Alarm bells ringing: Omicron in community transmission stage in India, says INSACOG

Alarm bells have started ringing after Indian SARS-CoV-2 Consortium on Genomics (INSACOG) on Sunday said Omicron is now in the community transmission stage in India.

In its two-page bulletin, INSACOG said Omicron has become the dominant variant in multiple metros, where new cases have been rising exponentially. While most Omicron cases so far are asymptomatic or mild, hospitalizations and ICU cases are increasing in the current wave, it said.

An infectious sub-variant of Omicron, BA.2, has been detected in a considerable fraction in India, it said. "BA.2 lineage is a substantial fraction in India and S-gene dropout-based screening is thus likely to give high false negatives. Tests suitable for PCR-based screening applicable to all Omicron lineages have been approved for use," it said.

INSACOG, jointly initiated by the Union Health and Family Welfare Ministry, the Department of Biotechnology, and others, is a consortium of 38 laboratories monitoring the genomic variations in SARS­CoV­2, the novel coronavirus causing COVID­19. The recently reported new SARS­CoV­2 variant — B.1.640.2 — lineage was being monitored, it added and said there was no evidence of rapid spread and while it had features of immune escape, it was currently not a variant of concern. "So far, no case detected in India," the bulletin said.

BA.2 lineage, it added, was a substantial fraction in India and S­gene dropout-based screening was thus likely to give high false negatives. Tests suitable for PCR-based screening applicable to all Omicron lineages had been approved. S­gene drop­out was a genetic variation like that of Omicron.

"Further spread of Omicron in India is now expected to be through internal transmission, not foreign travelers, and a revised sampling and sequencing strategy of INSACOG is being worked out to address genomic surveillance objectives in the wake of dynamic changing scenario of virus infection," the bulletin added.