On Dec. 18, the Wisconsin Department of Health Services announced that it detected the first presumptive positive human case of highly pathogenic avian influenza A (H5N1), also known as bird flu, in Barron County in the northwestern part of the state. The human case follows an infected flock of commercial poultry identified in Barron County last week.

The person identified is a female farmworker who had exposure to the infected flock last week. The case was identified through testing at the Wisconsin State Lab of Hygiene and is pending confirmation at the Centers for Disease Control and Prevention.

DHS, in coordination with Barron County Health and Human Services, is monitoring 19 farmworkers from that commercial poultry farm who may have been exposed to the virus and has provided them with information to protect their health. The risk to the general public in Wisconsin remains low, according to DHS. People who work with infected animals, or have recreational exposure to them, are at higher risk.

The H5N1 HPAI virus has continued to circulate in both wild and domestic birds in North America since December 2021. H5N1 HPAI viruses are highly contagious and often fatal to domestic poultry. Caused by influenza A viruses, the disease can cause illnesses ranging from very mild to severe depending on the strain and species affected. The disease can spread from infected birds to people by contact with infected birds, commingling with wild birds or their droppings, equipment, or clothing worn by anyone working with the animals.

The virus does not spread easily from animals to people. People who have gotten sick with bird flu have been in direct contact with infected animals.

Symptoms of bird flu in people include:

Anyone who develops symptoms of flu or an eye infection and has been in contact with animals who may have been infected should stay home (not go to work, school, shopping or use public transportation) and call their doctor’s office or clinic before visiting so they can take precautions to ensure other patients are not exposed to the virus. Treatment for bird flu may include hospitalization, supportive care and the use of antivirals.

HPAI confirmed in Kenosha County

Also on Dec. 18, the Wisconsin Department of Agriculture, Trade and Consumer Protection identified a case of H5N1 HPAI in a poultry flock in Kenosha County. According to DATCP, there are 88 chickens and five ducks in the flock. DATCP and USDA animal health officials are working together in a joint incident response.

The affected premises will not move poultry or poultry products, and birds on the property will be depopulated to prevent the spread of the disease. The flock is located near the Wisconsin-Illinois border. Birds from the flock will not enter the food system.

DATCP continues to urge all livestock owners to implement strong biosecurity measures to protect their flocks and herds from the disease. This includes washing hands, disinfecting equipment, restricting access to animals, and separating new additions to the flock or herd for at least 30 days.

When HPAI H5N1 is diagnosed in a Wisconsin poultry flock, a control area is established within a 10-kilometer area around the infected premises, restricting movement on or off any premises with poultry.

Boost biosecurity

While no dairy herds have tested positive for bird flu in Wisconsin, during a Zoom press conference on the afternoon of Dec. 18, Wisconsin State Veterinarian Darlene Konkle said, “Avian influenza is a very fast-moving disease. We have been encouraging dairy farmers to up their biosecurity.”

Konkle noted that this is the time of year when Wisconsin sees more cases of bird flu in poultry.

“This is when there are more migratory birds coming through the state,” Konkle said.