Nearly 1 million chickens in Minnesota have contracted the bird flu in one flock there, the U.S. Department of Agriculture reported this week and under federal guidelines, will be killed in an effort to prevent the disease from spreading.

The highly-contagious avian influenza virus was mainly found at a farm in Wright County, located in the east central part of the state, just northwest of Minneapolis, according to statistics posted on the USDA website and a report from the Associated Press.

Whenever the bird flu is detected in a flock, it must be destroyed to prevent the disease from spreading, according to USDA fact sheet.

As of Tuesday, 1,302,450 birds in the state were infected with the virus that has killed hundreds of thousands of domestic and wild birds across the world, according to information from the USDA and the state's Department of Natural Resources. The virus can cause mild to severe illness in people.

According to the USDA, the virus was also found in flocks in two of Minnesota's four neighboring states of Iowa (162,550 birds) and South Dakota (300,800 birds).

The federal agency also said 26,800 turkeys are slated to be slaughtered at a McPherson County farm in South Dakota, the AP reported, and just under 17,000 birds are set to be killed on two farms in Iowa’s Clay County.

A USDA spokesperson could not immediately be reached for comment Wednesday.

What is the bird flu? 

The bird flu, is disease caused by a family of flu viruses primarily transmitted between birds.

Avian influenza viruses, according to the CDC and USDA, are classified into two groups: Low Pathogenic Avian Influenza (LPAI) (often seen in wild birds) and Highly Pathogenic Avian Influenza (HPAI) (found mostly in domestic poultry). According to the Centers for Disease Control, LPAI viruses cause mild or no disease and HPAI cause severe disease and high mortality rates in infected birds.

The bird flu has cost the government roughly $660 million and in recent times raised the price of eggs and poultry. At least 58 million birds have been slaughtered this year to limit the spread of the virus.

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What are signs of bird flu?

Indications a bird may be infected with avian influenza include:

• Loss of appetite, lethargy
• Sudden death without prior symptoms
• Eyelid swelling
• Twisting of the head and neck
• Purple discoloration to body parts including waddle and legs

• Stumbling and falling
• Diarrhea
• Difficulty breathing
• Nasal discharge

Bird flu symptoms in humans

Bird flu infections in humans are rare according to the CDC.

The first case of avian influenza in a person in the United States was reported in Colorado in April 2022.

As of Wednesday, according to CDC stats, only four human infections with LPAI viruses had been identified in the United States - and all four people suffered mild-to-moderate illness.

Human infection with the bird flu can happen during close contact with infected birds or when people touch sick birds or their saliva, mucus and feces, the CDC said. People contract the virus when it gets into a their eyes, nose or mouth, or when it is inhaled.

Those who contract the virus often experience mild illnesses including an eye infection and upper respiratory symptoms or no symptoms at all, while others can develop a severe sometimes fatal disease like pneumonia.

Natalie Neysa Alund is a senior reporter for USA TODAY. Reach her at [email protected] and follow her on X @nataliealund.