A commercial chicken-breeding operation has tested positive for low-pathogenic avian influenza in Giles County, Tennessee. The company that manages the operation is different from the one associated with the recent detection of highly-pathogenic avian influenza in Lincoln County, Tennessee. Officials do not believe poultry from one premises sickened the other.
Routine screening March 6 at the Giles County premises indicated presence of avian influenza. State and federal laboratories confirmed the existence of H7N9 low-pathogenic avian influenza in tested samples.
The affected flock was depopulated and has been buried. The operation is under quarantine. Domesticated poultry within a 6.2-mile radius of the site also are under quarantine and are being tested and monitored for illness. To date all additional samples have tested negative for avian influenza. No other flocks within the area have shown signs of illness, according to the Tennessee Department of Agriculture.
The main difference between low-pathogenic avian influenza and highly-pathogenic avian influenza is mortality rate in domesticated poultry. A slight change to the viral structure can make a virus deadly for birds. Avian influenza virus strains often occur naturally in wild migratory birds without causing illness in those birds, according to the Tennessee Department of Agriculture.
The Giles County incident is similar to the Lincoln County incident in that both the low-pathogenic and highly-pathogenic viruses are an H7N9 strain of avian influenza. The U.S. Department of Agriculture’s National Veterinary Services Laboratories confirms the H7N9 virus that affected the Lincoln County premises is of North American wild-bird lineage. It is not the same as the China H7N9 virus affecting Asia, and is genetically distinct.
The Lincoln County operation remains under quarantine. All additional poultry samples from the area surrounding that site have tested negative for avian influenza and no other flocks within the area have shown signs of illness. Testing and monitoring continues.
Visit www.tn.gov/agriculture/news/49066 for more information.