I am a 47 y/o gay male. Had one brief, unprotected anal receptive sexual encounter with another male who identified being on PrEP. The incident happened on April 27, 2023 of this year and was my only sexual encounter this year. 

I had the following testing follow ups and are curious if I can stop testing.

May 22, 2023- I went to Quest Labs and have an HIV RNA/ Qualitative as well as a 4th Generation test- both "non-reactive"

May 30, 2023- Had another 4th Generation test along with syphilis- both "non-reactive"

June 7, 2023- "Insti" finger prick test [believe it was a 3rd Generation Test]  was also "non-reactive"

June 14, 2023- Quest Diagnostics 4th Generation Test- "non reactive"

June 26, 2023- Alere Determine [I believe was a 4th Generation ab/ag finger prick rapid] along with a Syphilis "rapid" test [did not know they offered these until the person offered it to me].  Both were "non-reactive".

I am unsure if I need to test again at the 12 week mark, as suggested on most forums. Just curious.

On a side note, I was on 7 Day antibiotic from April 29-May 6 called Docxycycline for an upper respiratory infection- not sure if syphilis would have been aborted taking this medication 2 days after the incident. I completed the 7 days according to my sinus regime.

Thanks for any imput.

There was no ejaculation and the penetration was for about 10 minutes...so pre seminal fluids is my concern.

He claimed he was on PreP.  I am looking into PreP before any future sexual possibilities...but my liver enzymes were higher due to doing Keto regime and will have to have another metabolic panel before I start PreP.

You don't need to be told that unprotected anal with another male is high risk for HIV, and receptive anal is the highest risk of all sexual practices. However, your partner being on PrEP dramatically lowered the risk. But at this point, the level of risk at the time of exposure doesn't really matter, because your test results prove you do not have HIV. The earliest tests were reassuring, but not definitive, but the negative results June 14 and 26 were beyond the 45 days that marks conclusive negative results with the AgAb (4th generation) HIV blood tests. That standard indeed applies regardless of the level of risk when exposed. Although many agencies still recommend testing at three months, it really isn't necessary for the AgAb tests, and CDC endorses the evidence for 45 days (which on this forum we often round off to 6 weeks, since 3 additional days makes no significant difference). Your follow-up comment, with implied uncertainty that your partner really was on PrEP, doesn't matter since risk at exposure is no longer an issue.

As for other STDs, your negative syphilis blood tests are conclusive as well; for sure you don't have syphilis. In addition, doxycycline would have aborted syphilis if you were exposed, so there's double security you don't have it. I would have recommended anal testing for gonorrhea and chlamydia quite a while ago. Those tests are valid any time 4-5 days or more after exposure. Good plan to do that now. You could skip the chlamydia test: there is no possibility of still having it if you ever did; doxycycline is 100% effective. However, doxycycline isn't reliable against gonorrhea, and in almost all labs chlamydia testing is automatic when gonorrhea is tested. You can expect negative results for both.

I endorse your plan to start PrEP. But even with PrEP, condoms would be a good idea -- a lot less important for HIV protection, because PrEP is so effective, but you don't want other STDs either! That said, in the event you expect to continue condomless anal sex, either insertive or protective, you should speak with your doctor about possible doxycycline prophylaxis to prevent syphilis and, secondarily, chlamydia plus partial protection against gonorrhea. It's just a single 200 mg dose before or within a couple days after sex. This strategy, called Doxy-PrEP, has recently proved highly effective especially against syphilis and chlamydia, and official CDC guidance on it is expected within the next few weeks. Most HIV-knowledgeable physicians and clinics are aware of doxy-prep and already are prescribing it.

So almost certainly all is well. Go ahead with the anal gonorrhea (and chlamydia test), but you don't need any further tests for either HIV or syphilis. Go ahead with HIV PrEP and discuss doxy-prep with your doctor.

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

HHH, MD

I don't follow your comments about syphilis; I didn't say you have or ever had it. Negative RPR is solid proof against current syphilis but does not rule out past syphilis. You don't mention the newer EIA syphilis test. If done and negative, it excludes both current and past syphilis.

Indeed MSM are the population group at maximum risk of syphilis in the US, but that does not dictate HIV testing (by AgAb test) more than 45 days after a potential exposure. The combination of negative tests you describe (AgAb ~4 weeks plus RNA 3 weeks also is conclusive. You really didn't need any further tests after you had those results even though most experts would still advise a final AgAb test after 6 weeks. 

Thanks for your comment about one of my books. I imagine you're referring to AIDS Dx/Rx, way back in 1990. And thanks for your kind comments about ASHA. (Maybe consider a tax deductible donation!)

Thanks for your answer with this scenario.

Ill put forth a donation towards ASHA. 

Thanks for the thanks and especially for your planned donation to ASHA! Best wishes and stay safe.