[Question #5418] Syphilis exposure - initial positive

21 months ago
Hello, 
Need some advice (I am a male).  I recently tested positive on initial screening for Syphilis.  Specifically on CLIA test.  I was told that the RPR and TPPA were also done and were negative.  I was advised to go for another test to confirm as it could possibly be false-positive.  My exposure was unprotected oral sex and protected vaginal sex with csw on May 9th from Germany.   I tested for std's on May 15th

The reason I went in for testing is because I was feeling urethral discomfort.  Doctor game me zithromycin as precaution.  I tested negative for Chlamydia and Gonorrhea.

I tested again at 2 week mark but know it can take up to 6 weeks.  Should I be looking out for chancre sore and how soon would it appear if infected?  It has been 16 days post exposure as of today. 

Would the zitrhomycin I took as precaution have any affect on possible early syphilis infection? 
 
What are the odds that it was indeed a false-positive (which I hope is the case).
21 months ago
Also - I'm married and don't want to infect my wife if I indeed have syphilis.  It's difficult coming up with excuses until window time has passed.  What are the chances of her getting nfected in the absence of me not having a chancre yet, assuming I'm infected?
Edward W. Hook M.D.
Edward W. Hook M.D.
21 months ago
Welcome to the Forum.  I'll be glad to comment.  It appears that you have a false positive screening test for syphilis.  The exposure you describe was low risk,  syphilis is a rare disease and most CSWs in Germany do not have STIs, including syphilis, particularly if your exposure was in a licensed brothel.  Further, syphilis following oral sex is very, very rare and your genital exposure was condom protected.  Thus based on the nature of your exposures, your risk for syphilis is very, very low.  

The azithromycin you took clouds the issue.  If you took it within a few days of your exposure it may have worked to prevent syphilis if you had been exposed. OTOH, if taken more than a week or two after your exposure, it may have delayed your test becoming positive.  When did you take the azithromycin and what was the dose?

Finally, it appears that your syphilis screening test was either falsely positive.  If you truly had syphilis, the RPR and TPPA performed after the positive CLIA test should have been positive.  On occasion, the CLIA test may become positive slightly before the RPR and TPPA however the other tests typically become positive just a few days after the CLIA test becomes positive.  If you retest for syphilis at this time and get similar results, you can be confident that your positive CLIA test was falsely positive.

Sorry for the complexity of this response but, particularly having taken the azithromycin, that's the situation.  I would test again, as I said.  The results at his time will be reliable.  EWH
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21 months ago
Thank you Dr. Hook for your response and expertise. 

I was given a single dose of azythromicin at an std clinic for the urethral discomfort.   I think 500mg as the pills were marked at 250mg each.  There was white blood cells on the gram swab.  Here are exact dates for clarity :

8th May - unprotected oral exposure 

11th May - urethral discomfort starts 

15th May - return to US.  Go to std clinic for testing.  Found wbc on swab.  Given azythromicin.  Test for hiv/gono/chlamydia and syphilis. 

20th May - negative on all stds with exception of clia syphilis positive.  Rpr and ttpa negative. 

22nd May - retest only rpr and negative at <. 76

Is it to soon for rpr to show up any infection?  I had unprotected sex with my wife yesterday and now scared she is in danger.  I kept putting her off.  Would the absence of symptoms be in our favor?  I don't want to keep having sex if it is and would have to let her know, which most likely end our marriage. 

Thanks for all you do. 

Edward W. Hook M.D.
Edward W. Hook M.D.
21 months ago
Your test on 5/22 was too early to be helpful in sorting things out.  If you retest on or beyond Monday the 27th and you RPR and TPPA are again negative, you can be confident that your original screening test was falsely positive.  At that time you can move forward without continuing concern.  EWH---
21 months ago
Thanks Dr. Hook. 

I will test again first week of June and accept the results as conclusive whatever it may be. 

One more question.  Let's assume I'm in the seroconversion stage and have yet to produce enough antibodies and no symptoms.  As stated, I had unprotected sex with my wife prior to getting the positive clia result.  Was she at risk even if I have not yet showed symptoms (ie. Chancre sore)?  I will abstain from sex until I get the definitive result. 

Edward W. Hook M.D.
Edward W. Hook M.D.
21 months ago
I think your strategy for testing the first week in June is an appropriate one.  Again, please remember, if you really have syphilis, you should have positive tests by more than just one type of test (i.e. the RPR, TPPA and CLIA should all be positive).

Regarding transmissibility, syphilis is transmitted by DIRECT lesion contact.  No lesion, no transmission. Thus I would not be overly worried that you might have transmitted to your wife.  Further, I think it is most unlikely that you will find that you have syphilis.  

This will complete this thread which will be closed shortly without further responses. Take care.  EWH
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21 months ago
Thanks again for your responses and expertise.  Take care.