Avatar universal

Syphilis false positive or not

35M Europe - Confusing (false positive) Syphilis (update)

I performed oral on a guy 5,5 weeks ago.
His penis looked clean, he didnt cum or no lessions were seen.

I did a full std check at 23 days (I know too early)
Hiv, chlam and gon negative (penile and oral)

Syphilis undecided:

ECLIA: 1.24 (>1.0 =positive ) (Roche);

Igg blot = negative;

Igm blot = indeterminate;

  Tp15m = detected, others not;

VDRL = not done (hemolytic sample);

Hemolytic sample;

Sample was collected through fingerprick self+ milking finger to collect blood (could explain hemolytic)
(To be mentioned I had confirmed influenza and high fever on the say of sample)

I have no ulcers nor any symptoms.

I did a retest 2 weeks later (5 weeks past incident)

ECLIA: 0.1 (>1.0 =positive )(Roche)

No other test done due to negative sample.
Sample was collected by Doctor thru vein.

How to interpret the results?
False positive or else?

Is it adviced to retest at 12 weeks?
1 Responses
Sort by: Helpful Oldest Newest
207091 tn?1337709493
It sounds like a false positive. Did they do any confirmatory testing?

I'm not sure what this means:

Tp15m = detected, others not

I can't find this test. It's not an STI test.

Your IgM indeterminate - ignore it if that's a herpes test. It's a highly unreliable test, and shouldn't have been done. If you have concerns about herpes at 12 weeks, get another IgG test, but otherwise, you can skip it.

Helpful - 0
No these are all Syphilis tests

Igg and igm immunoblot tests.
If 1 antibody is found (this case tp15m antibody), the result of the test is ‘weak’ or ‘unclear’ (neither positive or negative)
Oh got it. Those aren't tests usually done in the US.

Anyway, since your 2nd test was negative, I'd say your first was a false positive, possibly because of the flu, though that's a guess. Most often, we don't know why false positives happen.

I'd test again at 90 days. Your risk is pretty low - oral sex is lower than vaginal or anal sex, and syphilis is less common than gonorrhea or chlamydia. I wouldn't worry, but just to be sure, a test will be conclusive at 90 days.
Have an Answer?

You are reading content posted in the STDs / STIs Community

Didn't find the answer you were looking for?
Ask a question
Popular Resources
Herpes spreads by oral, vaginal and anal sex.
Herpes sores blister, then burst, scab and heal.
STIs are the most common cause of genital sores.
Millions of people are diagnosed with STDs in the U.S. each year.
STDs can't be transmitted by casual contact, like hugging or touching.
Syphilis is an STD that is transmitted by oral, genital and anal sex.