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.