On April 9, USDA Animal and Plant Health Inspection Service (APHIS) confirmed the presence of highly pathogenic H7N3 avian influenza (HPAI) in a commercial turkey flock in Chesterfield County, SC. This is 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 has been found in poultry in that area of North and South Carolina recently.

Samples from the affected flock, which experienced increased mortality, were tested at the Clemson Veterinary Diagnostic Center, part of the National Animal Laboratory Network, and confirmed at the APHIS National Veterinary Services Laboratories (NVSL) in Ames, Iowa. Virus isolation is ongoing.

APHIS is working closely with the SC State Veterinarian’s Office, part of Clemson University, on joint incident response. State officials quarantined the affected premises, and birds on the property were depopulated to prevent the spread of the disease. Birds from the flock will not enter the food system.

As part of existing avian influenza response plans, federal and state partners are working jointly on additional surveillance and testing in the nearby area. The United States has the strongest A.I. surveillance program in the world, and USDA is working with its partners to actively look for the disease in commercial poultry operations, live bird markets and in migratory wild bird populations.