[Question #325] Syphilis Testing

105 months ago

With concern about a possible STD exposure in Sept. 2012 (hand to genital contact with a few female

massage providers), I had an STD panel completed in Jan. 2013. All results were negative, including the

syphilis RPR. I had not observed any symptoms of primary or secondary syphilis. Since that time I have

been plagued by prostatitis, eye floaters and tinnitus. Knowing that some experts recommended a

confirmatory test first, I had an FTA-ABS done by a national laboratory testing service in Aug. 2014

(patient ordered). The FTA-ABS was equivocal. My physician ordered a FTA-TPPA from a well known

clinic / lab in Minnesota. That result was negative. I subsequently ordered another FTA-ABS in May

2015 and got another equivocal result. WHAT SHOULD I DO? Still plagued by prostatitis, eye floaters

and tinnitus. Additionally, I started having significant cervical spine joint problems (pain, joint cracking

and grinding). BTW, I am a 60 year old male.

H. Hunter Handsfield, MD

105 months ago

Greetings and welcome to the forum. Thanks for your question.

The bottom line is that you do not have syphilis, needn't be worried about it, and shouldn't have any more tersts for it. There are several reasons.

First, there is no realistic chance of syphilis or any other STD from hand-genital contact. Second, in North America, the frequency of heterosexually transmitted syphilis is extremely low; it's a rare disease even in the most active commercial sex workers, and there is no reason to be suspicious of it in female massage workers. (The large majority of syphilis in the US is in gay men.) Third, in the off chance somehow you were infected, probably you would have had a syphilitic ulcer (the chancre) of your penis, i.e. at a point of hand-genital friction. Its absence was strong evidence you weren't infected with syphilis. Fourth, your symptoms are not suggestive of syphilis. While it is conceivable that tinnitus could be a symptom, this would be very rare as the main manifestation; and neither prostatitis, ocular "floaters", nor spin cracking/grinding are at all suggestive. (The last suggests garden variety osteoarthritis of the spine, exceedingly common in people your age.) Finally, a negative RPR more than 6-8 weeks after exposure is conclusive evidence against syphilis. The RPR sometimes becomes negative over time in people with untreated syphilis. But that's over many years, never before a year or two.

It isn't really true that "some experts recommend a confirmatory test" in a situation like this -- at least not most true syphilis experts. If you were under the care of a doctor who genuinely suspected neurosyphilis (i.e. infection of the central nervous system, which could cause tinnitus), then you are correct that confirmatory testing would have been recommended. However, that situation -- active neurosyphilis only 4 months after exposure -- would never have a negative RPR. Accordingly, you should have stopped while you were ahead! The FTA-ABS test is well known to give occasional equivocal or weakly false positive results. But once that was done, it was proper to do yet another confirmatory type test, and the T. pallidum partical agglutination test (TPPA, not "FTA-TPPA") fit the bill. That negative result confirmed you don't have syphilis, and the next FTA-ABS after that is simply reflected the previous false result.

The only other consideration is that once in a while, equivocal or weakly positive FTA-ABS results are due to antoimmune disorders, especially systemic lupus erythematosus (SLE). It can also be a side effect of certain medications. This is uncommon, and none of your symptoms suggests lupus to me. But this gets outside my primary area of expertise; it's something to discuss with your doctor. I stress that the large majority of the time, no underlying cause if found and no harm results. Obviously, though, you should avoid having any future FTA-ABS tests; the false result probably won't change.

For those reasons, you can be confident you don't have syphilis. I suggest no further testing and that you move on without any worry about it.

I hope this has been helpful. Best wishes and happy holidays-- HHH, MD

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105 months ago

Dear Dr. Handsfield, MD:

Thank you for your informed response. Besides helping me, I hope that this dialogue saves others from the needless expenditure of time, money and worry. I believe that you have definitively answered my questions, but to recap for other readers these were my sticking points: 1. With regards to disease transmission, the phrase, “skin to skin contact” was probably the most disturbing. Additionally, the possibility of acquiring the disease by “touching a lesion”, led me to believe that anything was possible with syphilis. 2. The medical literature was lacking with regards to making sense of equivocal test results (i.e. what do you do with multiple equivocal results using the same testing methodology). 3. Is FTA-ABS really the “gold standard”? Could the autoimmune process that gave me pernicious anemia also interfere with this test? My provider really didn’t want to talk about it. 4. Is the reverse algorithm for syphilis testing really better than the traditional testing cascade? The big question: Have I done enough to protect my spouse from the consequences of my actions? Thank you again for your help.

H. Hunter Handsfield, MD

105 months ago

Happy to clarify things further.

1) "Skin to skin" and "touching lesion" are partly true, but they mean that any skin-skin contact is risky. Your partner would have to have an infectious syphilis lesion on the hand or fingers -- and syphilis lesions on dry skin almost never are infectious.

2) As in your case, multiple equivocal results (with the same test) don't mean anything in regard to syphilis. What one does is that you did and I implied in my answer: have one or more other tests using different technology.

3) There is no single "gold standard" test for syphilis. Diagnosis generally depends on a combination of exposure history, clinical manifestations, and test results -- and always a combination of test results if one is positive. I'm not up to speed on current understanding of pernicious anemia and its causes. But I believe the answer is yes: it seems possible your equivocal FTA-ABS result is related to that diagnosis.

4) The "reverse algorithm" for syphilis testing wasn't apparently used in your situation. Most experts would describe it as different than the traditional test sequence, with each having their advantages and disadvantages depending on the clinical situation, lab facilities available, and testing in settings with low or high background prevalence of syphilis.

5) You have done more than enough to protect your wife. In addition to ruling out active syphilis, the RPR is 100% conclusive in excluding infectious syphilis, i.e. cases that can be transmitted to partners. Even leaving aside the zero chance of transmission and the evidence you don't have syphilis at all, the negative RPR in January meant that even if somehow you were infected, it was not transmissible to your wife.

Cheers-- HHH, MD

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H. Hunter Handsfield, MD

105 months ago

Answer no. 1: "...but they DON'T mean that any skin-skin contact is risky." Sorry for the typo.

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104 months ago

Is the RPR test sensitive in late latent or Tertiary Syphilis?

H. Hunter Handsfield, MD

104 months ago

RPR occasionally misses late latent syphilis, but is highly sensitive for tertiary syphilis. It is rare to have active (non latent) syphilis with negative RPR. But that doesn't change anything in my previous replies. I suggest you re-read them very carefully, word by word; they explain why you definitely do not have syphilis and should stop worrying about it. It's time for you to move on.

That completes the alotted two follow-up comments and replies and so ends this thread. Best wishes.

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