Mitrushi also worries that some HIVers will fail to note that the Swiss announcement came with some very important caveats. In order for infection risk to be eliminated, the HIV-positive partner must have no other sexually transmitted diseases -- and must have maintained an undetectable viral load for at least six months. Additionally, the negative partner must also be free of sexually transmitted diseases.

“Who really knows for sure that their partners have no STDs?” he asks. “How many of us know for sure that we don’t?”

Similarly, it’s not possible to be certain that one’s viral load is undetectable at the moment of sexual contact, warns John Newmeyer, Ph.D., an epidemiologist at San Francisco’s Haight Ashbury Free Clinic. “You can still have a viral spike from time to time,” he says. “There’s no way of knowing if your viral load test from three weeks ago is still relevant today.”

There’s also no way of knowing from a blood test whether you have detectable virus in your genital fluids. “My HIV specialist says it’s possible to have high viral loads in genital secretions at the same time you have undetectable virus in your blood,” warns Lewis, who believes she was infected with HIV through unprotected sex. “If you’re having sex without condoms, it’s those fluids that pose the transmission risks.”

And just because you may not be exposing your partner to HIV doesn’t mean condomless sex is risk-free, adds Santa Clarita, Calif., HIVer Jayson Stonne: HIV-positive men and women could be putting themselves at risk for a host of other STDs or even superinfection from a different HIV strain.

In light of the many unanswered questions raised by the Swiss commission’s announcement and the many variables that affect HIV transmission risks, it would be dangerous to advocate unprotected sex, concludes Howard. “We at the New Jersey Women and AIDS Network will continue to stress using a barrier during sex to prevent transmitting or acquiring HIV,” she says. “It’s far too early, and there’s far more research that still needs to be done to do otherwise.” 

Tags: Health