HIV risk

I am a male and had a sexual encounter with another male.  I do not know his HIV status.  We were standing up and I was behind him rubbing my erect penis between the top of his glutes.  He reached around and directed my penis towards the top of his legs - closer to his anus.  I gently thrust 3 or 4 times and the tip of my penis came into contact with his anus.  I may have penetrated him slightly, but I don't think so.  I was not wearing a condom.  I'm not entirely sure if this factors into the situation, but I am not circumcised.

What is the risk of HIV transmission?

[H. Hunter Handsfield, M.D.]

Welcome to the HIV forum.  The bottom line (no pun intended) is that there is little or no risk of HIV transmission from this sort of contact.

One analysis by CDC calculates that the average risk of HIV transmission from unprotected anal sex, from the anal (bottom) to the penile (top) partner, is around 1 transmission for every 500 exposures.  That assumes the bottom partner is infected, and it also is considered to apply to several minutes of sex until ejaculation.  Further, one reason anal sex is particularly high risk is that the lining of the rectum is easily injured, with blood exposure during sex.  Simple skin-to-skin contact in the anal area, or exposure of the penile opening to the outside of the anus, probably carries no risk.  I don't see that your circumcision status makes any difference; being uncircumcised increases HIV risk by about double, but only if the exposure itself carries substantial risk to start with.  Finally, not knowing your partner's HIV status, we can take an educate guess at about a 10% chance -- i.e., even those odds are strongly in your favor.

For these reasons, I cannot imagine there was sufficient exposure to put you at risk.  I don't recommend HIV testing in this sort of circumstance.  However, you certainly could do that (with an HIV antibody test after about 6 weeks) if this reassurance isn't sufficient and you'll sleep better knowing the negative result.

If and when similar situations arise in the future, you need to ask your potential partner his HIV status before getting involved, and avoid going forward (or for sure avoid unprotected anal sex) with those who say they are positive, don't know, or who seem evasive in their replies.  Yes people can lie and some can be infected but not know it -- but usually such information is reliable.  In the long run, this "do ask, do tell" approach is just as important for safe sex among men having sex with men as condom use for anal sex.

I hope this helps.  Best wishes--  HHH, MD