By Ralph Ellis CNN

(CNN) -- A strain of bird flu has been found in a commercial chicken farm in Tennessee, the US Department of Agriculture and state government agencies said Sunday.

The H7 strain of Highly Pathogenic Avian Influenza, or HPAI, was found in a flock of 73,500 chickens in Lincoln County, in the central part of the state on the border with Alabama, the USDA said.

The facility alerted authorities Friday that a large number of chickens were dying, the USDA said.

Tyson Foods said the farm is owned by an individual who contracts with the company.

"We're responding aggressively, and are working with state and federal officials to contain the virus by euthanizing chickens located on the farm," Tyson said. "All flocks located within a 6-mile radius of the farm will be tested and will not be transported unless they test negative for the virus."

"Birds on the property will be depopulated to prevent the spread of the disease. Birds from the flock will not enter the food system," the USDA's Animal and Plant Health Inspection Service said.

This is the first known case of HPAI in a commercial poultry facility in the United States this year, the USDA said. This is also the first HPAI case in Tennessee, the state said.

In January 2016, a commercial turkey farm in Dubois County, Indiana, tested positive for the H7N8 strain of avian influenza.

"These virus strains can travel in wild birds without them appearing sick," the USDA said of the latest outbreak. "People should avoid contact with sick/dead poultry or wildlife. If contact occurs, wash your hands with soap and water and change clothing before having any contact with healthy domestic poultry and birds."

This kind of bird flu doesn't pose a risk to the food supply, the Tennessee statement said, and the risk of human infection during bird flu outbreaks is low.

Bird flu is a bigger problem overseas than in the United States. A total of 460 people in China have had confirmed infections of avian influenza since October, according to the World Health Organization.

In 2014, a man in Alberta, Canada, died from bird flu. In 2015, millions of birds were euthanized after an outbreak in Iowa.

Bird flu usually just affects birds. Most cases of human bird flu infections are due to contact with infected poultry or surfaces that are contaminated with infected bird excretions: saliva, nasal secretions and feces.

Symptoms of avian flu include fever, cough, sore throat and sometimes severe respiratory diseases and pneumonia.

There are many strains of avian flu, 16 H subtypes and 9 N subtypes. Only those labeled H5, H7 and H10 have caused deaths in humans.

CNN's Janet DiGiacomo contributed to this report.

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