KOLKATA:
Bengal on Tuesday reported a
positivity rate of 7.9%, the first time in more than two months that the figure has dropped below the 8% mark. Experts see it as a sliver of year-end hope in the battle against the virus, but have cautioned against letting down the guard.
The last time the positivity rate was 7.9% on September 26. It kept rising but stayed below the 8% mark till October 12. Barring this 16-day phase, a below-8%-positivity rate was last reported on August 1.
“There is a declining trend in the number of Covid-19 positive cases,” said Sanjib Bandyopadhyay, assistant professor of community medicine, who is also the secretary of the Indian Public Health Association’s Bengal chapter. “But, with a new strain being found in the UK, there should be no room for complacency. People should still stay away from mass gatherings and should stick to protective measures.”
Hospitals, too, have been reporting a dip in the number of patients seeking treatment for
Covid. But experts fear there could be a large number of missing cases because of an over-use of RAT (rapid antigen tests) and a reluctance to get tested, among other factors, for a drop in positivity.
“While the natural process of waxing and waning could be a reason, we need to rule out under-testing and under-reporting. And, because it’s winter, and with a new strain of the virus in the UK, we could also get into another wave if we do not up the ante right now,” said Sumon Poddar associate professor, in charge of the microbiology lab at the Institute of Child Health.
About nine months into the pandemic in Bengal, many people are reluctant to get tested even if they have had close contact with a positive person, unless they are symptomatic. “If there is a reduction in the number of positive cases despite the unlock, starting of public transport including local trains and mass gatherings, we must also look into the logical explanation,” said microbiologist Pratip Kumar Kundu, former director at School of Tropical Medicine, Kolkata. “Has the virus lost its virulence to some extent? Has it mutated? Have we developed herd immunity of the current strain?... If the virus has mutated, can the same kits — rapid antigen or RT-PCR — detect the new strain?”
According to state health department data from August 1 to December 22, 58.6 lakh Covid tests were conducted in Bengal, of which 30.6 lakh were RAT. In this four-and-a-half-month phase, 52.2% of all Covid tests conducted in Bengal were RAT tests.
TOI has reported that following ICMR’s revised guidelines on Covid testing, the health department asked all district magistrates and chief medical officers of health to intensify the search for missed positive cases through follow-up RT-PCR tests for all rapid antigen test negatives. The test should be done on those who had taken the rapid antigen test five to 10 days ago and those people who were symptomatic, but whose rapid antigen test reports came out negative.