Dr. Tan and Partners is one of the few approved Anonymous HIV Testing Centres in Singapore. A detailed write up on our service is available here.

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HIV 4th Generation Test Singapore

The HIV 4th Generation Test is one of the most accurate and fastest way to determine is a person has been infected with HIV or not.

The HIV 4th Generation Test is also called the Combo test or the Duo test.

It tests for both the HIV antibodies as well as the antigens in the blood. It can be done as a rapid test i.e. you can get the results in 20 minutes.

Antibodies are produced by the body when it is infected with the HIV virus. There are many different types of antibodies. The one that is produced the earliest is called the IgM antibody. This can be produced as early as 20 days post exposure. 3rd and 4th Generation HIV tests can detect the IgM antibody.

Antigens are bits of the HIV virus shell that can be found in the blood as early as 14 days post exposure. The 4th Generation test can detect the presence of this antigen.

If the test detects either the presence of HIV antibodies or antigens, it means the patient is most likely infected with HIV. This has to be confirmed with another ELISA test. We always do at least 2 tests before diagnosing a person as HIV +ve.

Officially it is conclusive at 28 days post exposure. However, from current scientific data, we know that when the test is done at 20 days post exposure, it is already as good as 100% accurate. 

That said, guidelines still require patients to be tested at 28 days post exposure so that is still the recommendation by Doctors. Personally, I have tested patients +ve for HIV at only 14 days post exposure with this test.  

The US CDC recommends the HIV 4th Generation test for all HIV screening. This is because it is more accurate, has a shorter window period and can pick up rare cases of sero-negative infections (see below).

The HIV 4th Generation test can detect HIV infections in very rare cases of people who are infected with HIV but never produce any anti-bodies. These are called sero-negative infections and happen in about 1 in 1 million people.

At our clinics the 4th Generation HIV test costs $162.00.

You can walk in to any of our clinics in singapore and malaysia during our opening hours for this test. It only requires a finger-prick of blood and 20 minutes to get results.

Also See: Rapid STD Screening (Next Day Result)


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If you need an HIV test visit Our Clinics anytime during our opening hours. You do not need an appointment.

Find out more about Anonymous HIV testing at our clinics.

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

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.

Related Topics:

Anonymous HIV testing at our Clinics

HIV – Understanding the Window Period

Cost of HIV/STD tests at our Clinics

Condom Broke

Getting HIV from Oral Sex

More on HIV symptoms

How long can HIV live outside the body?


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All Our Doctors are Fully Certified and Trained to conduct specialised STD Screening,  STD Testing & STD Treatment and HIV Testing.

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About Dr. Tan
Dr. Tan graduated from the National University of Singapore in 2001. His residency was in the two largest public hospitals in Singapore; Tan Tock Seng Hospital and Singapore General Hospital.

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  1. Kyle L Denman


    I had receptive anal intercourse with the same person 11/24/2018 and 12/1/2018. Both times the condom broke and the intercourse was not complete between myself and the other person, meaning there was only pre-cum as a risk factor. I was tested on 12/8/2018 14 days from the initial contact and again due to nerves on 12/11/2018. This was 17 and then 10 days from potential exposures. When will my test be valid? The clinic that tested me stated that the initial exposure window period has already lapsed as I was tested with the 4th generation test, and it would have shown a positive result. Can you please provide a recommended suggestion? Are these results accurate? I have been worried that every ache and cough has been related.

    • Your test results so far are a good indication, but for conclusive results with 4th generation testing we would recommend testing 28 days or more post exposure.

  2. 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: Me and massage lady naked. No intercourse. I suck and lick her nipple. Massage parlor lady do handjob which I believe got vaginal fluid on her hand.

    Should I get tested for HCV in case of coinfection and delayed detection?

    • You cannot get HIV or HCV from this type of exposure. If you have a skin lesion that you are concerned about, please visit us for a proper consult and evaluation.

      • I read somewhere that says someone with herpes virus increases the probability of the hiv transmission. More than 2x easily.

  3. doctor
    I had unprotected anal sex with someone I dont know hiv status status
    I visted a doctor who put me on pep after 17 hours of exposure
    I got 4th generation Ab/ag at 40 day -10 days after finishing pep- Negative
    I am so scared
    Is my result conclusive – if no conclusive, what is the percentage test will be positive later?
    I cant function in my life and I am so scared
    Please help me doctor please

    • I would consider your tests essentially conclusive. However, just as a precaution it is still recommended post-PEP to complete one last test at 3 months.

  4. Hi Doctor,I have visit an sex worker for vaginal sex with condom.But after few minutes ,I found out the condom is slipped half way while she is on the top.After I pull out my penis,the condom is still covered my forehead.In your opinion do u think I need to take pep.

    • There is a low risk of HIV transmission from this exposure, but PEP can still be considered. It would be best if you come down to our clinics for a proper consultation and risk assessment, from which you and your doctor can make a decision as to whether PEP is suitable for you.

  5. Hello doctor and thanks ahead for your help.

    I had unprotected incertive anal sex for 15 seconds.
    I panicked
    Started PEP Truvada and Tivicay 14 hours after exposure and completed my 28 days with the highest adherence. No symptoms during the 4 weeks post exposure.
    – RNA PCR at 11 das post exposure negative.
    – 4th generation at 23 days post exposure negative
    – 4th generation at 31 days post exposure 3 days post PEP completion negative.
    Is my result conclusive?
    If not when should I test again for conclusive result?

    Thank you very much

    • I would consider your test at 31 days fairly conclusive. However, as a precaution, guidelines will still recommend one last test at 3 months, of which I am sure will turn out fine still.

  6. My last exposure is on 23/10/2018. Went to a massage parlor for happy ending. Went through the normal massage and when it comes to happy ending we both naked. I masturbate on my own while licking and sucking her boobs. Suddenly she handjob me which I believe contains vaginal fluid. 5 days after exposure, started experiencing sore throat. Went to the clinic and was given cough syrup, lozenges & Panadol. 5 days after, sore throat is getting better but still having mild fever and bodyheadache. Went to the second clinic and was given Panadol, lozenges and antibiotics. After sore throat becomes better, started experiencing cough. Went for testing on 20th day after exposure (HIV ag/ab non reactive). Then went again for testing on 28th day after exposure with HIV ag/ab, also non reactive. But I’m still having mild fever on and off up till now, cough started back on and off.

    • As I have mentioned, your HIV tests are conclusive. If you are still concerned about symptoms, we would need to do a proper assessment. Please visit us for a consultation.

      • Went for testing again at 41 days (non-reactive). But by baby has had his 3rd fever this month alone!and this time with vomiting. And my wife keep having back pain and headache. What test should I take? Or should I test at other centre in case the lab that I went now does not know what they are doing?

  7. My last exposure is on 23/10/2018. 5 days after expose, started experiencing sore throat. Then mild fever for about 3 weeks, on and off. Went for testing on 20th day after exposure (HIV ag/ab non reactive). Then went again for testing on 28th day after exposure with HIV ag/ab, also non reactive. But I’m still having mild fever on and off up till now. What other test should I take?

    • It would depend on your symptoms, exposure type and risk, and examination findings. I would advise you to visit a doctor for a proper consultation and evaluation if you are keen to discuss STD testing. I can say that your HIV test results would be considered conclusive.

      • Exposure:
        Went to the massage parlor for happy ending. I don’t do intercourse with her. Masturbate on my own at first but then she suddenly do handjob to my didi. I think her hand got vaginal fluid by pleasuring herself.

        • Went to massage parlor for happy ending. Did the normal massage and when it comes to happy ending we both naked, didn’t do intercourse with her. I masturbate on my own while licking and sucking her boobs. Suddenly she do handjob to me which I believe there is vaginal fluid on her hand when she mastubated me because she pleasured herself before.

      • Should I get tested again at 8th and 12th week?

      • And I frequently feeling hungry now. Does it mean the virus has absorb the good nutrients that body needs? And I have been having this cough and runny nose lately.

        • And today, I have swollen lymph node at groin area. Like a real lymph node. Not a made up. And it’s painful when touched.

  8. Hi Doctor. I had protected vaginal sex with a girl but my worry is that after that, as i couldn’t complete, she removed the condom and gave me a handjob with the same hand.

    I have done the 4th gen Alere combo test 25 and 33 days post exposure, both negative.

    What do you make of my results based on my exposure risk?

    • Your HIV tests are conclusive. If you are still concerned or are keen to check for any other STDs, please feel free to contact us for a consult and evaluation.

  9. Jose Villalpando

    Hello, does a 4th generation test done one day after finishing PEP reliable? From your experience does a negative test right after finishin PEP turned positve later on ?thank you

  10. Hello i did hiv- ag- ab test 42 days aftter expuree and result ots negativ do i need to repeat test latter or not

    • I would consider this testing conclusive already.

    • Jose Villalpando

      Hello, a 4th generation test donde one day after finishing PEP reliable? From your experience does a negative test right after finishin PEP turned positve later on ?thank you

  11. Allan Anonymous

    Hi Dr,

    I (Male) had protected oral and protected vaginal sex with a female commercial-sex-worker in Vietnam.
    I had the following test done at respective days after the exposure:

    (1) HIV 1 Viral Load (PCR) Test (Cobas Taqman HIV 1) Version 2.0 at 3 days after exposure – Result: HIV1 RNA not detected

    (2) Immuno Assay RNA Viral Load RT – PCR (Taqman Real Time PCR) at 6 days after exposure – Results: HIV1-RNA not detected

    (3) HIV-RNA Viral Load (Taqman Real Time – PCR) at 6 days after exposure – Results: Target not detected

    (4) Immuno Assay RNA Viral Load RT – PCR (Taqman Real Time PCR) at 13 days after exposure – Results: HIV1-RNA not detected

    (5) HIV Ag/Ab (Screening) (CMIA) at 27 days after exposure – Results: Non-reactive (not detected)

    (1) ALL 5 tests resulted NEGATIVE, can I now consider this as a conclusive result that I am indeed HIV Negative without having to do any further tests (considering the above 5 tests with 4 of them being PCR tests, supposedly very accurate)?
    (2) Does it matter that I took the last (5th) test on day 27 and not on 28th as recommended for Ag/Ab test?

  12. Justine

    Hello Dr is the 4th generation rapid test conclusive any time after 28 days? lets say at 35 45 or more or it has to be taken exactly at day 28 after exposure to be accurate. Thanks in advance for your reply.