Genome sequencing of sewage water can help discover new coronavirus variants: US scientists

Researchers from the University of California (UC)-Berkeley have also developed and tested a novel method for sampling wastewater to study the evolution of the novel coronavirus.

By: Longjam Dineshwori | | Updated: January 21, 2021 11:10 am

SARS CoV-2 excreted by those infected by COVID-19 ends up in the sewage water.

The emergence of more transmissible and more contagious coronavirus strains has raised alarm, prompting new lockdowns in some countries. For example, a new variant of the virus, known as B.1.1.7, is spreading rapidly in the UK and it has also been detected in several countries, including India. With the virus mutating rapidly, medical professionals across the world are debating on whether current vaccines will be effective against the new strains. Even WHO Emergencies Executive Director Dr Mike Ryan had cautioned that the second year of COVID-19 pandemic could be tougher, given the emerging variants of SARS-CoV-2 and their transmission dynamics. Therefore, the organisation has stressed the importance of improving genomic sequencing in order to identify and respond to new variants early on. Also Read - Akshay Kumar, Piyush Mishra, Sonam Kapoor and more Bollywood celebs who opened up on facing sexual abuse in childhood

Echoing the same, US scientists are suggesting examining of sewage water for new coronavirus variants. Kara Nelson from the University of California (UC)-Berkeley and her team are of the opinion that viral genome sequencing of wastewater can help discover new variants before they are detected by local clinical tests, according to a PTI report. Also Read - Test Article 2 Covid 19 3rd wave

Nelson explained that as SARS CoV-2 excreted by individuals who are infected by COVID-19 ends up in the sewage water, sampling wastewater can provide information on infections for a whole population. Also Read - COVID-19 Live Updates: Cases in India surge to 10,757,610 while death toll reaches 1,54,392 12d

“We can get information from all individuals in the sewershed, whether or not they are being tested in a clinic. We know that there are individuals that have asymptomatic infections that may never get tested,” Nelson was quoted as saying in a research paper, published in the peer-reviewed journal mBio.

New method for sampling wastewater

While sampling wastewater is an effective way to get information on the evolution of the novel coronavirus, the scientists acknowledge that distinguishing the SARS-CoV-2 genetic signal and its RNA from the billions of bacteria and viruses present in fecal waste is a difficult task. To make the process easier, Nelson and her team have developed and tested a novel method for sampling wastewater.

Rather than directly sequencing everything present in the wastewater samples, their new approach first focusses on enriching the viral RNA. Then they use a novel bioinformatic analysis approach that was sensitive enough to detect a single nucleotide difference, as explained by Nelson.

Using their new method, the scientists sequenced viral RNA from sewage collected by municipal utility districts in the San Francisco Bay Area and generated whole and nearly complete SARS-CoV-2 genomes. Interestingly, the common SARS-CoV-2 genotypes detected in the sewage were found to be identical to clinical genomes from the region. They also discovered new variants with very small differences in the genetic material that had only been reported from elsewhere in the US or globally.

On the basis of their findings, Nelson and her team suggested that wastewater sequencing can provide evidence for new viral lineages before clinical sequencing.

Some new variants are associated with increased transmissibility, but so far, they are not found to cause disease severity, the article noted.

The WHO is also expanding its scientific collaboration and monitoring of emerging variants of SARS-CoV-2. In an article posted to its website on January 12, the organization said that some new variants are associated increased transmissibility, they don’t seem to cause disease severity.

Published : January 20, 2021 2:13 pm | Updated:January 21, 2021 11:10 am

Covid-19 vaccination: Concerns about adverse effects ‘unfounded, negligible’, says Govt

'Game changer against Covid-19': Expert panel recommends phase 1 trial of Bharat Biotech's nasal vaccine

About The health Site

Useful Links