Syphilis Testing Question

Hello Doctor,
              I have a brief question regarding the testing window for Syphilis as the information out there is rather vague.  Last October I had a brief unprotected sexual encounter with a young woman who I believe is rather promiscuous.  The condom slipped and exposure was about 4 mins.  To be on the safe side, I had an STD panel done at three weeks, all returning negative, including Syphilis (which was the RPR test).  My negative HIV ELISA was received after 3-months.  I felt great, but have been recently reading varying opinions about the validity of a Syphilis RPR before the 3-month mark.  I can't find a solid reputable source that is definitive.  I should note that I haven't had any symptoms that would indicate Syphilis, but I like to be on the safe side.  Your expertise would be greatly appreciated.  Thanks much, and kudos to a job well-done out here!  I have much respect for your patience with the patients!

[Edward W Hook, MD]

Welcome to our Forum. I'll be happy to provide some information.  First however, let's consider your risk in context.  Your risk of syphilis is very low. Syphilis is a rare STD and over 60% of syphilis occurring in the U.S. occurs among men who have sex with other men, hence your risk of infection is low.

By three weeks after exposure any person who was going to develop a lesion would have done so but not all persons would have a positive blood test (half or so, perhaps a bit more would have).  At 3 months a syphilis blood test would be definitive.

My guess is that you did not get syphilis,  Your risk is very low, you did not develop a lesion at the site of exposure (and would have noticed is you look at yourself at all) and you had a negative blood test at a time when many but not all persons with syphilis would have positive tests. Taken together, my advice would be to not worry about syphilis however if you want to be 100% ( as opposed to 99%) sure that you did not get syphilis, you should have another test. Personally, I would not worry and would not seek further testing but that, of course, is up to you. EWH

[sethmo1300]

Your thoughtful and reassuring response is very much appreciated.  I figured as much, but needed a trustworthy opinion.  Perhaps at my next annual checkup I'll ask my PCP to do a definitive test, but I won't worry in the meantime.  Again, Doc, much appreciated.  Best Wishes to you.

[Edward W Hook, MD]

Glad to help.EWH