The State has been maintaining a test positivity rate (TPR) of less than one percent for the past one month. From 1.1% on December 25, the State’s average (TPR) reduced to 0.9% since the beginning of January and has continued to remain as low as 0.7% in the past 15 days.
While this has brought cheer to the State, which had been expecting a second wave this month, it is not yet an indication of tiding over the crisis, experts said.
“We can claim to have sustained the flattening of the curve only if the trend of less than one percent TPR continues till March-April,” said C.N. Manjunath, nodal officer for labs and testing in the State’s COVID-19 task force.
Going by the exponential rise in the number of COVID-19 cases in countries such as Britain and France nearly five months after cases drastically reduced, the State should keep its fingers crossed till March-April, he said.
While the State was reporting more than 10,000 new cases till mid-October, cases came down to around 5,000 after that. From November first week, new cases reduced to less than 5,000 and further reduced to less than 2,000 from December. From mid-December, cases reduced to less than 1,000 and have been further going down.
Giridhar R. Babu, member of the State’s Technical Advisory Committee (TAC), said the low numbers could be because the threshold for population immunity has been reached in most dense urban areas.
“As long as there are pockets of susceptible people and as the vaccine has not yet been rolled out for the general population, it will not be safe to say we have herd immunity as yet,” Dr. Babu said.
“Testing should continue on a syndromic approach even when there is no surge. Ideally, for every case detected, 10 persons (contacts) should be tested,” he said.
No change in testing strategy
V. Ravi, former senior professor and head of neurovirology at NIMHANS who is also a part of the TAC, said there should be no change in the testing strategy till March-end. “We will get the second sero survey results by then, and we will know the extent of population that has already been exposed to the virus. We can review the situation after that, but till then, we should continue testing the same number of people,” he said.
Meanwhile, the number of daily tests conducted in the State has reduced in the last few days. While an average of over one lakh tests were being conducted every day, the number has come down to an average of 80,000. On Wednesday, the number of tests was 58,695.
Dr. Manjunath said keeping up the same pace of testing has become a challenge. “Even if the target of testing symptomatic, high-risk and primary contacts remains the same, it is difficult to find more contacts as the number of new cases detected is coming down. But, it is important to continue the same level of testing based on syndromic approach at least till March,” he added.