One case of BA.4 sub-lineage of Omicron reported in TN

CHENNAI: One case of SARS COV-2 Omicron Variant - BA.4 Sub Lineage has been reported In Tamil Nadu based on the initial whole genomic sequencing report. The officials from the State Public Health Laboratory, Chennai confirmed the same but the result from other laboratories under the Indian SARS-CoV-2 Consortium on Genomics (INSACOG) is awaited.

As per the current testing protocol, community clusters, family clusters, re-infection, children, and samples from severely ill patients were prioritized for whole genomic sequencing to look for the emergence of new variants.

A release from the Directorate of Public Health and Preventive Medicine said that the clusters at IIT Madras and Sri Sathya Sai Medical College were due to BA.2 variant of Omicron only. A total of 3,328 samples have been subjected to sequencing from January to May 2022 and 96 percent of the variants belongs to Omicron only. BA.2 is the predominant variant reported in 73 percent of the samples sequenced. BA.1 sub-lineages are also being reported to some extent in Tamil Nadu.

Recently, one case of BA.4 was reported in Tamil Nadu. The sample of 19-year-old female from a family of four, including father, mother, daughter and grandmother residing in a gated community at Navalur, OMR had the BA.4 subvariant. Three of them including the two positive persons are fully vaccinated with 2 doses of vaccine while the grandmother had taken one dose of vaccine.

The initial symptoms of flu-like illness were reported in a 45-year-old mother and 19-year-old daughter on May 4, 2022, and were tested positive for COVID-19. They were self-isolated in their house and recovered within 3 days of their illness.

There was no travel history but their samples were sent to State Public Health Laboratory and were sent to NEERI, Nagpur for sequencing. As per the reports obtained on Thursday, both were caused by Omicron variant of SARS COV-2 only in which the mother had BA.2 sub-lineage and the daughter had BA.4 variant.

Health Secretary J Radhakrishnan, the Deputy Director Health, Chengalpattu and the Block Medical Officer, Kelambakkam visited the family and they are doing well. There were no new cases reported in their community and close contacts, a release from the Directorate of Public Health and Preventive Medicine said.

The confirmation is awaited at the national level by NCDC, the officials from the Directorate of Public Health and Preventive Medicine say that the identification of the BA.4 Omicron Sub-variant is not a cause of any immediate panic, it is more a reminder to continue the focus on eligible persons getting completely vaccinated and the need to continue to follow COVID-19 appropriate behaviour in crowded areas. The state is adequately prepared to tackle any situation.