Omicron ruled out in one international flyer, 67 city samples

Nagpur: In an assuring development for the city, genome sequencing has revealed the presence of only Delta and Delta sub-lineages as the dominant variant in Nagpur so far. The study by CSIR-Neeri’s environmental virology cell has ruled out Omicron variant (B1.1.529) in any of the 68 samples.
The Delta variant (B1.617.2), declared variant of concern, was found to be behind acceleration in cases during the second wave which began from Nagpur and Amravati in March this year. Though the variant caused severe Covid disease then, now patients remain mild.
The city’s only officially documented Omicron positive patient is now discharged. As per Pune-based NIV’s report, the patient was found Omicron-like yet officials have counted him as Omicron positive.
The 68 samples belong to Covid patients, including one international flyer, who tested positive between November-end and December 18. All the 68 samples belong to vaccinated patients.
Another 35 samples from the same period are under process, said Dr Krishan Khairnar, head of the cell. As per civic officials, among the 35 samples, 17 persons are vaccinated and 18 unvaccinated.
The environmental virology cell has now performed genome sequencing of 852 samples since October 2020.
“Of the 68 samples, 11 were taken from close contacts of the international passenger. All of them were Delta positive. The samples were processed in a week by CSIR-Neeri in collaboration with CCMB Hyderabad. The study shows that Delta is still the dominant variant in Nagpur,” said Dr Khairnar.
The scientist cautioned that the threat of Omicron is serious. “If Covid-apt behaviour is not followed, then it is a matter of time that Omicron may replace Delta as the dominant strain,” he said.
On whether a sample size of 68 was enough to rule out any other variant, Dr Khairnar said, “We are in the best position to say this. At one time, only 5% of total samples were studied. Now, since positivity is low, we are sequencing samples of all daily Covid patients. Nagpur is the only city which is sequencing all positive samples,” he said.
He reiterated that amid the threat of various variants, the best defence against the virus is SMS (sanitising, masks and physical distancing). “It will remain effective during the pandemic,” he said.
The cell has been sequencing all daily Covid positive samples from Nagpur since June. However, the cell has been involved in SARS-COV-2 sequencing of Nagpur samples since October 2020.