New Delhi: Most patients infected with the Omicron variant of COVID-19 in the last week of December 2021 had no travel history, indicating that there was possible community transmission, according to the study conducted by the Department of Clinical Virology, Institute of Liver and Biliary Sciences, New Delhi.
“Respiratory samples of all positive cases confirmed by RT-PCR between November 25 and December 23, 2021, collected from five districts of Delhi, were subjected to whole genome sequencing. Full demographic and clinical details were also recorded. Therefore, we analyzed local and family cluster formation and possible community transmission,” the study notes.
The study also indicates that about 60.9% of people infected with COVID-19 showed community spread.
“Of the 264 cases during this study period, 68.9% (n=182) were identified as the Delta variant and its sublineages, while 31.06% (n=82) were the Omicron variant with BA.1 as the predominant sublineage (73.1%),” he continues.
He said most Omicron cases were asymptomatic (n=50.61%) and did not require hospitalization.
“A total of 72 (87.8%) cases were fully vaccinated. About 39.1% (n=32) had a travel or contact history while 60.9% (n=50) had community transmission,” he added.
The study shows a sharp increase in the daily progression of Omicron cases with its prevalence in the community which has been observed from 1.8% to 54%.
According to the interpretation of the study, it is one of the first in India to provide evidence of Omicron community transmission of coronavirus infection with significant increase in breakthrough infections, decrease in rates hospitalization and a lower rate of symptomatic infections in people with high seropositivity versus SARS-CoV-2 infections.