Could I Take HIV RNA Test After Ten Days Of Exposure?

Posted on Mon, 11 Nov 2013

Question: Hi
I would like to know if 7-10 days after exposure is a good timing to perform an HIV RNA test?
Also, is there any specific question I should ask the dr about the test: Brand, method, etc....

Thanks

Answered by Dr. Roopa Hiremath (1 hour later)

Brief Answer:
HIV RNA test can be done

Detailed Answer:
Hi,

HIV RNA test is based on the principle of PCR (Polymerase Chain Reaction).

HIV after entry into the body multiplies in the lymph nodes and then spills back into the blood 4-11 days after exposure.

So there is no test which can detect HIV within 4 days of exposure.

After 11 days of exposure, the only tests which can be used for HIV detection are HIV RNA test and P24 antigen test.

I would suggest you explain details regarding the HIV exposure to your doctor so that he can decide whether you require the test or not.

Many HIV RNA tests are available commercially but better to use FDA approved ones. (for reliability)

I have mentioned a few below but you can confirm this from your treating doctor depending on the brand available in the testing lab.

FDA approved HIV RNA tests:
1. Biolife Plasma Services
2. Roche Molecular Systems
3. Abbot Molecular Inc.
4. Siemens Healthcare Diagnostics

After this test, please ask your doctor if you require any further testing and if yes, when to return for the next test.

I hope I have answered your query satisfactorily.

Thanks.

Above answer was peer-reviewed by : Dr. Shanthi.E

Follow up: Dr. Roopa Hiremath (4 hours later)

Many thanks Dr

If the PCR RNA results, is the

Answered by Dr. Roopa Hiremath (1 hour later)

Brief Answer:
Question not clear.

Detailed Answer:
Hi,
Please complete the question.
Thanks.

Above answer was peer-reviewed by : Dr. Raju A.T

Follow up: Dr. Roopa Hiremath (5 hours later)

If the PCR RNA results are negative 11 after the exposure, is there a lot of chance that an a duo test 28 after exposure or a standard antibody 3 months after exposure to be poitive?

Have you ever seen, heard or read about someone testing negative with a PCR RNA 7-10 after exposure who end up being actually HIV+ after?

What is the sensitivity of the PCR RNA 7-10 days after exposure?

Why there's some much difference about the window period of PCR RNA in the litterature?

Many thanks

Answered by Dr. Roopa Hiremath (6 hours later)

Brief Answer:
HIV testing details

Detailed Answer:
Hi,
Welcome back.

This is a very good question. I want to explain few points about sensitivity of PCR test and follow ups for HIV testing.

PCR for HIV RNA is one of the sensitive tests done during early exposure. There is less likely chance of PCR missing HIV.

This is one of the tests of choice in window period.

Window period - The period following the entry of HIV into the body and the appearance of detectable levels of antibodies is called “window period”.

This varies from 3 weeks to 12 weeks depending on the viral load and immunity of the patient.

HIV status confirmation - A person is announced as HIV positive or HIV negative based on test results of at least two different tests.

Meaning two consecutive tests should give positive results for giving the report as positive.

Similarly two consecutive tests should give negative results for giving HIV negative status.

I have not heard or seen PCR RNA being negative and then patient turning positive later. But there is a possibility of this occurring in babies born to HIV positive mother where HIV detection is controversial.

I hope I have answered your query satisfactorily.

Thanks

Above answer was peer-reviewed by : Dr. Shanthi.E

Follow up: Dr. Roopa Hiremath (1 hour later)

Many thanks for your comprehensive answer

I've a few last ones:

1) you're mentionning that the window period varies from 3 to 12 weeks. Isin't shorter for pcr rna? I tought it was more like 4-11 days?

2) when you say you haven't heard or seen PCR RNA being negative then positive later, you mean later than 11 days?

3) I called the hospital and they do provide a qualitative PCR RNA Nested. Is it a good one?

4) do you recommend to wait 14 days to do the PCR or 11 days is enough

Many thanks agai

- You mention that the wun

Answered by Dr. Roopa Hiremath (43 minutes later)

Brief Answer:
Window period is not applicable for PCR tests.

Detailed Answer:
Hi,
Welcome back.

Window period is always taken into consideration for detectable levels of antibodies against HIV as these tests are the most routinely done tests. During this window period, the person might be negative for HIV antibodies but still be infected by HIV.

Since PCR does not work on basis of detecting antibodies, it is one of the choice during this interval. It's sensitivity is proved after 4 days of exposure; so the test after 11 days of exposure is good enough to confirm / exclude HIV.

RNA Nested PCR is a reliable test. This test can detect RNA as little as 10 nanograms. So if HIV infection has occurred then PCR will definitely detect the HIV particles in the blood.

I would suggest to go ahead and get the test done to relieve your anxiety regarding HIV exposure.

Thanks

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Above answer was peer-reviewed by : Dr. Prasad