Depleted S. Carolina Flock Yielded HPAI

A 12-week tom grow-out flock in Chesterfield County SC. yielded an H7N3 avian influenza virus with basic amino acid substitution at the HA cleavage site indicating high pathogenicity.

The flock, spread among a five-house farm, demonstrated mild respiratory signs and ascending low-grade mortality before a presumptive diagnosis of H7 influenza was made, leading to depletion using carbon dioxide foam and disposal by in-house composting

A series of eleven low-pathogenicity H7N3 cases have been diagnosed since mid-March in Anson and Union Counties, NC and an additional case in adjacent Chesterfield County, SC. All asymptomatic flocks were promptly identified by surveillance and a total of 350,000 turkeys have been depleted.