[Question #4266] HIV and Syphillis

32 months ago

Hi Dr’s,

 

Just wondering what the likelihood of a 5 week negative Syphillis test (blood from arm) has of turning positive at a later date? Here in England most advice seems to suggest 3 months!! Is that ultra conservative and what are the chances percentage wise that my test will turn positive?

 

Likewise for an HIV duo test at 6 weeks!

 

I’ve just retested at 11 weeks and I’m terrified that either will turn positive! Help!!

 

Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
Welcome to the Forum.  I'll be glad to comment. You do not say much about the exposure that has led you to test.  In most situations however, if a syphilis blood test is going to become positive after an exposure, it will typically do so by five weeks after the exposure.  The same is true for HIV and at 6 weeks, HIV tests are absolutely conclusive.  The recommendations you received for re-testing are overly conservative.  I am confident that your 11 week tests will also be negative.  Please don't worry.  EWH
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32 months ago
Hi Dr,

Thanks for the reassuring advice! 

So I can pretty much assume I’m not at risk and to fully expect a negative result?

My risk was oral (receiving and giving) anal fingering and rimming (received only) and then very briefly I inserted into another mans anus without a condom but this was no more than a minute! 

Can I ask why so many authorities still recommend 12 weeks for Syphillis when your advice clearly suggests this is not the case? What percentage of accuracy would my 5 week test be? 

Glad to hear my HIV test is conclusive at 6 weeks! I thought it might be after various research suggesting the same thing but I think I have a very overly conservative healthcare advisor! 
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
The recommendation for 12 weeks for syphilis tests to become positive reflects a combination of conservatism by those who feel they cannot afford to ever be wrong and information which is old and out of date.  Because syphilis is hard to study, older statements made years ago continue to be repeated despite the fact that our knowledge and understanding of the disease has progressed. 
EWH

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32 months ago
Thanks Dr, so I’m right in assuming if these tests come back negative as you suggest, I should consider this conclusive and move on? 

Percentage wise, how accurate was the 5 week result? Based on my experience is there anything else I should test for? I’ve had a full STI panel at 1 week and 5 weeks too and everything thus far has been negative! 
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
Yes, please consider the test results you are waiting for conclusive. 

At 5 weeks your HIV result was more than 99.9% accurate.  As for syphilis, there are fewer high quality data but my estimate is that the five week results are also at least 99% accurate.  I have never seen or heard of an instance for either infection in which a result changed after 5 weeks.

This is my 3rd reply to your questions.  As per Forum guidelines, this thread will be closed later today without futher responses.  Take care and please don't worry.  EWH
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