THANJAVUR: Doctors at the Thanjavur Medical College Hospital, looking back on their handling of the pandemic, observed that 18 per cent of the cases were clinically positive but their PCR tests were negative. Of the 1,100 people treated for Covid-19, 200, or 18 per cent, tested negative for the virus in RT-PCR test but diagnosed based on clinical symptoms.
This is one of the key insights gained, nearly seven months after the pandemic reached Tamil Nadu. While the hospital’s virology lab, which opened on April 13, completed 2 lakh tests on October 1, doctors have started to look beyond the ‘gold standard’ PCR test results. Dr S Marududurai, hospital dean, told TNIE that CT scan of patients was being scrutinised alongside PCR test results to detect the infection.
“Results from all centres, including private labs, in the district are being collected and analysed for symptoms,” he said. According to him, 60 per cent results suggested suspected Covid pneumonia. Further, he said that there was a rise in the percentage of patients with suspected Covid pneumonia symptoms. “The number of people with mild score in the CT scan result was 21 in July.
This increased to 286 in September. Similarly, the number of people with a moderate score was zero in July but reached 175 in September,” he said. The number of patients with severe score rose from 11 in July to 126 in September, which suggested that patients may be waiting for too long to access medical help, Marududurai inferred. Even as doctors are reading PCR results alongside CT scans to diagnose Covid, the lab has been working round the clock from day 1.
“The team, led by an associate professor, seven assistant professors, 13 lab technicians and three data entry operators have been working without break,” he said. So far, eight of the lab staff tested positive for Covid and recovered. The lab has two rapid extracting machines, one given by the ICMR and the other by the State government, besides three RT-PCR test machines.
“Thanjavur has been in the top five districts as far as the number of tests conducted,” Marududurai said, adding 82,237 tests per million population were conducted, which is higher than the State and national average. Although the district has reported hundreds of cases each day, the positivity rate is 5.2 per cent. The tally stands at 11,650 of which 1,746 are active cases.