[Question #8633] Positive RPR

41 months ago

Hello again. Against your wishes I went and got tested once more at 6 months. This time my RPR came back reactive with a titer of 1:1 H according to my results from quest. The confirmatory FTA-ABS test came back non reactive. They told me this was a negative test. However the county health department is calling me asking about my reactive rpr and now I'm scared. Could I have syphilis? I took this test a week after I came down with covid. Could that have caused the reactive rpr?

H. Hunter Handsfield, MD

41 months ago

You do not have syphilis. You have what in the STD business is called a biological false positive syphilis test result (BFP). This is quite common, occurring in 1-2% of all RPR or VDRL tests. The negative FTA-ABS is proof you do not have syphilis. It's hard to say why the local health department is in touch. Perhaps they started the process before having the FTA-ABS result. But I suggest you return their call; probably they will repeat this same reassurance.

You may be onto something with your question about COVID and BFP syphilis testing. COVID vaccination for sure does this; there's been an official FDA warning about it (https://www.cdc.gov/std/fda-alert-12-20-2021.pdf). I am unaware of reports of COVID19 itself doing this, but other inflammatory conditions can cause BFP and I imagine COVID could do so.

That STD tests aren't perfect is one reason I and Dr. Hook advise against testing when there is no risk. You've had an unnecessarily anxiety producing outcome as a result. But now you might want to find a doctor to follow up, perhaps with repeat RPR. Most BFPs clear up on their own, with no health consequences. But if persistently false positive, then future syphilis testing should be with an EIA (i.e. IgG/IgM) blood test rather than RPR.

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41 months ago

So there is no reason to test again? The health department said they were going to follow up with the lab who administered the test to ensure they performed it correctly. Thanks for answering my question. I understand now that I do not have syphilis. Thanks for your help

H. Hunter Handsfield, MD

41 months ago

If you have had previous negative RPRs, you can safely assume the current BFP is transient (maybe due to COVID?) and won't happen again. But to be certain, you could have another RPR in a few months, in the hope it would be negative. It's up to you.---

41 months ago

So what would be my reason for testing again? Just to see if I get another BFP or am I checking for syphilis? I really do not want to get tested again. Is this enough evidence for a syphilis free diagnosis. This uncertainty is scoring me. I did all of this to make sure I gave nothing to my pregnant wife.

41 months ago

I guess the real question is with all the testing I've done. 3 rprs at 2 weeks, 4.5 weeks and 11 weeks. All non reactive. And this one at 6 months that is reactive but confirmatory testing is non reactive. With this information can I say with 100 percent certainty that I do not have syphilis? And would further testing be only to check and see if I still have BFPs or is it to check if I have syphilis?

41 months ago

Is there any reason to track down the cause of this bfp? Or can I safely ignore it? I know I'm asking another of questions.

H. Hunter Handsfield, MD

41 months ago

Yes, it is certain you do not have syphilis. I already told you the reason to consider another RPR: "If you have had previous negative RPRs, you can safely assume the current BFP is transient (maybe due to COVID?) and won't happen again. But to be certain, you could have another RPR in a few months, in the hope it would be negative." In other words, you would learn whether or not you have a persistent BFP. If you do, future syphilis testing should be with an EIA test, not RPR. If no continued BFP, then RPR would be valid testing in the future.

That concludes this thread. I hope the discussion has been helpful. Best wishes and stay safe.

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