A dairy cow in Maricopa County, Arizona, has tested positive for the D1.1 genotype of bird flu, prompting quarantine measures on the affected farm. The Arizona Department of Agriculture (AZDA) confirmed the finding, marking the first detection of this particular strain in milk from an Arizona dairy herd. While the affected cattle show no symptoms, the positive test result triggered immediate action. The AZDA has assured the public that pasteurized milk and dairy products remain safe for consumption.

This incident follows a similar case in Nevada earlier this year, where the same D1.1 genotype was identified in dairy cattle. Previously detected cases in dairy cows involved a different genotype, B3.13. The D1.1 strain is currently the most prevalent genotype in North American bird migration routes and has been found in wild birds, mammals, and domestic poultry. Although the AZDA stated this genotype doesn't pose an increased risk of human infection, the new D1.1 strain has been reported in over a dozen people who had contact with infected poultry. Despite these instances, the CDC maintains that the overall risk of bird flu to the general public is low.