I later had laboratory tests: RPR at 3, 9, 10, 12, and 16 months. TPAB x2 at 15 months. TPHA at 16 months. ALL NEGATIVE. Supplements, 150 mcg biotin were paused before TPHA. I have never received syphilis treatment. 

1. How significant is the rapid test brand, and do their faint positives hold diagnostic weight given later lab results?

2. Is my 3-month RPR sufficient to rule out infection, despite the faint positive rapid test?

3. Considering all lab results, is further testing needed to conclusively prove I was never infected in the first place? 

Thanks so much!

I’m not sure why you’re back.  Your questions have been answered by our prior responses and repeating them is not going to change the answers.  Further, your testing history is a great example of the hazards of overtesting.   Brief answers:

1.  You are overreading the rapid test results.  STOP the rapid tests!!! Your RPR and TPHA are the results to be believed.

2.  YES,YES, YES!!!

3.  You’ve been told the is no need for further testing.  That answer is not going to change.

A final comment.  Your fixation on syphilis is not serving you well.  The best advice I can provide you is to strongly encourage you to seek counseling about how to address the anxiety and, I would guess, guilt over your dalliance nearly two years ago.  I say this out of concern for you, nothing more.  EWH

Protected sex with my wife on May 4 and May 19. My wife later also tested RPR negative at 9 months (no TPHA was done for her).

On May 10, my wife developed itchy, broken skin on her leg. She was prescribed Amoxicillin 625mg( 1 tablet twice daily, total 6 tablets from May 13-16) and a topical cream, cured in few days. I used her cream for my existing skin problem, but am fairly certain I did not take any of her Amoxicillin as I had no symptoms.

1. However, if I hypothetically had taken only 2-3 tablets of her Amoxicillin day 14- 16 post exposure, could that have cured a very early syphilis?

2. If I had infected her on May 4, would her course of Amoxicillin (May 13-16) have coincidentally cured that infection?

3. Could the Amoxicillin she took have prevented an infection from our protected encounter on May 19?

4. Could the very faint grey positive rapid tests at 11 weeks post exposure indicate I was infected, and the negative RPR at 13 weeks(3 months) means I was "cured" by the hypothetical Amoxicillin?

There is a difference between the amount of penicillin/amoxicillin that it takes to prevent syphilis (I.e. stop development of syphilis before lesions or positive blood tests are present) and to cure lesion or blood test positive syphilis.  Further syphilis cannot be acquired in the absence of contact with infectious lesions which you’ve never had.

Responses to your “what if” questions:

1.  Yes, it could have prevented syphilis from occurring.

2.  Yes, if you had syphilis ( you didn’t) , the amoxicillin could have prevented acquisition of infection.

3.  Yes

4.  No, see my earlier response 

My advice remains for you to seek confide professional counseling for your totally unwarranted, likely guilt driven anxiety.  EWH

I've now thought it over and I'm sure I didn't take any amoxicillin, so the earlier hypothetical worries don't apply anymore. Just few last points.

1. Although you cannot see my rapid tests, could you share your general view on very faint grey lines on home tests- are they typically evaporation lines or simple false-positive reactions?

2. If I had been your patient from the beginning and reported faint rapid test lines at 11 weeks, what advice or next steps would you have given me?

3. Even knowing about those faint line, what makes you confident I do not and have not had syphilis?

4. In my unique case--- with only one lifetime exposure --- does my negative 3-month RPR effectively mean I've never been infected at any time in my life? （No matter how high risk of the exposure）

5. And do my 15-16 month negative TPAB/TPHA confirm that I have never had syphilis in my lifetime?

6. There's no risk of me transmitting anything to my wife or a future baby, correct?

Thanks again! I'll do my best to move on. 

1. They reflect over reading of  evaporation lines on your part, particularly if they were looked at after the recommended time.

2.  My recommendation for you or anyone else in your situation is to stop worrying and move on. Believe the laboratory based tests.

3.  Once again, you do not have syphilis. Believe your multiple laboratory test results.

4. Yes

5. Yes

6. Correct.

This completes this question which will now be closed.  The best advice I can provide you is found at the end of my initial response to these questions, PLEASE seek counseling, for your own sake.  EWH