Infectious Diseases 2020

Infectious Diseases 2020

HPAI in a turkey flock in South Carolina

10 April, 2020

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 (34,160 birds). This is the first confirmed case of HPAI in commercial poultry in the United States since 2017. High mortality (1,583 of 34,160, 4.86%) was reported in the flock, along with respiratory signs and snicking.
The affected premises has an epidemiological link to another commercial poultry premises in South Carolina which previously reported LPAI H7N3 in mid-March, following outbreaks of the same strain in eleven turkey flocks in North Carolina. It is thought that the HPAI H7N3 virus emerged through mutation of the LPAI H7N3 strain found recently in the area. There have been reports of 12 cases of low pathogenic avian influenza in the United States in 2020. Eleven of those were in North Carolina while one was in South Carolina.
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. State officials quarantined the affected premises, and birds on the property were depopulated to prevent the spread of the disease.