Omicron in community transmission in India, threat level unchanged: INSACOG

Omicron is in community transmission in India and has become the dominant variant in multiple metros where new cases have been rising exponentially, the Indian SARS-CoV-2 Genomics Consortium (INSACOG) has said.

In its latest weekly newsletter dated January 10, the genomic consortium said that while most Omicron cases have so far been asymptomatic or mild, hospitalisations and ICU cases have been increasing in the current wave. “The threat level remains unchanged,” the consortium has cautioned.

The World Health Organisation (WHO) defines community transmission as “outbreaks with the inability to relate confirmed cases through chains of transmission for a large number of cases, or by increasing positive tests through sentinel samples — routine systematic testing of respiratory samples from established laboratories”.

In other words, a pandemic reaches the community transmission stage when it is not possible to trace the source of infection in a large part of the population back to any carrier who might have caught the virus through another contact or by travelling to an affected area. This means, anyone can catch the contagion.

While the health ministry has not used the term community transmission to describe the stage of Omicron infections in India, INSACOG’s statement means that utmost precautions in terms of mask wearing, social distancing and avoiding crowding have to be enforced.

For instance, Delhi, which currently has weekend curfew in place, had requested the Lieutenant Governor to lift these restrictions as the number of cases is falling and hospitalisations are low. The request was rejected.

Globally, the Omicron variant has been seen to have a lower rate of hospitalisation compared to the second wave caused by Delta due to intrinsically reduced severity with lesser propensity to cause pneumonia as also due to higher population immunity.

INSACOG, however, noted in its newsletter that due to the very high number of cases, the absolute number of hospitalisations has crossed previous highs in many countries and is creating stress on healthcare systems. It also said that global data so far suggests that the majority of severe cases and deaths have been in unvaccinated subjects, with high protection associated with vaccination or previous infection.

“While deaths have been much lower during the new wave, compared to previous waves, there have been Omicron-associated deaths,” INSACOG said.

The consortium also said that tests suitable for RT-PCR-based screening applicable to all Omicron lineages have been approved for use.

Meanwhile, the recently reported B.1.640.2 lineage, identified in France, has not been detected in India so far. It has not been classified as a variant of concern yet. Scientists at INSACOG have said that the variant is being monitored and while there is no evidence of rapid spread, this mutation has features of immune escape.  

So far, 72 per cent of all samples sequenced through INSACOG have been found to be of a Covid-19 variant — Pangolin lineage, including Alpha, Beta, Gamma, Delta, Omicron. Rising cases and the positivity rate in six states — Maharashtra, Karnataka, Tamil Nadu, Kerala, Delhi and Uttar Pradesh — have been of concern.