[Question #4379] HIV testing window periods

32 months ago
Hi,

Quick questions regarding HIV testing window periods:
1) HIV combo done at 47 days post exposure, came back negative.
2) HIV testing  done at 12 weeks (84 days) (not sure which type, could be antibody only or could be combo, let's assume it was antibody only - since it was a public clinic - read on the gov website that some labs still use 3rd gen tests in my province).

 The tests are done on a couple, first one on me, the second one on the girl - new relationship, we recently started dating. Are they both conclusive? 

Regarding the test done on the girl, some sources claim that 3 months is advised, others mention 12 weeks, other say it;s no difference. Dr Handsfield already answered my question saying there is no significant difference, but most labs use combo tests anyway.  Since I found that in my province some labs still use 3rd gen tests  just wanted to ask your opinion if a negative antibody test at 12 weeks (84 days) should be redone at 3 months (90+ days), or not.

I am a little OCD on HIV, so just wanted more education on the topic to allay any anxiety that arises.

Thank you for your help.


Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
I'm sorry you felt the need to return to our site after so recently receiving Dr. Handsfield's statements assuring you that your test results were conclusive.  since you refer to "my province" I presume that you are in Canada.  If so, according to colleagues in Canada, combination HIV antigen/antibody tests have been the standard, routinely used tests by public health clinics and laboratories in Canada for several years.  Thus, it is more likely than not that you were tested with combination, 4th generation tests and have conclusive results.  Put another way and repeating what Dr. Handsfield has already indicated:

1.  Combination HIV antigen/antibody tests provide entirely conclusive results at 6 weeks (42 days) after exposure.
2.  Antibody only tests are absolutely conclusive at 90 days after exposure and there is no significant difference in the reliability of results at 84 vs. 90 days.
3.  Sites which suggest different time windows form statements 1&s above are wrong and overly conservative.  4.  4.  Based on the results noted above, neither you nor your partner need further testing for HIV related you your encounter 47 days prior to testing.

I hope that this information is helpful.  Take care. EWH
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32 months ago
Dr Hook,

Much appreciated the response! So for me no further testing needed, however for my gf if she tested at 84 days instead of 90 days after her last bofriend and I’m not sure what type of test it was, does she need to repeat the test to have it after 90 days(assuming it was antibody only)? I understand most clinics use combo tests, but I don’t know for sure which type was done for her, as on a gov website it states that some labs still use antibody only.

I discussed my OCD with her she understands it and is willing to test again to put my mind at ease.
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
For a scientific perspective, neither you nor your new GF need additional testing at this time, irrespective of what sort of test she might have had.  Obviously, repeat testing to accommodate your OCD is another issue and a personal choice for the two of you.  EWH
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32 months ago
Thanks dr Hook, that's good enough for me. Have a great evening and thank you for your advice and expertise.
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
Great, I am glad I could help.  Take care.  EWH
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32 months ago
Dr Hook, just a last question for educational purposes and future references. On my test results it said non-reactive to HIV-1 p24 antigen, HIV-1 and HIV-2 antibodies. So it doesn't test for HIV-2 antigen, or is it the same for both types? If it doesn't when would one need to take the test to rule out HIV-2 infection (what would be the window period, if it tests for HIV-2 antibodies only, not the HIV-2 antigen)?
Edward W. Hook M.D.
Edward W. Hook M.D.
32 months ago
No, the combination (4th generation) tests do not test for HIV-2 antigen.  This is a minor limitation- HIV-2 is rare with less than 100 our of over 45,000 new cases occurring in North America last year.  HIV-2 occurs primarily in West Africa and parts of India and even there it causes only a minority of cases.  HIV-2 antibody testing performed at more than 8 weeks after exposure is definitive however.  In our experience concerns about HIV-2 amongst our clients is just not warranted.  In your case, I would discount any concerns you might have about HIV-2- your own tests are definitive.  Your or your GF's risk for HIV-2 is less than your risk of being struck by lightening while reading this reply.

This is my 3rd reply to your question, thus as per Forum guidelines this thread will now be closed.  I trust that you will control your OCD and not need to return to the site for further validation of the definitive test results you and your GF have.  Take care.  EWH
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