Facebook Twitter



Oral sex may not be safe sex, despite the belief of some that it poses a small risk of spreading the AIDS virus, researchers reported.

The study, which involved exposing monkeys to an AIDS virus in controlled laboratory experiment, showed that viral infection occurred through oral exposure with fewer virus particles than in controlled experiments of rectal exposure.In effect, said Dr. Ruth M. Ruprecht, "this study shows that people need to know that oral sex is not safe sex.

"This is important public health information that should be widely published," said Ruprecht, a virologist at the Dana-Farber Cancer Institute in Boston and the senior author of a study published today in the journal Science.

Earlier studies have hinted that receptive oral sex represented a risk for HIV infection, Ruprecht said. But many people have thought infection could occur only if the receiving partner had cuts or sores in the mouth. Many people, she said, assumed that oral sex was a safe alternative to other forms of intercourse.

"I've talked with physicians who work in AIDS clinics who felt that oral sex is not that much of a risk," said Ruprecht.

"On the basis of reports on humans and on our study, unprotected receptive oral intercourse should be added to the list of behaviors that place people at risk for infection by HIV," she said.

Ruprecht led a laboratory team that experimentally exposed monkeys to the simian immunodeficiency virus, or SIV, a virus closely related to HIV, the virus that causes AIDS.

Six of seven monkeys that received doses of SIV virus at the back of the tongue developed simian AIDS disease. And the minimum dose of SIV to cause infection through oral exposure was less than the minimum dose required to cause SIV infection through rectal exposure, Ruprecht said.

However, Dr. Ronald O. Valdiserri, an expert on HIV transmission at the Centers for Disease Control and Prevention, noted that the monkey study was not a true model for human exposure to HIV.

"It was an experimental condition, so you cannot have a 100 percent correlation," he said.