Why does my COVID-19 RT-PCR test results come positive on the first day, and negative after 24 hours?

Hello,

Welcome to icliniq.com.

I understand your query.

While comparing the rapid antigen detection kit, the sensitivity of the RT-PCR (reverse transcriptase-polymerase chain reaction) test is very high. It can detect even very few viral particles which can be otherwise missed with rapid antigen detection kits. Though it is highly sensitive and highly specific, still RT-PCR test cannot differentiate between live and dead virus particles. There could also be false positive RT-PCR test results due to issues like low-level reactions and sample contamination at the time of sample collection. Another reason for such occurrence could be attributed to persistent intermittent viral RNA (ribonucleic acid) shedding after symptomatic or asymptomatic COVID-19 infection for many months.

The next time, when you are getting tested for COVID-19, you can ask for the genes which are detected and CT (cycle threshold) value if the positive result comes. CT value of more than 35 indicates a low positive. This kind of issue is seen widely with the COVID-19 virus, but the exact cause and its significance are poorly understood.

Since you do not have any symptoms and no one around you has ever been tested positive or infected still date so there is no need to worry.

I hope I am able to clarify your doubt.

Take care and have a great day.

Hello,

Welcome back to icliniq.com.

I understand your query and I have gone through the attached documents (attachments removed to protect the patient's identity).

The first RT-PCR (reverse transcriptase-polymerase chain reaction) test result is positive and the N-gene is negative and, the second test result is negative.

In the test report with the positive test results, the 2019-nCOV RNA is positive, but CoV N-gene is negative. In cases of repeated positive test results after an episode of COVID-19 infection, which may be symptomatic or asymptomatic infection, the N-gene is considered as the main component in correlation with COVID-19 IgM testing for determining the re-positiveness of the result. The detected 2019nCOVRNA particles could be present due to an old infection further leading to the presence of fragmented viral particles which may be found intermittently in the nasopharynx. These could be detected in the RT-PCR test. One of the drawbacks of the RT-PCR test is that it cannot differentiate between live and dead virus particles.

In the absence of any symptoms or any illness, do avoid the COVID-19 RT-PCR test.

Take care and have a great day.