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Is ICMA HIV Test A Fourth Generation HIV Test?

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Posted on Wed, 17 Sep 2014
Question: Is a hiv abs icma test a 4th gen and is it a duo test? It say This test uses recombinant antigen sources and detects antibodies by specific immune binding and subsequent chemiluminescent reaction (ICMA technology). Sensitivity and specificity of this assay are 100% and 99.9%, respectively.
doctor
Answered by Dr. Matin Ahmad Khan (1 hour later)
Brief Answer:
ICMA a 4th generation test

Detailed Answer:
Welcome to the forum. I am Dr Matin A Khan , answering your question.

The ICMA refers to the method of the test for antibodies to HIV. It is an abbreviation for Chemiluminscent Microparticle Immuno Assay (CMIA) HIV test and yes, it is also known as the DUO test or the 4th Generation EIA test. It looks for both the antibodies and the P24 protein antigens.

The HIV DUO test relies on the principle that when HIV first establishes itself in the body it will start to replicate rapidly and almost as a by-product of this replication a core protein - the HIV p24 antigen - is produced in huge amounts from around 10 days or so after first infection and before or during the time when antibodies to HIV are being formed. The p24 antigen will then stay at a very high level for the first few months after infection and later decline in line with the decline in HIV viral load as referred to above. It will though never completely disappear and will run a variable course of detection through the rest of the illness.
So in general, p24 antigen is formed slightly before antibodies are forming allowing us to close the gap between infection to detection time - the HIV window period. As time goes on, then the majority of newly infected HIV positive people will form antibodies to HIV 1 or 2 by 28 days. In combination then, looking for both the HIV 1 p24 antigen and also HIV 1 and 2 antibodies will allow for much earlier detection of HIV than looking for HIV antibodies alone.
Hope this helps.

Above answer was peer-reviewed by : Dr. Vinay Bhardwaj
doctor
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Follow up: Dr. Matin Ahmad Khan (47 minutes later)
Thank you Dr. for answering my question that was very detailed and very very helpful I also have one more question for you. This test done at six weeks along with a rna PCR test and again at 10.5 weeks with out a rna test. Would these test be considered conclusive i was the receptive of oral sex "male"
doctor
Answered by Dr. Matin Ahmad Khan (49 minutes later)
Brief Answer:
HIV RNA PCR not approved or recommended

Detailed Answer:
Thanks for the query.
I guess your tests have done without following any protocol.
Let us talk about little bit about HIV RNA-PCR Test before answering your questions directly.
This is also called Viral Load (VL) test , done for a new infection. Viral loads can reach very high levels within a few weeks of infection.
They are useful in specific circumstances, usually after a very high risk or traumatic risk, especially if several symptoms suggest seroconversion.
In the presence of symptoms, a negative viral load test is useful. It can rule out HIV because symptoms caused by HIV seroconversion would by definition need viral load to be both high and detectable.
A negative viral load test can reduce initial anxiety and worry until an HIV antigen test can confirm there is no infection.
After infection, viral load is usually very high within the first 1–2 weeks, and so this test can be used to confirm a suspected early infection.
In adults, viral load tests look for RNA and are only usually done when there is both:
a) a history of recent high risk exposure (ie condom break with a known HIV-positive partner); and
b) symptoms consistent with HIV seroconversion (fever, extreme tiredness, heavy ‘flu-like illness etc).

NOW ANSWERS TO YOUR QUESTIONS:
At 6 weeks and 10.5 weeks , it is not possible to answer with certainty. What we know is this that 4th generation HIV antigen/ antibody tests ( ICMA) will detect 95% of infections after 28 days and 99.5% cases by 90 days.
Viral load tests (HIV RNA PCR ) are neither approved or recommended for routine to be done only for the people who just want to test more quickly than the four weeks and are recommended to be done along with an antigen/antibody test. They are less accurate (actual infections can easily be missed), more expensive and require more complicated laboratory technology.
Presuming that your last 2 tests were negative(non-reactive ), at those periods of time, still you have to go for a confirmatory test at 90 days as per protocol.
Since you have not mentioned about the results of your two tests(negative/positive), I can't comment more than this.
Oral sex is a low risk activity for acquisition of HIV in comparison to vaginal or anal sex and being receptive partner in oral sexual activity puts you at a higher degree of risk of HIV than the insertive partner and low risk is not a zero risk.

Hope this helps.


Above answer was peer-reviewed by : Dr. Raju A.T
doctor
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Follow up: Dr. Matin Ahmad Khan (33 minutes later)
Yes thank you and also the test were all negative! I am actually going today for my three month check. Have you ever seen a 10 1/2 weeks change from negative to positive
doctor
Answered by Dr. Matin Ahmad Khan (8 hours later)
Brief Answer:
Thanks and best of luck

Detailed Answer:
Thanks for sharing the information about the previous results.
I have not come across any such case .
Stay safe and keep healthy .
Note: Get personalized answers to your HIV related queries You can choose to talk face to face with your doctor. Book a Video Call now.

Above answer was peer-reviewed by : Dr. Shanthi.E
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Answered by
Dr.
Dr. Matin Ahmad Khan

HIV AIDS Specialist

Practicing since :1987

Answered : 298 Questions

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Is ICMA HIV Test A Fourth Generation HIV Test?

Brief Answer: ICMA a 4th generation test Detailed Answer: Welcome to the forum. I am Dr Matin A Khan , answering your question. The ICMA refers to the method of the test for antibodies to HIV. It is an abbreviation for Chemiluminscent Microparticle Immuno Assay (CMIA) HIV test and yes, it is also known as the DUO test or the 4th Generation EIA test. It looks for both the antibodies and the P24 protein antigens. The HIV DUO test relies on the principle that when HIV first establishes itself in the body it will start to replicate rapidly and almost as a by-product of this replication a core protein - the HIV p24 antigen - is produced in huge amounts from around 10 days or so after first infection and before or during the time when antibodies to HIV are being formed. The p24 antigen will then stay at a very high level for the first few months after infection and later decline in line with the decline in HIV viral load as referred to above. It will though never completely disappear and will run a variable course of detection through the rest of the illness. So in general, p24 antigen is formed slightly before antibodies are forming allowing us to close the gap between infection to detection time - the HIV window period. As time goes on, then the majority of newly infected HIV positive people will form antibodies to HIV 1 or 2 by 28 days. In combination then, looking for both the HIV 1 p24 antigen and also HIV 1 and 2 antibodies will allow for much earlier detection of HIV than looking for HIV antibodies alone. Hope this helps.