[Question #13793] Syphilis Test Window

 
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16 days ago
In Nov 2025 I received unprotected oral sex from a female in a massage parlour.
Shortly after I began to worry about my exposure to an STI.
Although I saw no symptoms I finally went for a test 9 weeks after the event.
They all came back as negative -  gonorrhoea chlamydia HIV and syphilis,
I still worried about the syphilis result.
It was an EIA blood test but the NHS in UK say it is only conclusive after 12 weeks.
However on finding your site I see that 6 weeks is seen as conclusive..

Am I worrying for no reason now.?  I have just met someone new and hope to start a relationship but I’m avoiding sex of any sort. In fact I’ve had no sexual interaction since the oral sex in November.
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Edward W. Hook M.D.
16 days ago
Welcome to our Forum.  Thanks for your questions.  I'll be glad to comment.  Let me start by reminding you that the exposure you describe was low risk- most commercial sex workers do NOT have syphilis (or other STIs) and even when partners are infected, most single exposures do not lead to infection.  Syphilis following receipt of oral sex is quite rare and the absence of any symptoms on your part is further evidence that you were not infected (on average the primary syphilis lesion or chancre appears within 3 weeks of acquistion of infection.  

Official bodies such as the NHS and US CDC tend to be conservative- overly so, often based on data that are decades old.  if a syphilis blood test has not turned positive within 6 weeks of an exposure it is not going to.  I urge you not to worry.  I really see no need for further testing however, if you choose to test, I am confident that that test will also be negative, proving once again that you were not infected..  In the interim, I see no reason to start a relationship with a new partner.  EWH
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12 days ago
With 12 weeks now passed - and being a natural worrier - I went for a final test today. Coupled with the direct advice from yourself and similar answers on this site, I anticipate a negative result. 

I asked the nurse about the window period and she said while she was aware of the lower figure they stuck with 12 weeks.
 
At the levels yourself and Dr Handsfield operate, do you know if anything active is being done to clarify this window information across the board?
It would certainly help reduce a lot of worry for many. 

Many thanks for the work you do.