IC Test and NAT Test

Hello MedHelp Community,

A short while ago I posted a question about risks, and I am very anxious and I want to get tested now. I know that there is the ImmunoChromatography (IC) test and there is the NAT test, what are their window period,and which one has a shorter window period? I want to get tested soon and I think I am too paranoid to pass the 3 month mark.

Please help.
TX2000

[mechfab]

Im sorry to say it still 3 months to be sure. The early testing is not accurate. You will some people test at 6 weeks then at 12 weeks. Even if you did test now they would tell the same thing 3 months to be sure. I can not answer about those test that you are asking about, other may be able to. Good luck.

[mike_no]

Hi TX200,

Welcome to the forum, It would not be advisable to test on either of the testing technology, you have mentioned.

RIC test can't be helpful in early diagonisis of HIV because the window period for RIC is equivalent to a regular ELISA/ CMIA/ ICMA test.

NAT would certainly be a great indicator, and a method for early diagonosis. However, they are not a stand alone test, they have to be backed up by an antibody test at the 12th week.

I must say, an undectable NAT is a great indicator if you are ready to bear the cost, it's an expensive test.

Nucleic Acid Test (Polymerase Chain Reaction) :

1. PCR (NAT) tests directly look for the virus in the body unlike the Antibody test which looks for the body's response to the infection

2. PCRs are lately approved for diagnostic purpose however doctors may order for NATs if they feel that one is going through ARS since it enables appropriate treatment by early detection of the virus

3. Theoretically PCR can detect the virus as early as 72 hrs after the infection and the detection just keeps getting better along with the time since the HIV virus replicates itself in huge numbers every day, which means viral load keeps increasing every single day after the infection.

5. Comparison RNA PCR / DNA PCR:

RNA test detects the HIV virus directly in the body. The time between HIV infection and RNA detection is 9-11 days. These tests, which are more costly and used less often than antibody tests

But RNA (viral loads) can become not detectable in some (meaning not many) cases when the body finally fights back. But on the other hand PCR DNA tests are best used from 28 days on, but as early as 2 weeks, because these levels will not become undetectable over time.

So in short less then a month or during ARS, PCR RNA tests is best (9 -11 days after the exposure) but after a month a PCR DNA test would be best, but at this point an Elisa test would work just as good and without the risk of false positive which would make most people here go crazy.

6. RNA PCR is for early detection, test at the 14 th day after the exposure backed up by an antibody test at the 12th week is good enough to rule out HIV.

DNA PCR at the 28th day after the exposure backed up by an antibody test at the 12th week is good enough to rule out HIV

Both are NAT tests and are highly sensitive.

7.Drawback(very very unlikely though)
In some HIV positive individuals there are cases of undetectable viral load however a hypersensitive viral load test ( sensitivity -  50 copies / ml, 10 copies / ml) are good enough to detect the presence of the virus in the body.

8.Misconception about the PCR test (False Positives)
False positive rates have drastically dropped and every positive PCR is confirmed with another PCR for confirmatory reason, this eliminates the possibility of false positives, they are very reliable after 28 days, your result would be conclusive, however just for your own peace if mind back it up with a confirmatory test at the 12th week and move on.

In a nutshell, if you have the money to spend RNA PCR is a great test but one has to back it up with an antibody yest for confirmatory reasons only.

As per my research, most experts haven't seen a negative PCR result changing ahead

[alienshadow]

no matter what test you take before 3 months its not conclusive until then although on average its 22 to 34 days to show a positive result

[mechfab]

Thanks mike I learned a few things from that.

[tx2000]

Thank you everyone for the quick reply. I guess I should just wait a bit.

[alienshadow]

yes and quit reading on it all symptoms will start the moment the fear sets in ignore them trust me man

[mike_no]

Yes, correct you should wait, I can suggest you this, if you are anxious, get a IV gen - AB test at the 28th day from the date of your exposure. A 4th gen ELISA test is a reliable test and a good indicator due to the simultaneous p24 ag & ab detection ability, if you fare negative on it you should be rest assured that your 12 week result is highly unlikely to change.

The best part is, a IV gen ELISA would cost a few bucks more than a regular ELISA.

Hope this helps

[tx2000]

Does anyone know where I can get a 4th gen ELISA test in Tokyo then?

[tx2000]

Does anyone know where I can get a 4th gen ELISA test in Tokyo then?

[mechfab]

Sorry no I can not. I am in the states. Well e-mail the company who makes its and see if and where it is in Japan.

[mike_no]

Call up your local AIDS/HIV helpline and locate it.