Thanks a lot for all of this Doctor. Much appreciated and enjoy the weekend.
(Amazing job you and Dr. Hook do on this site).
1) Six weeks should be fine for all the syphilis tests.
2) Correct.
3,4) You found some misinformation about urine testing. All the research on urine chlamydia or gonorrhea testing was done randomly through the day, and there is no evidence that the first day's void, or that holding urine more than a few minutes, makes any difference in test reliability. And no reason to suspect underlying kidney disease or urine volume have any effect.
Morning Doctor,
Thank you very, very much for the above responses. You've no idea how much stress they're relieved as I fell into the trap of trawling the net and tieing myself in knots. I have a couple of follow ups if you don't mind, I have searched your site for answers you may have given to others but couldn't find any so hopefully you're responses will be useful for other users in future:
1. Re. the conclusive Syphillis test, is the 6 week mark the definitive time no matter what blood testing was done - I don't know what the NHS would have used and from my research I understand there are several different tests - eg. EIA, IgC, IgM, RPR
2. The risk of HBV from any single exposure would be 'very low' even if the individual had HBV?
3. I've read that urine tests for the standard STIs (ghonnoreah, chlaymdia etc) are most accurate with a 'First Void of the day' sample. However, I have a very active bladder and really struggle to hold my urine through the night. Is there any measurable difference in accuracy between holding your urine for 8 hours or just 3. eg. If I last urinated at 6am before my urine test at 9am?
4. Finally, linked to the above, i go pass urine much more than is normal and have done for years. Something I need to get checked out by a Doctor. I just wanted to check that any Non-STI related infection or kidney problem would not hav any detrimental impact on an STI test detecting an STI ?
Once again, thank you for your advice and thanks in advance to these last queries.
Welcome to the forum. Thanks for your question, and for reading other threads for preliminary answers to your questions.
1,2) The duo tests are definitive any time more than 4 weeks after the last possible exposure, regardless of high or low the risk was, like anal vs vaginal exposure, or a scratch. Your negative result is conclusive.
3) As used to be common for HIV, lots of experts recommend an HBV antibody test at 3 months, even if an earlier antigen test is negative. The odds of HBV transmission during any single exposure are very low; combining that fact with your negative antigen test at 8 weeks, it is exceedingly unlikely you were infected. My personal professional advice is that you could safely forego the 3 month antibody test -- but you'll have to decide whether you'd like to do it anyway, since it's apparently the advice you have had at the GUM clinic (assuming that's where you picked up on the NHS recommendations).
4) Syphilis is extremely unlikely if you didn't have an obvious penile sore (the chancre) -- but in any case, 6 weeks is the time for definitive blood testing. Your negative 8 week test is conclusive.
5) Yes, you can be confident you didn't acquire NGU (same thing as NSU, just different terminologies on opposite sides of the pond).
I hope this has been helpful. Best wishes-- HHH, MD