New Delhi:Given the pandemic resurgence fears on account of new mutant coronavirus strains, WHO has asked all countries to expedite the genomic sequencing of SARS-CoV-2. These concerns come in the backdrop of covid-19 cases decreasing globally by 16% over the last one week.
However, WHO is seeing a fresh challenge of mutant coronaviruses spreading across the world, and has called for a minimum of 15 samples per week from sentinel surveillance systems. It also wants genetic sequence data sharing through a publicly accessible database.
The apex global public health agency on Wednesday also issued the operational considerations to expedite genomic sequencing component of Global Influenza Surveillance and Response System (GISRS) surveillance of SARS-CoV-2.
“Genomic sequencing of pathogens helps understand epidemiology and transmission, tracks evolutionary changes, and informs the development of diagnostics and vaccines,” said Soumya Swaminathan, Chief Scientist WHO.
The WHO has said that the countries should move beyond virus detection to genomic sequencing of SARS-CoV-2 PCR positive materials obtained from sentinel surveillance of influenza-like illness (ILI), acute respiratory infection (ARI) and severe acute respiratory infection (SARI).
In its latest update on the COVID-19 pandemic, the WHO said that although the number of global infections has fallen by 16% in a week – 500,000 fewer cases – regions, including Europe, are still in the grip of the virus whose variants are spreading. The number of coronavirus deaths also declined in all regions by 10% over the same period, with 81,000 fatalities reported in the last week.
Three main covid-19 mutations have raised concerns over faster virus transmission and also leading to eruption of doubts if the available vaccines will work on these strains, the WHO said that the UK variant is now present in 94 countries across all regions – eight more than the previous week. The “South African variant has been traced in 46 countries, an increase of two, while the “Brazilian/Japanese variant is present in 21 countries, up by six. Citing genetic sampling of the UK variant, the WHO report noted that the proportion of people infected with UK variant has increased in the past weeks, indicating community transmission in a number of countries.
India this week has also confirmed four cases of the South African strain and one Brazilian strain of the virus. India already has approximately 200 cases of the UK mutant strain circulating in the country. The Indian SARS-CoV-2 Genomic Consortia (INSACOG) is doing sentinel surveillance for early detection of variants of concern of SARS-CoV-2. It also determines the circulating strains of SARS-CoV-2 in unusual events such as high mortality, super-spreader.
The WHO asked countries to monitor the trend and prevalence (proportions) of existing and emerging (co-) circulating genetic variants (clades) among samples from sentinel sites. It further said that wherever possible, the countries should contribute to a better understanding of associations between genetic characteristics of SARS-CoV-2 and transmission scenarios and severity of covid-19 disease.
The WHO said that the selection of SARS-CoV-2 PCR-positive sentinel samples should reflect the representativeness of different age groups (e.g. 0 to <2 years, 2 to <5 years, 5 to <15 years, 15 to <50 years, 50 to <65 years, ≥65 years), different geographic locations (sentinel sites) within the country, different time points, patients representing the spectrum of disease meeting case definitions in use for ILI, ARI or SARI, clinically significant cases from sentinel surveillance (e.g. fatal cases, vaccinated individuals, immunocompromised individuals, patients receiving treatment such as antivirals, plasma therapy or monoclonal antibodies), re-infected cases.