CHENNAI: As
Tamil Nadu added 2,089 new cases on Saturday, the weekly average of daily cases which was around 486 on February 27, went up to 1,655 on Saturday — almost a four-fold jump over the past 30 days.
Though in February this year the directorate of public health had said that at least 31.6% people in Tamil Nadu had developed antibodies for Sars-Cov2 by November 2020 with an estimated 22.6 million infections, the ‘herd immunity’ seems to have had little impact in curtaling the second surge in the state.
Over the same 30 days, as per TOI analysis, the doubling period the time taken for cases to double from their current level dropped from 1,267 days to 352 days, indicating a steep rise in infection spread.
According to experts, it would be difficult at this stage to predict when active cases would hit a peak before they start coming down.
“Going by the trend, we only know that the 31% sero positivity rate had made little difference to the spread of infection,” said National Institute of Epidemiology deputy director Dr Prabhdeep Kaur.
While nine deaths on Saturday took the state toll to 12,659, total cases in the state was 8,88,279. Currently, 12,157 people were undergoing treatment for the infection across the state.
“We continue to see up to 10% positivity rate in clusters and high positivity rate in urban areas. Last year, we were able to slow down transmission with lockdowns. Now, with no restrictions on crowds and with elections around the corner, conventional tools such as testing, isolation, use of masks and social distancing, will be the only means to pull down the epidemic curve,” Dr Kaur said. She also said more people should be encouraged to take vaccine. “But the effect of the vaccine will be seen only after two weeks of the second dose,” she added.
Public health officials say they don’t have data on the number of people coming with reinfection or those who have been infected after two doses of the vaccine. Also, the state is still awaiting results of samples it sent from clusters for genetic testing. “We still don’t know if the virus in circulation is an ‘escape’ mutant,” said senior epidemiologist Dr Jayprakash Muliyil. Escape mutants are variants that will infect people who have already had the infection. “We see newer zones in cities and villages getting affected,” he said.
For instance, in Chennai this year, Central and Southern zones are seeing higher numbers of cases compared to zones in the north last year. “We will need more days to confirm this. We may also have to wait for some more time to see if this wave will be more morbid and fatal compared to last year,” he said.
On Saturday, Chennai reported 775 new cases and four deaths, the three adjoining districts Chengalpet (186), Tiruvallur (104) and Kancheepuram (82) together added 378 cases. Together the four districts had 55% of new cases and 57% of fresh cases in the state.
Meanwhile, with 185 new cases, Coimbatore had the third highest number of cases after Chennai and Chengalpet. While Thanjavur had 66 new cases, Tiruppur had 59, Salem and Nagapattinam and 55 and 51 cases respectively. While all districts reported new cases, eleven districts reported fresh cases in single digits.