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4th generation test after 2weeks

Hi I've read that the 4th generation combo test. Which detects p24 hiv1 and hiv2.  are sensitive and can detect early as 14 days after exposure. And I've read many that side 4weeks. So I'm very confused. I tested NEGATIVE after 2 weeks is this a good thing or will it not tell me anything by than. I plan on testing again but just wanted to see if that's a good thing being negative at 2weeks.
5 Responses
370181 tn?1595629445
First of all, what was your risk? For us to accurately assess if you need to test, we need this information.
The vast majority of people do not produce detectable antibodies at 2 weeks, so it is no surprise your test was negative. To detect the virus earlier than 4 weeks requires a DNA PCR test which looks for the virus itself, rather than the antibodies your body produces to fight the infection. Taking a 4th generation DUO test 28 days post your exposure will give you a good indication of your status, but it will not be 100% conclusive until 12 weeks.   Given that the 4th Generation test is very accurate and is relied upon by many HIV specialist, we suggest you rely on it for your results.
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Just uprotected vaginal no ejaculation. And the guy says he is hiv negative so unknown status
Avatar universal
Also, the viral load may drop to an undetectable level upon full sero-conversion.
This is because the body’s immune system may have suppressed the infection to a point where there is not enough HIV virus in the blood for the RNA PCR test to detect.
3. Between day 14 to day 20, the HIV P24 Antigen will start appearing in the blood. This can be detected with 4th Generation tests (aka Combo tests).
This is why, although the official recommended Window Period for the Combo Test is 28 days, we are very confident when a patient tests negative at 2 weeks.
Remember that the P24 Antigen level will peak at about day 28 and becomes undetectable at about 6 weeks from infection.
This does NOT mean the 4th Generation (Combo) test is inaccurate after 6 weeks because the Combo test also detects IgM and IgG Antibodies (See below).
1 Comments
Hi Jenna. When you say we are very confident, do you work for a sexual health centre? Thanks for your answer btw.
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Avatar universal
The 4th generation combo (DUO, Ab/Ag whatever you want to call it) test also looks for p24 antigens which are detectable before antibodies.  So even if you aren't producing antibodies, p24 antigens would still be present for the first few weeks before antibodies begin to develop. From what I've read they tend to BEGIN to show up between 10 - 14 days post exposure if the individual is indeed infected, and then peak/plateau for a few weeks before declining as antibodies are produced. The PCR test can detect even earlier since it looks for viral RNA.  Sometimes these are used for confirmatory tests after a positive 4th gen or positive antibody. Usually at 4 weeks with a 4th gen test you will be ok and can rest easy if you got a negative result.  If you really want peace of mind retest at either 8 weeks with a 4th gen or 12 weeks with an antibody test.  After that, if you had a negative result, don't worry about further testing, you'll just drive yourself nuts!
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366749 tn?1544695265
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