insertive v. receptive oral

[punker77]

Dear Doctors,
I recently had unprotected fellatio performed on me by a person of unknown status although they did say they were HIV negative. It was performed to completion with me ejaculating in the person's mouth. I have read many prior post of similar experiences and understand the risk involved. My questions are as follows: Is the zero risk consistent for both insertive and receptive participants? Does ejaculation make the urethra more susceptible as a route of transmission?  In addition, would blood visible or not visible play a role in the risk for the receptive partner as a potential route through the urethra or would open wounds on the penis need to be present and subsequently change the zero risk? Lastly, is testing warranted from a medical perspective or simply something to ease anxiety? I thank you kindly in advance for your reply.

[H. Hunter Handsfield, M.D.]

Welcome back to the forum. Thanks for your question.

It partly duplicates parts of the question you asked back in 2008, when Dr. Hook discussed the low risks for oral sex -- although the main concern then was cunnilingus (oral-vaginal contact).  The data on oral sex exposures have not changed significantly since then.  However, we have not summarized the issues recently in any single reply, so I'm taking the time for a blog-like response that replies to these questions and can be used in future replies to similar ones.

To my knowledge, there are no reported cases of HIV being transmitted by cunnilingus, in either direction.  It can safely be considered a zero risk practice for both the oral and vaginal partner.

For fellatio, there are a few reports in which it seems likely the receptive (oral) partner was infected.  A few men have reported that they believe they caught HIV by being the insertive (penile) partner in fellatio, but most experts believe there are no proved cases of such transmission and many consider it a truly zero risk activity.

An analysis several years ago by CDC came up with estimates that the average risk for the receptive (oral) partner in fellatio (without a condom) is around 1 in 10,000, and for the insertive (penile) partner around 1 in 20,000 -- if the other partner is known to have HIV.  These rates are equivalent to giving or receiving unprotected fellatio by infected partners once daily for 27 and 55 years, respectively, before transmission might be likely.  Here is a link to the data source:

http://www.cdc.gov/mmwr/PDF/rr/rr5402.pdf

The available data do not account for ejaculation in the mouth (arguably higher risk for the oral partner, but probably no effect for the penile partner), duration of the exposure, presence of blood or gum inflammation or other wounds, circumcision status, other concurrent STDs, the stage of infection or treatment of the partner with HIV, and other factors.  However, given the extremely low risk for oral sex in general, it is fair to assume that these have little impact.  For example, if a particular factor doubles the risk of transmission and the rate therefore rises from 1 in 20,000 to 1 in 10,000 exposure events, does it really make any realistic difference?  Logically, probably not.

So having had a single episode of insertive oral sex, with a partner who probably does not have HIV, I would rate your risk of infection from that event as zero and definitely not something to warrant HIV testing -- unless, as you suggest, so the negative result will help ease your anxiety about the event.

I hope this has been helpful.  Best regards--  HHH, MD

[H. Hunter Handsfield, M.D.]

Thanks for the kind words.  I'm glad to have helped.

[punker77]

Thank you ever so much for the informative reply.
Regards.