received placebo pills, 64 contracted HIV.

In the trial, researchers chose participants who had herpes and who faced

similar risks of getting AIDS. The study also questioned the participants during

monthly visits about risky sexual behavior with their recent partners.

The study was paid for by the United States' National Institute of Allergy and

Infectious Diseases, other U.S. government institutes, and by GlaxoKline

PLC, which sells aciclovir as Zovirax.

A small study in Tanzania last year also suggested that treating herpes didn't

help reducing HIV susceptibility.

But that doesn't necessarily mean that the theory of treating herpes to avoid

HIV is incorrect, experts said.

" It's probably likely that we need considerably more potent interventions than

we have, " Connie Celum, a professor of global health and medicine at the

University of Washington who led the Lancet study, told The Associated Press.

Experts said there was a complex relationship between the two viruses that is

still not entirely understood.

When herpes ulcers erupt, that draws white blood cells to the skin to fight the

virus. Unfortunately, those white blood cells also have receptors for HIV.

Ndowa said it was possible that even without the telltale ulcers, herpes might

have lingered while patients were taking the aciclovir, allowing HIV to gain a

foothold.

In an accompanying commentary in the Lancet, H. Gray and J. Wawer

of s Hopkins University said it was questionable whether controlling

sexually transmitted infectious could work to prevent HIV.

" It is time to reassess the hypothesis and to adjust prevention policy

accordingly, " they wrote.

But Ndowa and Celum said the strategy of fighting herpes to prevent AIDS might

work, if a different dosage or more powerful drug was tried.

" We don't exactly know why this didn't work, but this approach still has

potential, " Ndowa said. " Maybe it was just too much to expect from a tablet

taken twice a day that it could be effective against HIV. "

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