HIV drugs prevent infection in African study

WASHINGTON (Reuters) - People across Africa who took AIDS drugs were far less likely to infect their partners with the virus, researchers said on Wednesday.

The study, presented at a meeting of AIDS experts, is one of the first to show so clearly that the drugs can prevent infection as well as keep patients healthy.

It could boost efforts to provide the AIDS drugs to people, especially in the hardest-hit countries in Africa.

Dr. Deborah Donnell of the Fred Hutchinson Cancer Research Center in Seattle and colleagues followed 3,400 couples in which one partner was infected and the other was not in seven African countries.

The couples were all counseled on how to protect themselves and given free condoms. Each patient with HIV began taking a drug cocktail when he or she became eligible based on a measure of immune system damage called CD4 count.

Over the next one to three years, 103 of the previously uninfected people became infected. Nearly all, 102 infections, happened before the infected partner started taking the drugs, Donnell told the Conference on Retroviruses and Opportunistic Infections in San Francisco.

"Only one happened when the partner was on antiretroviral therapy," she told reporters in a telephone briefing.

"That amounts to a final reduction of 92 percent when on antiretroviral therapy."

The AIDS virus infects 33 million people globally and has killed 25 million since the pandemic began in the 1980s. There is no cure and no vaccine but combinations of drugs called antiretrovirals can keep patients healthy.

There is a debate over whether treating patients also reduces the likelihood that they will infect others. It is an important point as governments and non-profit groups spend billions on treatment and prevention programs.

"We think it is very likely that antiretroviral treatment is going to reduce the risk of HIV transmission," Donnell said. "Our data will be informative for policymakers."

Donnell said the study was unique as the couples were followed closely and tested every few months. Tests showed whether newly infected partners were actually infected by their sexual partner or by someone else.