Hiv testing

[Ml10]

Hello,

I had unprotected vaginal sex with a female friend who resulted to be hiv negative on a 4th generation test 21 days after we had sex, here are my questions :

1. initially I had two tests at 28 and 30 days after risk exposure, the lab told that me that they were 4th generation tests, the brand was Roche and they used reactives with cobas 600 by chemilumiscence. Can this tests considered conclusive ?

2. At 63 days after risk I had the same 4th generation test with negative result. By this time the antigen p24 can be reached ? If not can I be 100% sure that the antibody part of the test is 100% conclusive ?

I just want to put this episode behind me and start a family.

[H. Hunter Handsfield, M.D.]

Yes, that's a standard, reliable test.

That's all for this thread.  Move on!

[Ml10]

Thanks doctor, The lab Told me The ñame of The test, its an "eclia roche cobas" , eclia tests are reliable tests ?

[H. Hunter Handsfield, M.D.]

Have you STILL not read the threads linked above?  Read the first one (1704700).  If you continue to ask me to repeat answers that have already been given, the entire thread will be deleted without further comment.

[Ml10]

Doc,

One lást question, a third generation test could be considered 100% conclusive at 9 weeks ?

[Ml10]

Thanks

[H. Hunter Handsfield, M.D.]

You misunderstand that test; your question is nonsense.  A negative result means that it is negative for both antibody and antigen, which proves you do not have HIV.  

Disregard everything you think you know about the time to reliable antibody testing.  The combination of negative antibody AND antigen is 100% reliable any time 4 or more weeks after exposure.  That's because the two results are not independent of one another.  It is the antibody that clears p24 antigen from the blood.  At 4+ weeks after exposure, everyone with HIV always has antibody, antigen, or both in the blood.  There are no exceptions.

Perhaps you didn't read or did not understand the discussion in the other threads linked above (maybe English isn't your primary language?).  

OK?

[Ml10]

If I only went for a 4th generation test at 63 days, this will still be 100% reliable for the antibody part only ?

[H. Hunter Handsfield, M.D.]

Welcome to the forum.  Thanks for your question.

The standard tests, including the 4th gen ("duo", "combi") HIV tests, are extremely accurate, so you can be sure your partner wasn't infected.  Once you knew of her result, there really was no reason for you to be tested -- although this might have made sense based on other risks in the past.

In any case, your test results at 28 and 30 days were 100% reliable, even if your partner had had HIV, and there certainly was no need for the third test at 63 days.  If the test is negative, it is 100% certain that neither HIV antibody nor p24 antigen is present.  Your negative results are definitive.

For more detailed information about HIV test reliability at various times after exposure, see these discussions:

http://www.medhelp.org/posts/show/1704700
http://www.medhelp.org/posts/show/1855891
http://www.medhelp.org/posts/show/1891685

So you can definitely "put this episode behind" you, have a committed sexual relationship, and start a family.  No need to worry about HIV.

Best wishes and happy holidays--  HHH, MD