Officials in Alabama are closely monitoring poultry operations here after thousands of chickens in Lincoln County, Tennessee, were destroyed after avian influenza was found in a commercial breeder flock.

Most of Lincoln County borders Madison County, Alabama, though the county’s western edge borders the eastern-most part of Limestone County. Tennessee’s Department of Agriculture is not identifying the farm where the chickens were destroyed.

Thirty other farms within a six-mile radius of the affected farm have been quarantined. No other flocks in the control zone have experienced an increase in mortality, and the first round of testing has been negative for avian influenza.

The Tennessee breeder where the virus was found supplies Tyson Foods Inc. The company said it doesn’t expect its chicken business to be disrupted.

“We’re responding aggressively and working with state and federal officials to contain the virus,” Tyson said in a company release.

Only one commercial chicken farm in Alabama was within the six-mile radius, the state said, and all the birds there tested negative for the flu. That Alabama farm was also used by Tyson, according to the state. Alabama said it also began testing chickens in people’s backyards within in the affected area, and all the tests have come back negative so far.

Commissioner John McMillan assured Tennessee Commissioner of Agriculture Jai Templeton that Alabama officials would continue to work closely with the Tennessee Department of Agriculture.

“I want to assure all Alabamians that our department will continue our surveillance for avian influenza and approach this incident with an abundance of caution,” McMillan said. “Every flock of chickens in Alabama is tested for avian influenza before being processed for human consumption.”

About avian influenza

“Bird flu” is a catch-all phrase for a variety of influenza viruses that spread among poultry. They can be very contagious and deadly among birds, but rarely spread to humans. The technical name for the influenza found in Tennessee is highly pathogenic H7 avian influenza (HPAI).

Flu can spread from birds to humans through the air, or when people touch a bird or an infected surface and then touch their eyes, nose or mouth. The risk of human infection with avian influenza during poultry outbreaks is very low, however.

No transmission to humans was reported during the outbreak that affected commercial poultry farms in the Midwestern United States in 2015. Also, this is not the same strain identified in that outbreak.

Frazier and Tennessee State Veterinarian Dr. Charlie Hatcher encourages commercial poultry producers and backyard flock owners to observe their birds closely and continue to practice strict biosecurity measures. These include:

• Isolating birds from other animals;

• Wearing clothing designated for use only at the poultry house;

• Minimizing access to people and unsanitized equipment;

• Keeping the area around the poultry buildings clean and uninviting to wild birds and animals;

• Sanitizing the facility between flocks;

• Cleaning equipment entering and leaving the farm;

• Having an all in, all out policy regarding the placement and removal of the poultry;

• Properly disposing of bedding material and mortalities; and

• Avoiding contact with migratory waterfowl.

The Alabama Department of Agriculture and Industries Poultry Division is available to answer any questions concerning movement of poultry and should be notified at 334-240-6584 if birds show unusual signs of disease (flu-like symptoms) or flocks experience unexplained mortalities.

The Alabama Cooperative Extension System has created a website to assist backyard flock owners with maintaining healthy birds and to provide answers for avian influenza control. It can be found at www.AlabamaAvianInfluenza.com.

— The Associated Press contributed to this report.