RT-PCR negative, but you may still be infected by coronavirus

You may have tested negative in the rapid antigen testing (RAT) and then RT-PCR, which is considered gold standard for testing, too. Still, chances are high that you could be Covid-19 positive.

Doctors across the state are coming across an increasing number of cases where patients test negative in RT-PCR but their high-resolution CT (HRCT) reveals significant infection in the lungs.

The problem has become so acute that the Vadodara Municipal Corporation (VMC) has issued a notification stating that the current strain of Covid-19 does not necessarily show a positive test on RT-PCR but the insurance companies and third-party administrators (TPAs) should treat them as Covid. “In cases where RT-PCR is negative but findings in HRCT and lab investigations are suggestive of viral etiology, the claim should be treated as that of Covid unless proved otherwise,” states VMC’s order issued under the Epidemic Diseases Act


“I have come across patients who have tested negative in RT-PCR but their radiological tests revealed they require hospitalization. One patient’s score is 10 out of 25 in CT scan. This means that his lungs have already got affected,” said Dr Krutesh Shah, president of SETU, an Association of Private Hospitals of Vadodara.

Infectious disease specialist Dr Hiten Kareliya says he has started asking Covid-19 suspects to undergo RT-PCR tests and HRCT chest early instead of earlier practice where a patient would be asked to undergo CT scan only a couple of days after the test.

“We are seeing many cases where the patient has no symptoms or just mild fever and weakness but the infection spread to lungs rapidly,” said Kareliya

“RT-PCR’s sensitivity is 70% which means there are 30 % chances of false negativity. But if there is evidence in CT scan, it is Covid-19. In such cases, we go for repeat tests which affirm infection majority of the times,” said Dr Niraj Chawda, MD, Nand Hospital.

Similar cases are seen in Rajkot too. “There are a lot of cases where patients are testing negative for Covid, but CT scan reveals pneumonia. This may be happening due to limitations of sampling procedure and RT-PCR test itself which has an accuracy of about 70%,” said Dr. Jayesh Dobariya, critical care specialist in Rajkot.