On Dec. 4 2023, the University of Wisconsin-Madison researchers announced that while analyzing data from wastewater samples collected by the Wisconsin State Laboratory of Hygiene earlier this year, David OﾒConnor and his colleagues detected a highly mutated version of the virus that causes COVID-19 called a cryptic lineage. With some careful scientific sleuthing, they were able to track the lineage to a single source.

Whatﾒs curious about cryptic lineages is that, through some unknown process, they develop the same spike gene mutations found in variants of concern, like omicron, despite not being descended from these or related strains. Scientists are interested in studying these lineages, which might be the origin of the next major COVID variant and a widespread wave of infection. Their findings were the subject of a study published ahead of peer review on Nov. 1 in medRxiv.