[Question #5667] Syphillis False Postitive Concerns

73 months ago

Hello Doctor,

While having unprotected veginal sex with a white caucasian girl, I had a cut on my foreskin of the penis. Girl mentioned that she is clean and as long as I am clean there is nothing to worry about. 3.5 weeks after this encounter, I had developed a sore throat, muscle pains which lasted for about a week, my mouth and body were dry, headaches for weeks. I took HIV 4th Gen DUO at Labcorp at 4, 8, 12 and 24 weeks after exposure. I have also taken HIV RNA at 36 and 90 days post exposure. All the results are negative.

On suggestion of my Physician, I took Syphillis RPR test at 6 weeks after exposure. The RPR came out to be positive with 1:2 antibody count detected. However, the supplementary TP-PA and TP- EIA came out to be negative. So my physician suggested to repeat the test after 2 weeks. However, I was given Antibiotics (Cephalexin) to help cure infection caused by cut on my foreskin during the exposure. My first RPR was about 4 weeks after the last time I took antibiotics.

8 weeks after exposure and about 6 weeks after last antibiotics dosage I repeated RPR. The RPR came out to be positive again with 1:2 antibody count detected with TP-PA and TP- EIA being negative. My physician suggested to take one more Syphillis test after 3 months.

13 weeks after exposure and about 11 weeks after last antibiotics dosage I repeated RPR. TThe RPR came out to be positive again with 1:2 antibody count detected with TP-PA and TP- EIA being negative.

Do you think that my Cephalexin cured Syphillis some how or is it just false positive? I am about to start a new relationship and I have repetitive muscle pains accompanied by mild diarrhea, so do you suggest taking penicillin shot just in case?

I got tested for Chlamydia, Gannorea, HEPA, HEPB and HEPC about 6 weeks after encounter. All negative. Repeated HEPC after 12 weeks, Negative again. Should I need to be tested for any other STI’s?

H. Hunter Handsfield, MD

73 months ago

Welcome to the forum. Thanks for your question.

For sure you do not have syphilis. Some people have the issue called "biological false posistive" syphilis tests. That's exactly your situation; you definitely do not have syphilis. With BFP, the standard historical screening tests (the "nontreponemal" tests, like RPR and VDRL) are positive, but all confirmatory tests are negative. BFP is the reason the treponemal tests never are used alone to diagnose syphilis: if positive, confirmatory testing is done to make sure it's syphilis. Your confirmatory tests have been consistently negative and prove you do not have syphilis. In addition, the failure of your RPR to become negative is additional evidence against syphilis.

Your situation is a but more confusing than sometimes, because the problem became apparent after an unsafe sexual encounter. But the repeated test result prove the truth. You do not have syphilis and never did.

BFP sometimes occurs in association with other underlying health problems, such as certain autoimmune diseases, and sometimes as a side effect of certain drugs. You might discuss this with your doctor, just to be safe. But the large majority of people with BFP syphilis tests are entirely healthy and remain so.

I also note your negative test results for HIV and other STDs. All those results are conclusive. However, you don't mention herpes, and might discuss HSV testing with your doctor. I mention it because herpes is the most common cause of otherwise unexplained "cuts" of the penis; and it sounds like you got an infection on top of the cut. This also makes me think of genital herpes. You should disucss this possibility with your doctor.

As for starting sex in your new relationship, I recommend you sort out the herpes question first. But for sure no worries about syphilis, HIV, or any of the other infections for which you were tested.

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

HHH, MD

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73 months ago

Hello Doctor HHH,

Thanks for the reply. This clears up about Syphillis. I was thinking that may be Cephalexin cleared Syphillis.

The cut on the foreskin was caused during the sexual encounter (Phimosis). This was my first sexual encounter. I also got tested for Herpes about 45 days after the exposure. Here are the results:

HSV1 IgG: Negative (<0.91)

HSV2 IgG: Negative (<0.91)

Are these results conclusive?

After 3 RPR tests, specialist mentioned to take Triponemal tests first and reflex it to RPR in future for screening.

I was also mentioned that repetitive RPR may be due to some viral infections like HIV or Hepatitis. With the nature of exposure (Involving injury) and repetitive RPR, I had to take multiple HIV screening tests up to 6 months after the exposure. All of them consistently have been negative.

1. If I have an auto immune disease, will the HIV 4th Gen test at 24 weeks, RNA at 90 days conclusive or do I need to retest?

2. If I have an auto immune disease, will the HEP-C Ab test at 12 weeks and HEP-A Ab, IgM and HEP-B core Ab, IgM at 45 days conclusive or do I need to retest?

3. With all these results can I start a new relationship?

I have been suffering from recurring flu like symptoms like body aches, gastro problems. I have started therepy on suggestion from my physician due to my fear over STI's. But at this point, I have no clue if I have a medical condition or if I'm imagining things.

H. Hunter Handsfield, MD

73 months ago

OK, herpes isn't an issue. Those test results are conclusive.

Your doctor is exactly right: in the event you need future syphilis testing, start with a treponemal test. In fact, that's what most labs do now anyway, so the issue probably won't come up again.

1,2) There are no medical conditions, including autoimmune diseases, that alter the reliability of any of the tests you had, including HIV and all the others.

3) You can resume a new sexual relationship any time you wish. You have nothing you can transmit to a partner. As for having "...if I'm imagining things": Whenever someone suspects his or her own symptoms have a psychological or emotional origin, usually s/he is right. That statement makes me even more confident you have no infection from the sexual exposure described.

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73 months ago

Hello Dr. HHH,

Thank you for the reply.

I have been having recurring knee pains, ulcers in the mouth, abdominal pain, seborrheic dermatitis and loose stools (not diarrhea) for the last 6 months. I agree that some of the above problems may be due to stress and since I have been only observing these for last 6 months I started to look into STD's as explanation.

I have a few questions.

1. Blood tests for HSV1 (IgG), HSV2(IgG), Hep-A (Ab, IgM) and Hep-B (Ab, IgM) are done 7 weeks after exposure. Do I need to retest any of these?

2. Blood test for Hep-C is done after 3 months after exposure. Do I need to retest for Hep-C?

3. Blood test for 4th Gen HIV was last done 6 months after exposure. Do I need to retest for HIV?

4. Is there any other STD test that you recommend?

All the above test results were negative.

Thanks a tonne for you patience Dr. HHH.

H. Hunter Handsfield, MD

73 months ago

All those test results are conclusive and you should not have any more tests for any of them. Your symptoms are not those of any STD and you do not need any more STD testing of any kind. If you continue to have symptoms or you are otherwise concerned, see a doctor. But move on with no worries about HIV or any other STD.

Thanks for the thanks. That comcudes this thread. Take care and stay safe.

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