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HIV CMIA Test Accuracy

Keywords: HIV CMIA, HIV CMIA Window Period, HIV CMIA Method, HIV CMIA Results, HIV CMIA Accuracy

To be able to understand the answer to this question, we first have to get some basics right.

The HIV CMIA test, HIV ELISA test, HIV ECLIA test are all different methods to detect HIV antibodies and/or antigens in the patient’s blood.

I previously wrote an article on the HIV ELISA and ECLIA test.

Let me rehash some points:

To know if a person is infected with HIV or not, we look for HIV antigens or antibodies in the patient’s blood.

Antigens are a part of the protein shell of the virus. This is found floating in the patient’s blood very soon after infection.

Antibodies are produced by the patient’s immune system in response to the HIV infection. It might take some time for the patient to produce enough antibodies to be detectable by tests. This is called the window period.

Antigens and antibodies are microscopic particles. We cannot see them with the naked eye or even with a light microscope.

So scientists have developed very smart ways to let us know if there are antigens and antibodies present or not.

Click on the picture for the latest information on the HIV testing Window Period

Click on the picture for the latest information on the HIV testing Window Period

 

 

 

 

 

 

 

 

 

One method is called ELISA which is short for Enzyme-Linked Immuno-Sorbant Assay.

This is a very elegant test. Basically there is a trap for the antibodies and antigen. If these are present, they get stuck in the trap. This then triggers off a reaction that causes the solution to change colour. The colour change is indication of a positive test.

Another method is called the ECLIA which is short for Electro-Chemiluminescence Immunoassay. In the same way, the system traps antigens and/or antibodies. The difference is instead of triggering off a chemical colour reaction, it lets off light which is captured by a sensor. So basically if it lights up, it means the test is positive.

The HIV CMIA test which is short for Chemiluminescence Microparticle Immunoassay. It is very similar to the ECLIA test because it also uses light to indicate the presence of antibodies and/or antigens.

All the above is obviously a massive over-simplification of a rather complex topic. For those interested in more detailed information, there is a great resource in a learning guide developed by Abbott. Click this link to see it: learning_immunoassay

Different companies making different machines have their own patented differences in these tests so they are not all identical. However, practically speaking, these tests in themselves are exceedingly accurate. The big diagnostic companies that develop these tests have validated their accuracies very diligently.

You would have realised by now that these are all just different detection techniques. They are but one piece of the puzzle of HIV test accuracy.

These are basically tools at the doctor’s disposal. But if the tool is used wrongly, it is useless.

For the test to be accurate, we must do the right test at the right time. Doctors need to know at what point in time to use which tool to detect what.

So in summary, the HIV CMIA test is very accurate in detecting HIV antibodies and HIV antigens. There is no reason to doubt their accuracy.

However, to know if the patient is infected with HIV or not, the doctor has to know when to order the CMIA and decide if the CMIA will test for antibodies or antigens or both.

If you have any questions, visit our free online forum on sexual health, HIV and STDs.

If you had a high risk exposure to HIV within the past 72 hours, you can take medicines to reduce your risk of actually contracting HIV. Find out more on HIV PEP Treatment.

If not read more about HIV symptoms.

Can’t wait for 3 months to find out? Find out more about Anonymous Rapid HIV Combo test at our clinics.

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578 Comments

  1. Hi Doc, how long will it take for HIV ag/ab CMIA to detect HIV 2?

    Tested with HIV ag/ab CMIA at BPHealth:

    21 days: non reactive
    28 days: non reactive
    41 days: non reactive

    I just don’t feel right. 5 days after exposure, been having mild fever, sore throat. Then a week after cough that last for about a month. Recently, my left groin suddenly have lesion and near my anus I got boil (that’s wht the doc said but I think it’s swollen lymph node) And sometimes I feel some kinda pain at pelvic area.

    Exposure: massage parlor lady do handjob which I believe got vaginal fluid on her hand. What should I do?

  2. Hi doctor,

    I had exposure on June 30 and took cmia abbot method test on Aug 10 and negative,
    Do I have to take retest after 3 months or 12 weeks

    • If it was a 4th generation Ag and Ab test (most lab based tests are nowadays), then I would consider your testing conclusive. If it was an Ab-only test, then you may require another test at 3 months.

  3. Hello doctor.. i need your advice.

    I am male. I had protected vaginal sex with massage therapist about 9 weeks ago. I also had recieved unprotected oral sex from her, deep kissing, and did vaginal fingering.

    After that, i have done several HIV & STD testing after exposure :
    1) 2 weeks : 3rd HIV 1/2 rapid test, Non Reactive
    2) 3 weeks : 3rd HIV 1/2 rapid test, Non Reactive
    3) 4 weeks : SD Bioline HIV rapid test, Non Reactive
    4) 4 weeks : STD screening test (Hbsag, Anti HSV2-IgM, Anti Chlamydia Trachomatis IgM IgG, and Gonorhoe cek) all the result are Negative
    5) 5 weeks : CMIA Ag/Ab combo (the laboratory Analyst told me about this CMIA test can detecting reaction HIV antigen P24 and HIV 1/2 Antibody using a tool called abbott architect with sensitivity and spesifity 100 percent, they also called this test as a combo test) and the result also Non Reactive.
    6) 5 weeks : syphillis screening cek (vdrl/rpr and TPHA) also Non Reactive

    My concelor doctor told me that no need to re-test again. But i need second opinion from you.

    Doc.. i have several question for you :

    1) Are my all test result both HIV and STD screening are conclusive or should i re-test again? Fyi, my doctor told me to consume maxprinol as a preventive measure against transmission of herpes at week 3 till week 4. does this medication affect to my HIV test results?

    2) Does the CMIA test I did at 5 weeks after exposure is a 4th generation HIV test type?

    3) in my country indonesia use 12 weeks or 3 month window period. if i concern to re-test again using 3rd HIV rapid test, Are there differences in results between tests that conducted at 12 weeks (84 day) and 3 months (90 day) or negligible?

    Please doctor, i need your answer. Thank you.

  4. Hello doctor , tq for your time reading my question , i had exposure at 19:00 21 july 2018 then took CMIA ag/ab combo test at 10:00 18 august 2018 ( 28 days or 27 day 13h exposure ) with result 0.08 non reactive. My question is

    1. Is the test im taken is 4th generation duo/combo that look for p24 antigen

    2. Is it 27 day 13h is considered 28 day after exposure.

    3. Is my test considered conclusive and should i take another test at 3 month mark ?

    Thank you again doctor for your time.

    • I would consider your testing conclusive. However, you should discuss your testing and risk with your doctor if you are still concerned.

  5. Hi Doc,
    1)I read in some blogs mentioning that Hiv 1 and 2 wont show up till 10years,even being infected.Is it true?
    2)Few more blogs mention that it wont show up till 2 to 3 years.Curious to know the fact?
    3)what is Seronegative?

    Thanks in advance

  6. Hi dr… I have some question

    1. I have unprotected vagina sex.. After 95 day of exposure… I did a hiv screening cmia ab/ag and result come out non reactive. . Is it conclusive result? Do i need repeat at 6month post exposure?

    2. How to know 4th gen hiv test? Is it hiv screening cmia ab/ag test a 4th gen test?

  7. Hi,
    I’ve taken a 4th gen CMIA test and NAT at 28 after exposure and the results are negative. However, on the 6th week I have sore throat and runny nose. Are my results considered as conclusive?

  8. Hello after sexual exposure I started worrying about catching hiv so,I did pcr and combo test after 3 days then it came negative after that I search through the internetn, I found it is not the enough time to do the test,so the bad thoughts that I have hiv return back I start then searching about the tests window periods I found that it is quite enough to get tested at 4 weeks and it is conclusive I took the combo test and also came back negative but also I still worrying too much Is it enough

  9. Brick9799

    HIV Ab/Ag Screening (CMIA)test after 7 weeks of exposure.
    It is negative.
    Is it conclusive?
    I test at Malaysia BP Clinical Lab.

  10. airus

    hi doctor,

    I test lab,HIV1,2 Ag/Ab Screening 4 genaration n result Non-dedacted 55 day of exposure.
    my result conclusive or repet 3 mothn.

  11. hi doctor
    I test
    *HIV Ag/ Ab Screening (CMIA) 4 genaration n result Non-Reactive 49 day of exposure.
    my result conclusive or repet 3 mothn.

  12. hi doctor..
    I test hiv 37 day.4 genaration.hiv Ab/Ag (cmia) : non reactive. my hiv test conclusive or test next 90 day?.

  13. Crazy

    Hi Jonathan,

    1)Thanks for your prompt reply…
    2)I read in some blogs mentioning that Hiv 1 and 2 wont show up till 10years,even being infected.Is it true?
    3)Few more blogs mention that it wont show up till 2 to 3 years.Curious to know the fact?
    4)what is Seronegative?

    Thanks in advance

  14. Crazy

    1)Does Hiv 1 and 2 lay dormant? If so till how many years it will be dormant?
    2)Non-reactive test with 0.12 results are conculsive for the exposure which happened 2 years prior?

    • If by dormant, you mean undetectable, then no it does not. Yes, your results would be conclusive for that exposure.

      • Crazy

        Hi Jonathan,

        1)Thanks for your prompt reply…
        2)I read in some blogs mentioning that Hiv 1 and 2 wont show up till 10years,even being infected.Is it true?
        3)Few more blogs mention that it wont show up till 2 to 3 years.Curious to know the fact?
        4)what is Seronegative?

        Thanks in advance

  15. Hi,
    I am a male. I had received an unprotected blojobs from a girl. Have tested hiv and other std after 29 days and found negative. Method of hiv test is CMIA. I want to know whether it is 3rd generation of forth generation test?

    Thank you in advance for your support!

    • CMIA testing can be done both as 3rd gen (antibody-only) or 4th gen (antigen + antibody). You will have to speak to the people who did your test for confirmation.

  16. airus

    doctor, I test hiv cmia,28 day non reactive.is this correct ?

    • If it is a 4th generation test (checks for HIV antibody and antigen), then I would consider it conclusive. If it is a 3rd generation test (antibody-only), it is not conclusive until 3 months or more post-exposure.

      • airus

        yes..4th genaration. hiv ag/ab screening cmia: non rective result.

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