Omicron probably behind case spike in Delhi, shows analysis

Between December 21 and 28, the Institute of Liver and Biliary Sciences (ILBS) analysed 125 samples, of which 67 were of the Omicron variant.

More than half of the Covid-19 samples analysed in the last seven-day period by one of Delhi’s main hospitals carrying out genome analysis are of Omicron, according to data accessed by HT, which suggests the surge in cases in the city is being driven by the new variant of concern (VOC).

A healthcare worker takes a nasal swab sample of a passenger for the Covid-19 test at Kashmere Gate ISBT. (ANI)

Between December 21 and 28, the Institute of Liver and Biliary Sciences (ILBS) analysed 125 samples, of which 67 were of the Omicron variant. A person aware of the matter said the samples were from labs in different parts of the city, suggesting the virus may be in community transmission.

“These positive samples were taken as part of sentinel surveillance as Delhi government has now decided to sequence all samples that test positive for Covid-19. We were suspecting it to be Omicron even before the whole genome sequencing results came as doubling time has been around 3 days, and Delta was not spreading this fast,” said a person familiar with the development, asking not to be named.

This person said that based on the experience of other countries where the VOC has spread, cases will rise, perhaps peaking around the end of January, before the wave recedes sharply. “It looks it will subside soon after, and people should not panic. We are a Delta-infected community with 100% coverage of first Covid-19 vaccine dose; therefore, disease is likely to be less severe,” this person said.

The documents seen by HT included sequencing results from the National Centre for Disease Control and Lok Nayak hospital. It was not immediately clear what proportion of these were community samples since they also sequence samples from international travellers who test positive.

At NCDC, a total of 263 samples were analysed out of which Omicron was found in 101, Delta variant in 27 samples, while the rest were unclassified. At Lok Nayak hospital, of a total 80 samples analysed, 12 were of Omicron while 62 were of the Delta variant.

Dr Suresh Kumar, medical director of Lok Nayak hospital, said the laboratory at the hospital has the capacity to analyse 100 samples in a day. “The capacity of the laboratory has been recently increased. Earlier the laboratory was able to analyse only around 40 samples in a day,” Kumar said.

Dr Kumar said that since December 2 a total of 70 Omicron patients have been admitted to Lok Nayak hospital, out of which 50 have been discharged after treatment and 20 are currently admitted. “All had international travel history or were common contacts of those who arrived from abroad except two persons who apparently got infected at some wedding parties,” said Dr Kumar.

Apart from Lok Nayak, Delhi has four private hospitals that have set up Omicron isolation units. Delhi government on December 18 asked Max Smart Super Speciality Hospital, Saket; Batra Hospital & Research Centre, Tughlakabad Institutional Area; Fortis Super Specialty Hospital, Vasant Kunj; and Sir Ganga Ram City Hospital for institutional isolation facility for Omicron patients.

Experts said it is clear that the variant was in circulation within the community because of the way numbers are escalating.

“It is already there; we have been genome sequencing less samples, if we did more then, the number would go up further. The way number of cases are going up, it couldn’t be the delta variant. However, preventive measures remain the same- masking-up, vaccination, following other Covid appropriate behaviour,” said Dr GC Khilnani, former head, pulmonary medicine department, All India Institute of Medical Sciences, Delhi.