On Apr. 9, 2020, the U.S. Department of Agriculture (USDA) confirmed the presence of highly pathogenic H7N3 avian influenza (HPAI) in a commercial turkey flock in Chesterfield County, South Carolina. This was the first confirmed case of HPAI in commercial poultry in the United States since 2017.

It appears this HPAI strain mutated from a low pathogenic strain that was found in poultry in that area recently. No human cases of this H7N3 avian influenza virus had been detected and there was no immediate public health concern.