[Question #4505] Late seroconversion, please help

27 months ago
Hello doctors,

I need your immediate help as I'm very worried from what I read on the internet, I had a risk 5 months ago, I had a small cut on my finger and I held the hand of a woman, I don't know if there was blood on the woman's hand, I held her hand while walking together. 
I did a 4th generation test in a laboratory, and it came out negative, but I'm scared because I read an article about rare cases of late seroconversions for more than a year, so what should I do?
My questions:
1- Is my test conclusive at 5 months post exposure?
2-Can the P24 detection part from 4th generation test tell if there is late seroconversion or not? I mean let's suppose that there are no antibodies detected after 5 months, will the p24 antigen part be positive in case of infection? 

Thanks
H. Hunter Handsfield, MD
H. Hunter Handsfield, MD
27 months ago
Welcome back to the forum. Thanks for holding off for a long time on questions about your HIV phobia.

But this is the same kind of question. There is never a risk of HIV by skin contact, including holding hands with an HIV infected person, even if either person has a cut on the hand. You should not have been tested for HIV on account of this event.

Delayed seroconversion might have happened with older HIV tests (first or second generation), no longer in use. Even then, it was extremely rare. To my knowledge, it does not occur at all with the new (third and fourth generation) tests now used for almost all HIV testing.

Therefore:

1) Yes, your test is conclusive.

2) Yes, you correctly understand how the antigen-antibody (4th generation) HIV tests work. p24 Ag is detectable in blood starting about 10-14 days after infection. Antibody then develops. If for some reason antibody were not produced, the test would continue to be positive because of persisting antigen. This is the reason delayed test positivity is impossible with the AgAb tests.

Best wishes--  HHH, MD

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