I had an encounter with a guy which involved making out and both receptive and insertive oral sex without ejaculation on either part, but there was precum. He told me afterward that he was HIV+, but taking Atripla, and that his viral load was undetectable. Like many people, he believed that oral sex carried no risk of transmission. I tested negative at five months and felt relieved, but now doubts are creeping in again. Would you recommend a retest?

Hello.

Oral sex carries only a very low risk for HIV transmission/acquisition. If your buddy was indeed on effective antiretroviral therapy that drove his HIV plasma viral load to undetectable levels, this would significantly further reduce your already low HIV-transmission risk. The CDC recommends testing out to the six-month mark for significant HIV exposures. If you want that level of certainty, retest at six months. I'm extremely confident the result would once again be negative. Most HIVers have detectable levels of anti-HIV antibodies in their blood within four to six weeks following HIV primary infection. Consequently your negative HIV-antibody tests out to five months are extremely encouraging. I see no reason for "creeping doubts " and would recommend a crescendo-ing WOO-HOO instead. Okay?

Be well.

Dr. Bob