I’m positive and would love to get head from my negative partner. How safe is oral sex in mixed-status couples—and what role does gender play?            

 —Oral Lover

Dear Oral Lover,

Is HIV infection through oral sex possible? Yes. Is it probable? No. Whatever your gender is, it’s difficult to calculate exact risk, because most people who’ve seroconverted have engaged in additional behaviors. Penile oral-infection cases have been documented for both performers and recipients. While a 1998 Montreal study described the risk for performing oral sex as “small but not negligible,” a Sydney, Australia, study reported no infections.

Cunnilingus holds some risk if a positive woman’s vaginal fluid or blood enters a partner’s open oral wound. A woman receiving cunnilingus is at risk only if blood from her positive partner encounters cuts or sores in or around the vagina. Rimming, or analingus, isn’t problematic for HIV—but risks hepatitis and parasites.    

The likelihood of transmission increases if your negative partner has bleeding gums or cuts from recent brushing, flossing or dental work—even cuts, sores or blisters around the mouth can be risky if blood or genital fluids reach them.

Although precum contains virus, levels are low, and research shows low blood viral load reduces virus in genital fluids. Saliva contains protective enzymes that can destroy HIV, but it’s not 100% effective. If you plan to have oral sex, avoid drugs and alcohol—both dry the mouth. Swallowing ejaculate is not recommended. Tears or acid-reflux burns in your throat or esophagus increase the likelihood of transmission.

If you avoid oral sex immediately after brushing or flossing and have no cuts or irritation in or around the mouth, the risk is almost negligible.

+ Perry N. Halkitis, PhD, is a professor at New York University and Director of the Center for Health, Identity, Behavior & Prevention Studies.

Got a question for our sexpert? E-mail it to sexpert@poz.com.