Heterosexual Exposure Female to Male Risk?

[Terrified11]

White male. Today, I had a "one night stand" consisting of unprotected insertive vaginal sex, and unprotected cunnilingus with a white female of unknown status.

She reports having no sexual infections, but I have no independent verification of that. I am aware that she was (indeed as reckless as I was in) willing to have unprotected sex, and I reckon she's had other such one night stand encounters before.

She is, by her own reporting, not an IV drug user although she uses other "light" drugs recreationally (marijuana, etc.), and had several tattoos. Not that one can ever really know by appearance alone, but she appeared "robust" and healthy.

I am circumcised and have no visible cuts or wounds on my penis, although I did shave several days earlier.

I am aware that the reported risk of F-M transmission is estimated at 1 in 2000. But I am also of the understand that this figure may be somewhat speculative (to the extent that some homosexual encounters and IV drug users are not comfortable reporting as such).

Based on this data, would you advise PEP? I plan to test beginning at 4 weeks, but to moderate my anxiety in the mean time, I was hoping for some guidance tailored to my facts.

Thank you in advance for any help you can provide.

All the best.

[Terrified11]

Thanks again.

All the best.

[Edward W Hook, MD]

Yes, if her test is negative at this time, for all practical purposes you really were not at any ris. EWH

[Terrified11]

Thank you Dr Hook.

After discussing the matter with my partner, she went to complete an oral rapid swab test. The result was non reactive. Assuming no exposure within the window period, is this test reasonably accurate in assessing her status?

[Edward W Hook, MD]

Welcome to the Forum. I'll try to help.  The data estimating that, IF you were exposed to a female partner who had HIV, your risk for infection would be, on average, between 1 infection/ 1000-2000 sex acts are pretty solid, having been generated by a number of large studies.  This estimate can be adjusted upward or downward depending on things such as whether or not you are circumcised (you are, this lowers your risk), whether or not you have another STI (sounds like you do not, tis too  lowers your risk), etc.  It is however an average figure.

In your own case, your risk is far lower than this as you do not know that your partner had HIV, that she says she does not (most people tell the truth), and that the average frequency of HIV among North American women is less than 1 infection per 10,000 women.    Thus your mathematical risk from this single ill-advised encounter is actually less than 1 in 10 million.  This is not a range where PEP with all of its costs and side effects is recommended.  It is certainly reasonable for you to seek testing, first for other more common STIs such as chlamydia and, after 4-6 weeks, for HIV.  In the interim however, I would urge you not to worry too much, this was a low risk encounter.  

I hope my comments are helpful.  EWH