A variant of H5N1 bird flu that has circulated widely in wild birds — and in several instances led to severe illness in humans — has turned up in dairy cattle for the first time. The findings were relayed in a short update from the USDA, which traced the new variant back to dairy herds in Nevada. The variant, known as D1.1 genotype, belongs to a different genetic lineage than what's fueled the infections in dairy cattle over the past year. Scientists believe a single spillover event, from birds to cattle, in the Texas Panhandle in late 2023 seeded the nationwide outbreak. But this new finding points to at least one additional instance of the virus hopping into dairy cattle.
