According to the US Department of Agriculture Animal and Plant Health Inspection Service, the state of California confirmed a case of highly pathogenic avian influenza on a commercial meat turkey operation in Stanislaus, California. Some 51,000 turkeys were impacted by the outbreak. 

Small outbreaks have been reported in states across the US, including North Dakota, Oregon, Colorado, Pennsylvania, Utah and Wisconsin. Some have been in small backyard flocks, but several commercial turkey operations have been impacted.

Avian influenza viruses are classified as either “low pathogenic” or “highly pathogenic” based on their genetic features and the severity of the disease they cause in poultry. Most viruses are of low pathogenicity, meaning that they causes no signs or only minor clinical signs of infection in poultry.