Continued selection on cryptic SARS-CoV-2 observed in Missouri wastewater

by Devon A. Gregory, Clayton Rushford, Torin Hunter, Chung-Ho Lin, Christie Darby, Nicole Niehues, Elizabeth Semkiw, Melissa Reynolds, Jeff Wenzel, Marc C. Johnson

Deep sequencing of wastewater to detect SARS-CoV-2 has been used during the COVID-19 pandemic to monitor viral variants as they appear and circulate in communities. SARS-CoV-2 lineages of an unknown source that have not been detected in clinical samples, referred to as cryptic lineages, are sometimes repeatedly detected from specific locations. We have continued to detect one such lineage previously seen in a Missouri site. This cryptic lineage has continued to evolve, indicating continued selective pressure similar to that observed in Omicron lineages.