Iowa authorities have announced the culling of 4.2 million chickens at a large egg farm in Sioux County due to the detection of highly pathogenic bird flu. This comes amid a years-long outbreak affecting millions of birds, including dairy cattle. The recent spread to cattle has raised concerns. Despite assurances from health officials about low public risk, two dairy farm workers have been diagnosed with the virus. The USDA emphasizes the safety of beef from infected cattle. While human cases remain rare, workers in contact with infected animals are at higher risk.