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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.

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  1. Harpreet Singh

    I have test hiv test at 11 weeks ?
    Is this correct ?

  2. Harpreet Singh

    Tri-dot hiv test are which genration ?

  3. Hello doctor.. I have done hiv cmia test on 23 daya after exposure.. Is the result conclusive?? Or should i re test again

    • The test is a good indication, but for conclusive results we would advise a repeat test (4th generation Ag/Ab combo) at 28 days or more post-exposure.

  4. Harpreet Singh

    Doctor i had unprotected sex on 26.01.2018.

    I had Hiv 1 & 2 Antibody screening test,serum @
    Hiv 1 & 2 & p24 combo test

    Result was:

    23.02.2018 (Day 28) : 0.38 (Non Reactive)

    is this correct ?

  5. Anxious

    Doctor, i have done multiple test. Last unprotected sex august 17.

    Test i have done =
    Early jan 18 :
    – vdrl (rpr) : non reactive
    – rapid anti hiv : non reactive

    Late feb 18 :
    – hbsag : non reactive
    – cmia anti ag/ab combo : 0.07 (<1 non reactive)

    Do you think i need re test despite having done post 3 month and post 6 month test?

    • Dr. Julian Ng


      I would consider your results as conclusive. There is no need for further testing for HIV.

      • Hi Doctor,

        My test are CMIA HIV 1/2 P24 and I had them at 30;65;82:140 days post exposure. A total of 4 tests with all non reactive results. Over and above these four tests I did a RNA PCR for HIV1 at 10 and 82 days which were not detected. Now given a total of these 6 tests, would you say conslusive irrespective of the symptoms I have. I have a fungal mouth infection which refuses to go and a swollen lymph node under my arms and a swollen gland behind my knee. What is your opinion doctor ?

        Thanks in advance for your help.

        • Dr. Julian Ng


          I would consider your results as conclusive and there is no need to go for further testing. However, you should visit a doctor for your symptoms as they could be due to other conditions and will need to be evaluated.

  6. Harpreet Singh

    Hello sir

    Hiv 1 & 2 antibody screening test,
    serum @ Hiv 1& 2 and p24 combo (CMIA) at 27 days non reactive ?? is this correct

    • Dr. Julian Ng


      The recommendation for 4th generation HIV test is to do it after 28 days post-exposure; My suggestion would be to repeat the test after 28 days.

  7. Nikhil


    I had unprotected oral sex with a prostitute 2.5 months back i was the reciever and i did cmia duo test for hiv 1/2 antibody and p24 antigens and the result was 0.14. Am i still at risk of getting hiv from that incident ? Do i need to get myself tested 3 months post exposure or my test results are conclusive? Should i still need to worry ? I have not been able to sleep since last 2 days.

    • Your test is conclusive. However, there is still risk of other STDs including chlamydia, gonorrhea, syphilis, and herpes. If you are concerned, please visit us for a proper consult and testing.

  8. Dr, may i knw the result of hiv rna pcr test conclusive if done at 10days? How different 9days 20hours or 10days? And tge day of expose is consider one day?

  9. Hello doctor, I am from Indonesian.
    On December 28, 2017 I action at risk of HIV-infected, on March 21 2018 (12 weeks/84 days) I test method 1 CMIA with the results of Non-Reactive.
    my question :
    1. Is such tests are the final result ?
    2. Do I have to do retest?


  10. After 108 days meia test is conclusive

    • Hello dear please help me .i have handjob with hiv positive person person without condom.i have done hiv combo test after 19 day 32 day 53 day 82 day and 130 day all came back negative .please tell me i nead more test .i have white tounge and bad taste my mouth please help me.

      • Dr. Julian Ng


        Your results are conclusive. However, if you are concern about your symptoms on your tongue please visit a doctor for further evaluation.

        • Dear Doctor,

          Please help and guide me. I had a 10 day PCR RNA not detected post exposure and three duo tests at 30,65 and 82 days non reactive. I also had one PCR RNA at 82 days not detected. Am I 100% clear or any further testing required for both HIV 1&2? Trust your advice. Thank you!!

          • Dr. Julian Ng


            Assuming that your duo tests refers to the 4th generation HIV Ag/ Ab tests, I would consider your results as conclusive.

          • What is the window period of a third generation test ?

          • Dr. Julian Ng


            The window period for 3rd Generation HIV test is 3 months.

  11. Nicholas

    Hi, doctor taking prednisolone will affect the test? (Hiv ag/ab cmia) test was done in 41 day after expose, will it be conclusive?

    • Dr. Julian Ng


      At this point in time, there is no indication that prednisolone could interfere with the results of HIV CMIA test.

  12. Hi, doctor I done my ag/ab
    cmia test on 40days after expose it shows non reactive, is it conclusive?

    • Dr. Julian Ng


      Generally, 4th Generation HIV testing if done after 28 days after exposure is conclusive.

  13. Doctor i had unprotected sex on 02.01.2018.

    I had Hiv 1 & 2 Antibody screening test serum @
    Hiv 1 & 2 & p24 combo test

    Results were:

    19.01.2018 (Day 17) : 0.29 (negative)
    16.02.2018 (Day 45) : 0.10 (negative)

    Does these test are conclusive orr do i need to test again?

  14. Hi doc, i did cmia 4th generation ag/ab on my 25th and 5weeks after my protected exposure. both nonreactive first was .18 last was .13 Is this conclusive and am i 100% safe? and based on your exp. what was the earliest youve detected a positive person using 4th gen? thank you

    • I would consider your tests conclusive. I have tested patients positive on Day 16 of exposure with a 4th gen test.

  15. Doc. What does it means if CMIA test is reactive, but ELISA method is non reactive. Which one is accurate and the possibilities to get positive or negative HIV?

    • You would be advised to repeat testing or go on for a confirmatory Western blot test. Diagnosis of HIV requires 2 tests to be positive.

  16. Dear doctor, dokter, I did CMIA test at 30 days after potential exposure,
    , is my result conclusive enough with this method at 30 days ?

  17. hi doc, tested on 25th after exposure(protected sex)with 4th gen cmia result is 0.18 negative. what is the chance to change the result after 3day(28thday)? would you consider test on 25thday also conclusive? or do i need to test again? may i ask about p24. according to your chart p24 antigen is detecteble with 14 we can say that if we dont have antigen in our body theres no chance to have antibody? im i right? please enlighten me. thank you.

    • Your tests are a very good indication already, and I would not be worried at all. However, for conclusive results, it is advisable to repeat testing after 28 days.

  18. hi doc,tested 14days and 25days after exposure(protected) with 4th generation cmia.the result are both nonreactive. do i need to retest? thank

    • I would consider your tests very indicative, but for conclusive results please repeat one at 28 days.

      • Harpreet Singh

        Hiv 1 and 2 antibody screening test
        serum @ Hiv 1 and 2 & p24 combo (CMIA)

        Non reactive at 28 days…is this correct ?

  19. hlo sir I did hiv 1 2 antibodies and p24 antigen test in 32 days by CMIA method.and resupt came afte 1 week with non reactive .is it conclusive sir or shpuld I need to retest in 3 months. I am too anxious about hiv in my body .

  20. Hello sir, I had unprotected sex with women on 28th Oct 2017…after this exposure I tested for HIV using 4th generation test (CMIA) 6th day, 73th, 86th day and HIV rna pcr test on 48th day all were negative…..but in this period I have symptoms like cold sore throat and abscess…is abscess is related to it????
    The lady with whom I had sex also tested for HIV on7th, 14th and 25th day results were negative… But on 25th day she was admitted to hospital and and Dr. Confirmed she has blood cancer…. I just wanted to know is blood cancer had any effect on her HIV test???Thank you

  21. sir already test CMIA for about 3months it is conclusive.. the test is.. 0.57..

  22. Dr tan,

    I tested hiv combo p24 ab/ag CMIA after 7 months and after 2 years and after 3 years, it was abbot architect hiv combo p24 ab/ag test.
    Shall i trust this testing method and move on?

  23. I have done cmia test at 21 days and the result is negative ..
    Is the result conclusive ?

  24. I am a gay man and had an encounter and it was about oral sex (the other man gave me a blowjob) and I fingered him (my finger into his anus).
    He tested negative (I asked him to be tested) two days after we had sex and it was negative (combo ab/ag 4th generation lab test). I got tested 43 days with the same combo ag/ab 4th generation lab test and it was negative.
    Do I need any further testing?
    Thank you in advance!

  25. Hi Doctor,
    I exposed protected sex 60days back, from that day onwards I feel flu symptoms. but I can manage the things daily.
    1 week back I had some tests like HIV ! & 2 (AG & AB) method (ECLIA), VDRL, HSV1 ,HSV2 $ Chlamydia . every thing is fine, except HSV1 , I got result as 2.heard that usual range should be less than .56 ?
    but I have mouth ulcer issue from childhood onwards.
    HSV1 is dangerous ? it will leads any big issue ? is there any treatment for this ?
    Please clarify on this thanks

    • I cannot interpret your results for you, suffice to say HSV-1 is a common virus that about 60% of adults already have. Most transmission is during childhood. They may or may not cause symptoms such as cold sores. It does not usually lead to longterm health problems but in rare cases can cause serious complications. There is treatment to suppress the virus but no cure.

      • Hi Doctor,
        thanks for the clarification.
        regarding HIV can I confirm my test is conclusive ?

  26. Hello doctor
    I had exposure 4 month ago I tested from elisa hiv 12 test kit looks sacond generation and pcr rna qualitative not detected and Elisa also not reactive can I say it am 100 per free from hiv

  27. Hi doctor,

    Hope you’re doing well.
    I had my blood at 36day after exposure and it came back with non-reactive.
    But I’m still having diarrhea for a few days and i had a red bump on my back but healed and now it’s at back of my neck in a small.

    Should I go for a retest ?

    • If it was a combo p24 antigen and antibody test then it is conclusive. If it was just HIV antibody then the results are only considered conclusive after 3 months.

      • Yes,it was ag and ab combo cmia test.
        The test was for herpes,std and few more.

  28. Sir,
    I did oral sex with a girl on September’16 …i was receiving… No cum occured..
    I was tested for hiv during a SDP donation after 2 months of the incident.. result was negative..(dont know the process of test) … Then due to intense fear of getting hiv from that exposure I again did a CMIA test this year on 1st july (2017) .. this was also negative… No further exposure happens during this time… So is it conclusive that I am hiv negative??

  29. had my cmia hiv1/2 and p24 after 43 days of exposure. index value 0.09. how good indicator is it?

  30. Ricky234

    Help needed!!!!!, I feel I am sero converting at day 45.swollen lypmh nodes under neck and high fever.I have tested hiv combo with p24 on day 28 and 40 after exposure both tested non- reactive. Can the 4th generation test detect hiv virus if I haven’t sero converted??
    Looking for a reply please doctor?

    • Yes, your tests are conclusive and therefore there is no reason for your symptoms to be due to HIV. Please see a doctor for a proper assessment. Many other conditions cause fever and swollen lymph nodes.

  31. Had unprotected vaginal sex, high risk exposure.. I did cmia combo test on day 50, 7 weeks after exposure.. results non reactive.0.16!!
    Sir are these test conclusive do I need more test?

  32. Had a high risk exposure, unprotected vaginal sex..tested for cmia combo test after 50 approx 7 weeks, is this test conclusive?

  33. Sir, I have done four tests CMIA method, index value .16,.09,.09 & .05, what does this index value say?

    Is it okay (the last test was done after a year ) ?

  34. CMIA result

    Hello Doctor,

    I received the 3rd month post exposure result of my hiv test using CMIA fourth gen. It turned out non reactive.

    My question is, I was handed two papers that both indicate 0.14 for the result and 1 for the cut-off value, is it normal to have the same result value for both ag and ab? There were no indications which pertains to ag and which to ab on the two papers and both papers are exactly the same.


  35. Hi doctor,
    I have a few queries regarding the HIV CMIA test. I have taken 3 tests till now, the last one 4 months after exposure. The result was non reactive with an index of 0.24 . However I did read at a few places that the test is unable to detect the rare strains of Hiv like N, P, and CRFs as well. I’m wondering whether it’s a correct result as it is possible to get infected by a rare strain too. Should more specific tests be needed for detecting these ? I constantly feel like I’m dizzy and in a drugged state and my symptoms have now persisted since more than 3 months now and I don’t feel like they are going to go away. I was also diagnosed with vitamin b12 deficiency and after subsequent medication my b12 levels have gone beyond 2000 but I don’t see the residual symptoms go away. Need your help.

  36. Dear sir,
    Before 1 year i have a sex with a girl and condom was stucked inside her vagina after 6 month i was doing a hiv 1 and 2 cmia test the result was non reactive with score of 0.15. Before two days i am doing the same test in Metropolis lab the result is non reactive with the score of 0.14

    Please help me this test is enough i am not infected with hiv i am so scared pls help me sir….

  37. Dear doc,

    I took a combo test(CMIA) at Dr. Lal path labs in delhi. It’s a highly reputed lab. The test was taken at 21, 26 and 37 days after possible exposure, with non reactive each time at 0.11, 0.12 and 0.1 respectively (MSM, condom broke, receptive partner).
    You think the results are conclusive?

  38. I bought a beer from beer shop.i had opened it myself.beer was tastless.my query is ,is it possible that shopkeeper opened it before and if he did this,and dranked it,can I will be infected with HIV?

  39. Doctor i test after 22 Days and 38 days after exposure with non reactive result. My question Conclusive or not? Or i need test after 3 month? Thx doctor

  40. gedhang

    Ok dr. If i repeat at 2 month with cmia method is the result can conclusive?

  41. gedhang

    Hello dr. I have done hiv test method cmia hiv at 1 week and 3 weeks after expose. All test negative.
    My question:
    1. Is conclusive 100%?
    2. Should i retest back?

  42. Sir …. i did CMIA test at Lala path lab at 47 ,100 ,120 days post my exposure…. Result is Non Reactive….

    I also make RT- RNA PCR Quantitative at Lal Path Lab result is Target not detected.

    Further tests are required or not….. if required then which test and when…??

  43. Hello doctor i did hiv 1/2 p24 antigen combo cmia 4th generation test at 40 days and 78 days all were non reactive is it conclusive or i need to retest at three months????

  44. Hello doctor i had a 4th generation test at 40 days and 78 this test is 4th generation combo cmia .is it accurate or i need to test at 90 days again

  45. Hai Doctor,
    I had sex with unknown girl on 24th June 2017. I did HIV Ag/Ab screening CMIA test on 12 July 2017 (on 17-18 day after exposure) and result is non-reactive. My question is:

    1. Is the test I did is called combo test?

    2.i want to know what is the accuracy ( maybe in percentage %) of negative results after 17-18 after I did sex with unknown girl?

    3.Based on your experience doctor what is the chances in % to remain negative in future?

    Please reply Doctor. I can’t concentrate on my studies due to stress I did big stupid mistake.. Thank you

    • Yes, this is a combo test. Your test is a good indication, but we cannot give a specific percentage of accuracy after 17-18 days. Different test manufacturers will provide different sensitivity numbers. If you are concerned, just repeat your test at 28 days or more.

      • Thank you for your reply Doctor.. really appreciated.

  46. Hello dr. I have don hiv test from dr.lalpathlab method cmia hiv 1/2 & p24 at 1,3,6 and 8 months after expose. All test negative.
    My question:
    1. Is conclusive 100%?
    2. Should i retest back?
    I am still worry about my hiv status should i go for another test pls . Help me

  47. Hi from the diagram u provided if the testing occur after 48 days is it not accurate? Or if the test were done after 48 days basically all generation test will pickup the reaction? Is that what it means?

  48. Hello dr. I have don hiv test method cmia at 1,3,6 and 7 months after expose. All test negative.
    My question:
    1. Is conclusive 100%?
    2. Should i retest back?
    Sory my english not good, hope you understand.

    • You do not have HIV and do not require further testing unless you have had any additional exposure.

  49. sir Plz help me I beg u…. I had protected sex with a girl whome HIV status I m not awear……I m not sUre whether condom got broked or not…. I have done cmia 4th gen test which can negative….do I go for futher test coz I feel all time my stmoch is full….no mood to eat each time

    • I cannot verify the accuracy of your HIV test. Please see the doctor who did the test for you.


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