ZONE:

Performing oral sex on a man carries very low risk of HIV transmission, according to a small study presented August 14 at the National HIV Prevention Conference in Atlanta, GA. However, the possibility of infection cannot be ruled out, the study authors warned.

"I want to emphasize that, while rare, acquiring HIV infection orally is possible and that many other sexually transmitted diseases (STDs) such as gonorrhea, chlamydia and syphilis are transmitted orally," said Kimberly Page Shafer, Ph.D., M.P.H., the study's principal investigator.

Researchers from the Center for AIDS Prevention Studies at the University of California, San Francisco (UCSF) recruited 198 participants, 98 percent of whom were male, from anonymous HIV testing and counseling sites around San Francisco, CA. All participants identified as gay or bisexual and reported no anal or vaginal sex and no injection drug use within six months prior to the study. During this time period, however, almost all the men reported performing oral sex on another man without a condom, and 20 percent reported performing oral sex on an HIV-positive male partner. Of this 20 percent, 89 percent did not use a condom, and 40 percent swallowed ejaculate. All participants underwent HIV testing, including a test that detected only HIV infections that occurred within the six months prior to the study.

Out of 198 men, one HIV infection was reported, but this infection occurred before the six-month study period in which the men exclusively had oral sex, according to the study. Therefore, it was impossible for the researchers to conclude that this infection did, in fact, result from oral sex alone.

"You can't draw global conclusions about the safety of oral sex from a six-month study," cautioned Dr Susan Ball, HIV specialist and associate medical director of GayHealth.com. "Yes, the HIV risk from oral sex is very low, but in the face of other studies, no clinician is going to say this study proves that oral sex is safe."
One such study, conducted by the Public Health Laboratory Service in the United Kingdom (UK), found that oral sex may account for three to eight percent of all HIV infections among men who have sex with men in the US and the UK.

Certain factors do increase the risk of HIV transmission through oral sex, Dr Ball added. "Whenever there is a break in the normal skin or mucous membrane -- if you have a sore in your mouth or recent dental work was done -- it puts you at increased risk for HIV," as do lesions associated with STDs, she explained. Long-term studies are needed to better grasp the actual HIV risk that oral sex poses, she said.

Dr Shafer's study, funded by the US National Institute of Dental and Craniofacial Research, is ongoing, and findings will be updated as more participants are recruited and analyzed.