Samples of Covid positive patients were taken between November 25 and December 23 from five districts of Delhi. The researchers identified clusters to find out how Omicron spread and then confirmed eventual community transmission.
A study into Delhi Covid samples between November 25 and December 23 last year has indicated that there was an eventual community spread of the Omicron in the Capital. Delhi health minister Satyendar Jain already claimed that Omicron was spreading in the community as people without any travel history were getting positive for Omicron, the variant which has caused the surge in Covid-19 cases in India. However, the report by the department of clinical virology, Institute of Liver and Biliary Sciences, New Delhi, is the first report confirming community transmission of Omicron in Delhi, news agency ANI said.
“The respiratory specimen of all RT-PCR confirmed positive cases between November 25 -December 23, 2021, collected from five districts of Delhi were subjected to whole-genome sequencing. Complete demographic and clinical details were also recorded. Hence, we analysed the formation of local and familial clusters and eventual community transmission,” the study noted. It found that around 60.9% of the Covid-infected people whose samples were tested showed a community spread.
“Out of the 264 cases during this study period, 68.9 per cent (n=182) were identified as Delta variant and its sub-lineages while 31.06 per cent (n=82) were Omicron variant with BA.1 as the predominant sub-lineage (73.1 per cent),” the study said.
What is community transmission?
SARS-CoV-2 is a virus that spreads from one person to another. The source of the infection thus can be tracked by retracing the people an infected person met in the last few days. This is the standard way of contact tracing as being practised by the administrations. Community transmission is not a new concept. It implied a massive spread of the infection where the source can’t be tracked as the virus is widespread in the community. It is a situation when it is not possible to track who gave the infection to whom as everybody, more or less, has the infection.
During the peak of the second wave of the pandemic too, experts claimed that without community transmission the massive second wave was not possible.
With Omicron, the issue of community transmission became evident as people without travel history tested positive of this variant. Omicron was first found in South Africa in November 2021. The first cases were reported in India in December. The first few cases were reported in people coming from abroad. The period in which the samples in Delhi have been studied was the time when Omicron’s spread was accelerating.