MUMBAI: The more accurate RT-PCR test is now the predominant testing method used in the state. Data accessed by TOI shows that the use of RT-PCR was as high as 71%-73% on February 20 and February 21. Till December and most of January, the share of RT-PCR (50%) was as much as that of the rapid antigen test (50%), which though quicker is known to be less accurate.
A Central team that visited Maharashtra a few weeks ago had directed that testing numbers should be increased drastically, including that of RT-PCR tests. In certain districts, over 70% of the tests were done using rapid antigen. Data showed that on February 20, of the 65,962 tests, 46,842 were done using RT-PCR. The data for February 21 too showed that 73% of the 48,141 tests carried out in the state on that day was using RT-PCR. The share of antigen has been reduced to 30% on most days.
A senior state official said that districts have been asked to push up RT-PCR numbers following the spurt in cases. “As it is, no district was encouraged to use too much antigen, but because of the ease, it was preferred over RT-PCR. The turnaround time for RT-PCR remains 24 hours, and that tempts many to opt for antigen,” the official said. The dependence on antigen tests had vastly increased around August and September, when up to 55% tests were done using this method. The state, however, did a course correction soon after. The public health department had released a testing algorithm on August 21, spelling out the use of three testing modalities—RT-PCR, rapid antigen and TrueNat/CBNAAT— for different categories of patients and population. It stated that patients coming to hospitals with severe acute respiratory infection (SARI) or influenza-like illnesses (ILI) and in need of immediate hospitalisation should be tested with the antigen test that gives an outcome in 30 minutes.
In Mumbai, AMC Suresh Kakani said 70% of tests are now done using RT-PCR. “Even as we push up testing numbers, the emphasis will be on RT-PCR,” he said. However, in the more interior districts, the RT-PCR scale-up could take a while. Dr Anil Rudey, civil surgeon of Gadchiroli, said they can test up to 100 samples a day in the sole RT-PCR lab. “We are looking at ways to scale up,” he said. In Amravati, one of the districts worst hit in the February surge, civic surgeon Dr Shyamsundar Nikam said they are currently using antigen mainly for mass testing in hotspots.