On the 27th of September I had unprotected insertive anal sex with a man who did not know he was HIV positive. When he told me, I got an RNA and Ab/Ag test done on Day 6 post-exposure, both negative. 

On Day 14, I purchased a PCR RNA Test from STDCheck.com. That night I ended up having a panic attack and went to the ER where they gave me another AB/AG lab test that came out negative. The RNA Test done on Day 14 came back as negative yesterday as well. 

I’ve seen many of your responses regarding RNA tests and being accurate after 11 days and have also noticed a shift in your verbiage when discussing it. Previously you would say it’s 90-95% accurate but needed a 4th gen AB/AG after 4 weeks, but now recently I see you saying it’s conclusive on its own and further testing is not required. Where do you stand on it now? Is my 14 day RNA conclusive? Is another test on Day 28 or 42 needed? Should I still re-test anyway because of the confirmed exposure? Thanks for the response. 

Our advice is not unchanging when new data become available. Other aspects of our advice about HIV testing also have changed significantly over the years. First it was understanding that on rare occasions it takes up to 45 days for the AgAb tests to become positive, at which time we revised our advice about final testing from 28 days to 6 weeks (or 45 days). And you have learned the most recent change along these lines. For most of the past 10-15 years during which HIV RNA PCR ("viral load") has been used for post-exposure testing, there were concerns and a bit of uncertainty about how soon they were considered conclusive, and so our advice about especially high risk HIV exposures (like unprotected anal sex) was for both RNA testing at 10-14 days and AgAb at 4-6 weeks. More recently, a consensus has evolved among HIV testing experts that RNA testing is conclusive after 11 days.

We still often recommend an AgAb test a few weeks later, if only because many anxious persons like the additional reassurance of another negative test result. But in light of current knowledge, we now consider that optional.

For your situation, I will add (as you likely already know) that during even the highest risk of all sexual practices, unprotected anal sex, the average transmission risk is under 1% (1 in 100) for the receptive partner, if the insertive partner has untreated HIV; and around 1 in 900 (rounded off to 0.1%) for the insertive partner in the opposite situation. And since it is probably statistically unlikely your partner was infected, of course your risk was even lower. For these reasons, the odds are strongly against acquiring HIV during any single exposure, i.e. strongly in your favor. At this point, I think you can relax entirely -- but think about whether you'll sleep better if you also have had a negative AgAb test in a few weeks.

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

HHH, MD

Thanks for the response! I do have some clarifying questions/responses I’d like to make, but this is my last response until I take another conclusive test so that this thread can be closed with a solid answer for folks reading in the future. 

To clarify, I know you say the odds are low but I can confirm I did have unprotected anal sex, as the insertive partner, with someone who had acute HIV. I know even then the odds are less than 1%, and with the 14 Day PRC you’re saying is conclusive I can be sure I did not contract it, but just thought I’d clear that up.

Can I ask what led to the change in the consensus among experts? Was it simply a larger sample of consistent, accurate results or did a study come out that led to a change in opinion?

For my peace of mind, does it matter what type of test I use to get a second conclusive result? Could it be either an Ag/Ab test at 4-6 weeks or another RNA test done sooner? 

Thanks for responding, again. It eased my anxiety immensely! I’m ready to put it behind me like you said.

(And although I know it’s redundant, since you basically implied it in your last response, and because science does not deal in absolutes, is there any way you can conpletely put any lingering nerves to rest and say outright my test was conclusive?) 

It seems most logical to rely on a second test type for confirmation, i.e. AgAb rather than RNA/PCR. But there are no data on this.

I don't know how I can say with more certainty that you don't have HIV. Except maybe you'll appreciate knowing that in the 20 years of this and our preceding forum, with thousands of questions from people worried about HIV following possible exposure, nobody has yet reported they tested positive. I'm confident you won't be the first. If and when it happens, surely it will not be with a falsely negative test result!