I went to a party on 11/8 and had drunk unprotected sex with someone. The next day they texted me and said they are a trans woman (I did not know as it was dark and quick). They also said we had anal (I inserted). They tested negative for STD panel 10/31 but had protected sex 2 weeks before that test. What is my risk, especially HIV?

Although this could have been a high risk exposure, you don't provide very much information about your trans partner except that she had receptive anal sex with two different men in two weeks. That certainly could imply an inherently risky lifestyle. On the other hand, people rarely lie about HIV or STD status when asked directly, so it is fair to assume she indeed tested negative about a week before your exposure, and was not exposed again after that. Undoubtedly those tests included HIV, so almost certainly she doesn't have it. The same can be assumed about syphilis, i.e. that she had a negative blood test. The next question on my mind, though, is whether her tests included rectal swabs or only urine for gonorrhea and chlamydia. You might want to check with her on that. But if those tests were done, you can also be confident she didn't have either one of them.

Also remember that even if she had HIV, the risk the virus is transmitted during any single episode of unprotected anal sex is around one chance in a thousand. Considering all these issues, I would put the chance you acquired HIV at well under one chance in a million and the chance of syphilis also in that ballpark. Chlamydia and gonorrhea are a lot more common, so the risk is higher. However, absence of typical symptoms (penile discharge, painful urination) at 4 days is by itself nearly 100% assurance you don't have gonorrhea. Chlamydia conceivably is possible but it's zero if her recents tests included rectal testing.

Considering all these issues, your risk for HIV is extremely low, probably zero. I certainly would not advice post-exposure prophylaxis with anti-HIV drugs, or to prevent bacterial STDs. Even testing for STDs is optional; I would advise it only if you feel you would like the reassurance you would gain from negative tests results. If so, you can have a valid urine test for gonorrhea and chlamydia at any time (more than 4 days after exposure) and blood tests for syphilis and HIV at 6 weeks. Alternatively, if you're in touch with her, consider offering an opportunity for the two of you both to be tested for all these. Maybe you'd even find she's as worried about infection from you as you are from her, and would appreciate the reassurance. With all negative results, you'll both know neither could have infected the other.

I hope these commetns are helpful. Let me know if anything isn't clear.

HHH, MD

Thank you for your reply, I appreciate the reassurance. 

She sent me screenshots of her tests which included HIV, syphilis, chlamydia and gonorrhea.  What concerns me is that she had sex 2 weeks before the test was taken and thus may have been in a window period since she took a 4th gen HIV test. She did say she used a condom with that person but I am still concerned.  If I were to take a RNA PCR HIV test at the 11 day mark after the incident would that rule out the possibility of contracting HIV from this encounter? I worry she may have acute HIV if she acquired it from the sex she had 2 weeks before her test on 10/31. 

 

As many on this website seem to be, I am a highly anxious person. I respect your research and background from University of Washington greatly. I think this situation just totally shocked me because I have never had anything like this happen before.  Trying to research through the internet can be overwhelming.  I am still on the fence about the RNA test since the results can be had sooner but am leaning more toward just standard test at 6 weeks. I respect your advice and will get tested purely for reassurance but otherwise put this episode behind me. Thank you so much. 

Second, let's calculate your actual risk. If we guess a 10% chance her previous partner has untreated HIV and the transmission risk for a single exposure, her risk of being infected was around one in 10,000. If she had been infected, 2 weeks later there's a 50% chance her 4th gen test would have been positive. Now we're at 1 in 20,000. With the transmission risk to you also around 1 in a thousand, the chance you were infected calculates to 1 in 20 million. To put that in context, for the average US resident the National Safety Council calculates the odds of dying in the next 12 months of an accident (falls, fires, auto wrecks, etc) at 1 in 1,756. That's nearly 12,000 times higher than the chance you have HIV. 

So my advice, only slightly tongue in cheek, is to not worry about HIV -- but don't forget your seatbelt and get off the golf course during during thunderstorms! 

Now that literally made me laugh out loud.  I feel much better after receiving your advice. Dr. Hook and yourself offer a truly great service through this site. Thank you so much!