islamabad-Viral genome sequencing of wastewater can detect new SARS-CoV-2 variants before they are detected by local clinical sequencing, according to a new study reported in mBio, an open-access journal of the American Society for Microbiology.
The ability to track SARS-CoV-2 mutations in wastewater could be particularly useful for tracking new variants, like the B.1.17 strain that is now widespread in the U.K. and has already been introduced in the U.S. “SARS CoV-2 virus is excreted by individuals that are infected by COVID -19and the fecal waste ends up in the wastewater systems.
By sampling wastewater, we can get information on infections for a whole population. Some wastewater systems serve several thousand people. Some serve hundreds of thousands of people,” said principal study investigator Kara Nelson, PhD, professor of civil and environmental engineering, in the College of Engineering at the University of California-Berkeley. “Sampling wastewater is a very efficient way to get information.
It is also a less biased source of information, because 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.” In the new study, researchers developed and used a novel method for sampling wastewater.
When researchers sequence RNA concentrated and extracted from wastewater samples, there may be many different strains present because there are many individuals contributing to the sample. However, it is challenging to distinguish the SARS-CoV-2 genetic signal from the billions of bacteria and viruses people excrete every day. Researchers must identify SARS CoV-2 amidst a whole soup of other genomic material.