An outbreak of low pathogenic H7N3 avian influenza has been confirmed in an 18-week-old commercial turkey flock in Merced County, California, according to a March 17 report from the World Organisation for Animal Health (OIE).

The USDA Animal Plant Health Inspection Service (APHIS) and the California Department of Food and Agriculture (CDFA) are conducting a comprehensive epidemiological investigation of the outbreak, where turkeys were seen coughing and experiencing a slight increase in mortality. Samples were submitted to state and national laboratories, where tests proved positive for H7N3 avian influenza.

An estimated 61,000 turkeys were susceptible, according to the OIE. The farm or any poultry companies it may be affiliated with has not been released.


The infected operation was placed under quarantine following preliminary findings and an epidemiological investigation was initiated. Follow-up surveillance and testing on 10 epidemiologically associated farms proved negative for avian influenza.

The latest confirmed case of marks the third discovery of the avian influenza in commercial flocks in California, however, it is only the first of the H7N3 serotype. Animal health agencies on January 24 confirmed the presence of highly pathogenic H5N8 avian influenza in a Foster Farms turkey flock in Stanislaus County, and another H5N8 outbreak in a commercial broiler and duck flock in Kings County was confirmed in February.