Although COVID-19 patients in the past were asymptomatic, patients identified with the recently discovered proportion of SARS-CoV-2 samples exhibit symptoms and have a higher risk of developing pneumonia as a result of several complications, Head of the National Centre for Primary Care and Allergy Research at the University of Sri Jayewardenepura, Dr.Chandima Jeewandara said yesterday (26).
“We have described and reported the B.1.411 lineage (Sri Lankan lineage) is the predominant SARS-CoV-2 virus strain in Sri Lanka currently. However, we have observed a rapid increase in the proportion of SARS-CoV-2 samples with undetectable S-gene target (S-gene target failure, SGTF) for some real-time RT-PCR testing methods,” he said.
“Deletion of amino acids 69 and 70 within the spike (S) gene of SARS-CoV-2, sometimes attributable to the N501Y mutation, can result in SGTF. SGTF was identified in regions of England affected by B.1.1.7, and, after validation with whole-genome sequencing, SGTF was determined to be a reliable marker of B.1.1.7. Further, the E484K mutation, an escape mutation, is known to occur independently de novo in areas of high transmission, also described in our lineage recently.
E484K mutations have been identified in B.1.351 and B.1.1.28 variants, and it appears to threaten the efficacy of vaccines. Hence, it would be essential to carry out a mutation analysis to investigate the emergence of E484K mutation in SARS-CoV-2 virus strains circulating in Sri Lanka.”
Dr. Jeewandara said that PCR kits were recently developed for full screening for SARS-CoV-2 and variants, including the five notable mutations in the S gene. This method is far cost-effective and rapid in detecting the emergence of mutation and new variants, he added.
Speaking further, Dr.Jeewandara said the public should strictly adhere to COVID-19 prevention guidelines.
“Everyone should wear facemasks frequently and avoid gatherings which are not important. If the public adhere to the guidelines and behave responsibly, we would be able to control this newly erupted situation soon,” he pointed out.
(Source: Ceylon Today – By Dilanthi Jayamanne, J.T de Silva and Savani Sheshadhi)