Scientists in New York City have repeatedly detected "cryptic lineages" of the coronavirus in wastewater samples for the past year, The New York Times reported Feb. 3.
Researchers first identified the viral fragments in the city's wastewater last January, according to findings published Feb. 3 in Nature Communications. The lineages have a unique mix of mutations never before seen in humans, suggesting the presence of a new variant.
The lineages have been circulating for at least a year without overtaking delta or omicron as the nation's dominant strain, and there are no signs they pose a greater risk to human health, according to the Times.
Researchers say the lineages' origins are still unclear.
"At this point, what we can say is that we haven't found the cryptic lineages in human databases, and we have looked all over," study author Monica Trujillo, PhD, a microbiologist at New York City-based Queensborough Community College, told the Times.
Researchers said it's possible these lineages come from humans with COVID-19 whose virus samples are not being genetically sequenced. Another hypothesis is that the lineages may stem from animals infected with the virus.
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