I need to know the accuracy of 4th generation EIA method with blood draw ? I took it exactly after 49 days (7 weeks). It was negative after 1 week of waiting for results. the clinic said these tests are accurate after 11 days. ( i know CDC and many experts say 28 days to 6 weeks)

I got tested at 77days with a rapid 4th generation test and a Clear View rapid test. I got tested because i felt little sick and i doubted my results. But they were negative as well.

Finally, i got tested at 90 days for conclusive results with a Insti rapid test. It was negative.

Today its been 1 month after my last test
& 4 months after a minor incident. So i started worrying about my tests again.

Can you verify if my results are correct and the tests taken were correct in terms of their accuracy and window period ? thanks
Hi there, and thanks for contacting the AIDS Vancouver Helpline with your HIV/AIDS related health information. You seem concerned about the accuracy of some tests you've had. We're happy to answer your questions.

In summary, you've had a 4th generation test 7 weeks post exposure, another 4th generation test after 77 days, and a RAPID test 90 days post exposure. To start, here is a bit of information on the tests you've had:

You'll see that in the chart, the 4th generation test is officially considered conclusive (here in British Columbia) at 3 months post exposure. So the two 4th generation tests you had at 7 weeks and 77 days were very good indicators of your status, but were not considered conclusive. The RAPID test you had at 90 days, however, is considered conclusive. You do not require any further testing.

Thanks a lot for contacting the AIDS Vancouver Helpline with your question. We hope we answered it fully.


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Test Name Method Window Period Conditions
4th Generation EIA Blood test that looks for antibodies AND p24 protein antigens. Commonly referred to as the "combination," "combo" or "DUO" test. P24 protein is detectable immediately after infection but only for the first few weeks. The antibody (ab) test has a window period of 4-12 weeks post exposure. This test is widely available in North America. Most HIV specialists consider this test to be conclusive at 6 weeks but official HIV testing guidelines still recommend re-testing at 12 weeks for conclusive results. Conclusive at 3 months post exposure.
Rapid or “Point-of-Care” Blood or oral swab test that looks for antibodies. Up to 95% of infections are detectable within 4-6 weeks post exposure. Most people develop detectable antibodies in 21-25 days. The rapid test is a type of 3rd Generation test. Two forms available: finger prick blood sample or oral swab. Oral swab test is most common in the U.S. but due to false positives in Canada it is not approved and blood collection is more likely. Many places in the U.S. and abroad may charge a fee for rapid testing. Conclusive at 3 months post exposure.