BENGALURU: Fresh Covid-19 cases and the case load may be down in the state and the situation may appear better. But experts have cautioned against assuming that the second wave is waning unless the test positivity rate (TPR) falls below 5 per cent and mortality rate below 1 per cent. This will be known in about two weeks, they said, pointing out that the virus variants have not weakened and are here to stay.
Experts said as SARS-CoV-2’s Delta (B.1.617) and the other variants are here to stay, if people fail to follow Covid-19 safety norms, cases could rise again.“Due to restrictions and lesser movement of people, cases are down. But there is no indication that variants have lost their infectiousness. After unlocking, if people continue to be irresponsible, variants will definitely infect people and there will be more cases,”Dr V Ravi, virologist and member of state Covid Expert Committee, told The New Indian Express.
Dr Giridhar Babu, epidemiologist at the Indian Institute of Public Health, Bengaluru, said, “The variants will continue to exist. We cannot say their virulence is down. In every pandemic, there is an increase in infection and the cases drop after a certain period. It depends on how the situation is handled, and on people’s behaviour.”
He said the correct indicator of whether the second wave is on the wane is to conduct high number of tests and see how many turn up positive. A good sign is when TPR falls below 5 per cent. At present, it is 8.81 per cent in the state.Dr Pradeep Banandur, member, Covid-19 Technical Advisory Committee (TAC) and Additional Professor, Department of Epidemiology, NIMHANS, said in two weeks it would be clear whether the second wave is waning. The reproduction number (or R-Naught) — the indicator of infection — should be below 1.1. It is 1.8 now.
Dr M K Sudarshan, TAC chairman, said the second wave is expected to end by June-end. But some districts are seeing high cases, including Bengaluru Urban, Mysuru, and Tumkuru districts.“We need to observe stricter lockdown until daily caseload in Karnataka falls below 5,000, the case fatality rate goes below 1% and test positivity rate under 5% per cent. Districts with higher caseload need stricter curbs and situation should be reviewed regularly,” he said.Dr Banandur said, “We need to look at smaller containment zones instead of enforcing a statewide lockdown. The government has done its bit by increasing tests to 1.2-1.3 lakh per day. Now it is up to the citizens to consolidate the lockdown gains.”