Risk from Brief Unprotected Insertive Anal 'Dipping'

[chrisk225]

Hi Dr. I am a young male and yesterday I had sex with another young guy who I have known for a little while, but this is the first time we had sex. We mostly just did mututal masturbation and kissed but at  a few points, probably 4 or 5 times, the head of my penis pushed inside his anus slightly but wasnt thrusted. Each time it was inserted, it was never fully and probably lasted for a couple of seconds.

I understand this was stupid, but from reading up on it, it appears that being the insertive partner is lower risk, and I think because this was such a brief period it would be even lower risk also?

That said, I am now concerned, even though he had repeatedly said he is negative and has never had an STI and a had a test a couple of months ago and has not had anal sex since. I have no reason to not believe him, but I do know that sometimes people lie or simply make mistakes and arent aware that they could be positive.

We are both healthy young males in pretty peak physical fitness and have apparently both never had an STI - and I really dont want one.

I am now seriously considering PEP, as it is 26 hours post exposure.. What is your advice on this plus the risk i have placed myself under, considering I cant really force him to go and get tested again.. If I was to start PEP, would it still be as effective if started by around 48 hours post exposure?

THank you.

[Edward W Hook, MD]

Interesting question but one which cannot be answered- sorry.  This has not been studied however, the volume of secretions is likely to be less important than the concentration of virus in those secretions.  These are then modified by issues such as duration of exposure, presence of absence of abrasions, etc.  EWH

[chrisk225]

Hi Doctor, another question if I could: I understand that a number of variables come into play in relation to HIV transmission, but are you able to comment at all on how much fluid, e.g anal mucus or blood, would be required to come in contact with an insertive partners urethral opening/penis mucosal membrane for transmission to occur? Are we talking minute amounts or would significant quantities be required? I'm more interested in anal mucus and your thoughts. Thank you.

[Edward W Hook, MD]

I do not recommend PEP both becuase of PEP's "downside" and the fact that it is both unlikely that your partner had HIV or that if he did, your risk for infection is less than 1%.  EWH

[chrisk225]

Doctor, thank you for the response. I'm not sure if I will be able to get the guy to have a test tomorrow but I had one last week and am negative with no risky history for at least 11.5 weeks before that test.

Do you not recommend PEP because you think it is unlikely that even if he was HIV positive, it would not have transmitted?

[Edward W Hook, MD]

Welcome to the Forum.  I'll try to help.  Risks for HIV are averages and are almost certainly influenced by variables such as the depth or and duration of penetration however there are no studies to allow us to quantify such variation.  

That said, the risk of this encounter is low.  Your partner states that he was tested and found to be negative- he probably is.  Of course he could be wrong but it is unlikely.  Most people do tell the truth.  

You are correct that the insertive partner is at lower risk for infection if the partner is infected than the receptive partner. The risk for infection is 1 in 200 for the insertive partner and 1 in 100 for the receptive partner.

I would not recommend PEP in the situation you describe.  It is expensive and has frequent side effects (less than half of people who start PEP actually finish it.  I understand your concerns however and suggest that you can address them by arranging for your partner (and you, after all, turn around is fair play) to go and get rapid HIV tests done tomorrow.  If they are negative, as I anticipate they will be, there is no realistic reason for further concern.  If you need PEP (which as I said, it quite unlikely), it can be started up to 72 hours following exposure although, as you point out, the earlier it is started the less effective it probably is.  

I hope this is helpful.  EWH