USDA Confirms Highly Pathogenic H7N3 Avian Influenza in a Commercial Flock in Chesterfield County, South Carolina The United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APHIS) has confirmed the presence of highly pathogenic H7N3 avian influenza (HPAI) in a commercial turkey flock in Chesterfield County, South Carolina. This is the first read more USDA Confirms Highly Pathogenic H7N3 Avian Influenza in a Commercial Flock in Chesterfield County, South Carolina