4 weeks are enough for false positive re testing

I heard a lot of people got false positive result and I didn't expect I will have one of the false positive result.
I didn't have any exposure for the last year and last month I went to one the BARs and two customers where having a fight their and unfortunately I interfered to separate them,  but I got hit by one of the knifes with a small cut in my hand ( very minor with no bleeding but scratch ) next day I was worried and I did HIV test, the doctor performed rapid test and came Positive then he took another blood sample to perform 2nb test it was COMBO HIV 1&2 AB/AN Serum test and he told me this is very reliable test and after 4 hours he told me it came negative but to be 100 % sure about the result he requested me to come back after 4 weeks as if the their is a real HIV antibodies in my blood as 4 weeks is  a good time  to have a clear picture.
Yesterday I went to him as I already completed the 4 weeks and he did anther HIV Rapid test and it was negative.


a-Do you think my body was so quick to make antibodies that is why I got positive result next day by  using the quick test if this is the case, why the 2nd test didn’t discover the antibodies ( combo test did cost me 100 USD)?

b-Do you think 4 weeks are enough for my body to  produce a good number antibodies to be found by the test  to see if I really got infected? or should I wait for another 24 weeks or 6 months?

c-My first result was COMBO HIV 1&2 AB/AN Serum 0.338 and 2n d one was rapid test Negative HIV 1 & 2 do you think performing 2nd rapid test is conclusive or should I go for another type of test ( honestly Rapid test is only 20 USD but the combo is 100 UDS) ?

d- two week ago I had a strong headache plus I didn't feel comfortable around my neck area ( like I’m facing a difficulties when I'm swelling my salvia for 2 weeks, is this ARS symptoms plus the doctor told me their some lymph node around your neck but I didn't have cold fever or temp!

[kenzorio]

Even if you had become infected in the way you describe (which is itself unlikely since, while you got a cut, where not exposed to any blood - and even if you had been, that blood would have to be infected itself. And even then it seems like an unlikely mode of transmission), it is highly unlikely the rapid test would be able to pick it up after 1 day. I don't have any references on this but since people usually test negative while having ARS symptoms (which is 2-4 wks after infection) it seems common sense that it is unlikely to test positive after 1 day. Even more so when considering the minimal viral load there could be at this time and the biological implausbility of antibodies being generated so fast.

It's a very good sign the combo test was negative since the combo tests are usually thought to be both more sensitive and specific than the rapid test. The rapid tests have more false positives than the combo test, in fact 1 out of 200 negative people will test false positive on some of the rapid tests. Since the combo test should be more sensitive than the rapid test, and since it was just 1 day after potential exposure, it is highly probable it is just a fluke with the rapid test.

Still, do the combo test at 12 weeks to be sure. If you want reassurance before, you can do a combo test at 4 weeks like your doctor suggested since most people will seroconvert in that time but of course there's a cost to all that testing as well. Given the situation I wouldn't want to take any more rapid tests. I read that if the rapid test is false positive it stays that way on repeat testing with rapid tests, at least with the same brand. So repeated testing with rapid tests won't give you any further information.

[Vance2335]

A) No your body did not produce antibodies, false positives happen.
B) 3 months is conclusive
C) Any antibody test at 3 months is conclusive
D) No it is not

Your risk from you described was near zero if not zero.

[kenzorio]

Even if you had become infected in the way you describe (which is itself unlikely since, while you got a cut, where not exposed to any blood - and even if you had been, that blood would have to be infected itself. And even then it seems like an unlikely mode of transmission), it is highly unlikely the rapid test would be able to pick it up after 1 day. I don't have any references on this but since people usually test negative while having ARS symptoms (which is 2-4 wks after infection) it seems common sense that it is unlikely to test positive after 1 day. Even more so when considering the minimal viral load there could be at this time and the biological implausbility of antibodies being generated so fast.

It's a very good sign the combo test was negative since the combo tests are usually thought to be both more sensitive and specific than the rapid test. The rapid tests have more false positives than the combo test, in fact 1 out of 200 negative people will test false positive on some of the rapid tests. Since the combo test should be more sensitive than the rapid test, and since it was just 1 day after potential exposure, it is highly probable it is just a fluke with the rapid test.

Still, do the combo test at 12 weeks to be sure. If you want reassurance before, you can do a combo test at 4 weeks like your doctor suggested since most people will seroconvert in that time but of course there's a cost to all that testing as well. Given the situation I wouldn't want to take any more rapid tests. I read that if the rapid test is false positive it stays that way on repeat testing with rapid tests, at least with the same brand. So repeated testing with rapid tests won't give you any further information.

[kenzorio]

Regarding your answer to c, in the case of a rapid positive test, I don't think it would make sense to use this test again, since even false positives will stay false positive (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC179847/). Of course, he could take the rapid test first. If it is negative now, he's negative. If it's positive, he should take the combo. Personally, I would just skip the rapid test altogether and take the combo.

[falsepositive]

Thanks a lot for your answes, but the doctor did another rapid test yesterday  after 4 weeks of the intial positive by rapid so and he did again using rapid test wich came negative should I consider this as a final or should I re test again today or in the future?

[Vance2335]

What did I write above about a conclusive result?

[kenzorio]

Sorry didn't see the thing about the 2nd test. It's good that it turned negative again but it doesn't nullify the window period.
So if you need to test more  depends on your risk. It's hard to tell what the risk is from the information you have given so far. If there's absolutely no risk there's no reason to test further (and there would be no reason to test in the first place). If there was a risk, you need to wait until the 12 wk mark for a conclusive result but you could get one at the 4 wk mark for reassurance. If you want maximal reassurance at the 4 wk marks you should do the combo, since it is more sensitive in the early part of the window. Then you can use the rapid at the 12 wk mark. If it shows negative, you are negative. If it is positive again, you should retry it with combo.