Un médicament pour remplacer le préservatif? Le rêve fou d’une équipe de chercheurs américains

By Stephen Pincock

SYDNEY (Reuters Health) Jul 23 - HIV-positive men can conceive children naturally, without infecting their partners, if their viral load is fully suppressed by antiretroviral therapy and the partner takes a dose of tenofovir before intercourse, according to the results of a small study presented Monday.

Dr. Pietro Vernazza and his colleagues from St. Gallen Hospital in Switzerland studied 21 serodiscordant couples where the male partner was HIV-positive and the female partner was not. They described their results here at the International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention.

All of the couples in the study wanted to have children; the men were already taking antiretrovirals that suppressed their serum HIV below the detectable level.

To further reduce the risk of infection in the female partners, the researchers gave each of them two doses of tenofovir, one to be taken 36 hours before intercourse and another 12 hours before.

After each of the couples had made three attempts, 11 of the 21 couples had conceived, Dr. Vernazza said, and after 10 attempts, 15 were pregnant. These are substantially higher rates than might be expected with artificial reproduction, Vernazza said.

All the women in the study tested negative for HIV, 3 months after the last exposure, the researchers report. "The risk of transmission in a couple with a fully treated male partner is low and can further be reduced by timed intercourse and a short pre-exposure prophylaxis with tenofovir," Dr. Vernazza said.

"This system actually worked pretty well," he told delegates at the conference. One of the main issues the researchers faced was convincing patients the approach was safe, he said.

"Persuasion of the patients might sometimes be a problem, in which case we still offer them in vitro fertilization (with sperm washing)," he said. "But in general, an hour to explain all the data is enough."

Large scale trials examining pre-exposure prophylaxis as a way to reduce the spread of HIV are currently underway in Botswana, Thailand, Peru and Ecuador, with the first results expected next year, the president of the International AIDS Society, Dr. Pedro Cahn, told reporters ahead of the conference.