Is Negative PCR RNA HIV Test After 17 Days Of Possible Exposure Conclusive?

Posted on Sat, 10 Oct 2015

Medically reviewed by Ask A Doctor - 24x7 Medical Review Team

Sat, 10 Oct 2015 Answered on

Tue, 27 Oct 2015 Last reviewed on

Question : Hello there,

I had unprotected receptive vaginal sex 4 weeks ago with somebody of unknown status. I became anxious so i took a PCR RNA test 17 days after the episode and my results were negative (flags were normal) Ive seen conflicting info online that you should wait until 21-28 days for something definitive. Do I have a reason to worry?

Answered by Dr. Nishad BN (1 hour later)

Brief Answer:
It is almost 99 percent accurate.

Detailed Answer:
Hi

Thank you for asking HCM.

I have gone through your query. PCR RNA test is almost 99 percent accurate. It works from 1 weeks post exposure. As you done it after 17 days it is more sensitive also. So you dont need to be worried.

You can do a HIV Duo test on 28 th day of exposure for assurance again.

Hope this may help you. Let me know if anything not clear.
Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar

Follow up: Dr. Nishad BN (6 hours later)

Great! So at 17 days something would have shown up for sure, regardless of lack of ARS symptoms? From my understanding, the RNA can catch HIV after only 72 hours, is that right?

Answered by Dr. Nishad BN (7 hours later)

Brief Answer:
Actual window period for this test is from 7 to 12 days.

Detailed Answer:
Welcome again.

Thank you for your follow up.

The actual window period for this test is 7 to 12 days. But it can be detected after 72 hour but not in all cases. HIV has a long range of incubation period also. Most get symptoms early like sore throat, rashes etc. As your RNA test is negative which is a highly sensitive test nothing to worry.

Hope this may help you. Let me know if anything not clear.
Thanks.

Above answer was peer-reviewed by : Dr. Chakravarthy Mazumdar