The US Department of Agriculture (USDA) has announced a new outbreak of the highly pathogenic H5N1 avian flu virus among dairy cattle, with the D1.1 genotype detected in Nevada milk samples. This is the first time the D1.1 genotype has been found in dairy herds, which had previously only reported infections from the B3.13 genotype.
According to the USDA, the new outbreak involves a significant spillover of the virus into domestic poultry and other animals, with cases linked to human infection also reported. Wild birds, mammals, and domestic poultry have all been affected by the D1.1 genotype, which has been identified in several states, including Nevada.
The detection was part of an investigation following four recent H5N1 detections in Nevada dairy herds. The state’s agriculture officials are removing large flocks of European starlings, a non-native species that can spread diseases to livestock, as a measure to curb the virus’s spread.
Experts say the new outbreak highlights the ongoing risk of H5N1 avian flu and emphasizes the need for continued vigilance. “We shouldn’t be surprised about a new spillover to cattle,” said University of Minnesota epidemiologist Michael Osterholm. The USDA is working with Nevada officials to better understand the detection and limit further spread, while also publishing a technical brief on the findings in the coming week.
Source: https://www.cidrap.umn.edu/avian-influenza-bird-flu/usda-confirms-spillover-2nd-h5n1-avian-flu-genotype-dairy-cattle