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HIV ELISA Ab/Ag CMIA 4th Gen

Question: 

Is there any case where Elisa Ag/Ag detect HIV negative at 3 months, but afterwards turned to positive?

Answer: 

Hi there, thanks for contacting the AIDS Vancouver helpline with your HIV related questions and concerns. We're happy to help!

Here in Canada, the current guidelines for HIV tests is that they're all conclusive at 3 months post exposure. There are a few exceptions to this rule, and in these circumstances, there is further testing conducted until 6 months post exposure. The exceptions are:

1) If you're on antiviral treatment for Hepatitis C

2) If you're being treated for cancer (such as with chemotherapy)

3) If you're on PEP/PREP for HIV

4) If you have an immunodeficiency disease (you would know as they're usually diagnosed in childhood and are serious conditions).

The reason that these 4 cases require further testing is that they cause an immunosuppression in the body, which may result in delayed production of the antibodies.

In terms of the 4th generation combo test that you're talking about, although it's still considered to be conclusive at 3 months in Canada, most HIV specialists in the world have now concluded that this test is actually conclusive at 6 weeks. This is a very effective test!

So overall, except for those 4 cases where I outlined, there shouldn't be any need for further testing (i.e. shouldn't be any false negatives) past the 3 month window period.

I hope this helped! Please refer to our website or avert.org for more information about HIV and testing!

I hope this helped!

Sincerely,

Christina

AIDS Vancouver Helpline/Online
Monday-Friday 9am-5pm (PST)
1 844 INFO-HIV (Toll free Canada & U.S.)
helpline@aidsvancouver.org
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