The Sconi

The Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) has confirmed a case of highly pathogenic avian influenza (HPAI H5N1) in a commercial poultry flock located in Jefferson County. The agency is working with the U.S. Department of Agriculture (USDA) animal health officials to respond to the incident.

Following the confirmation, DATCP has quarantined the affected premises to prevent movement of poultry and related products from the site. As part of containment efforts, all birds on the property will be depopulated. Officials have stated that none of these birds will enter the food supply.

According to DATCP, "The H5N1 HPAI virus has continued to circulate in both wild and domestic birds in North America since December 2021." The agency notes that H5N1 is highly contagious among domestic poultry and can often be fatal. It is caused by influenza type A viruses, with severity depending on both strain and species affected. Transmission can occur through direct contact with infected birds, interaction with wild birds or their droppings, contaminated equipment, or clothing worn by individuals handling animals.

DATCP continues to advise livestock owners across Wisconsin to take steps to protect their flocks and herds from this disease. Recommended precautions include handwashing, disinfecting equipment after use, restricting access to animals, and isolating new animals for at least 30 days before introducing them into existing groups. Poultry owners are also encouraged to keep their birds indoors when possible.

In cases where HPAI H5N1 is diagnosed within a Wisconsin poultry flock, an area within a 10-kilometer radius around the infected premises is designated as a control zone. Movement restrictions are put in place for any premises housing poultry within this area. DATCP encourages producers to check if their operations fall within an active control or surveillance zone using available online resources.

The Wisconsin Department of Health Services (DHS) and Jefferson County Public Health are monitoring farm workers who may have been exposed for symptoms associated with HPAI infection. At present, officials report that "the risk to the general public in Wisconsin remains low." Information about prevention measures for farmworkers or others who may come into close contact with potentially infected animals is available through state health channels.

DATCP also reminds livestock owners throughout Wisconsin about the legal requirement to register locations where animals are kept. This registration assists animal health officials in communicating effectively during outbreaks such as this one.

Anyone noticing increased mortality or signs of illness among domestic birds or other livestock should contact DATCP according to posted instructions on its website. Additional updates regarding how avian influenza is affecting domestic bird populations in Wisconsin—as well as guidance on protecting flocks—can be found on DATCP's dedicated HPAI in Poultry webpage.

Since December 2021, H5N1 has not only circulated among wild and domestic bird populations but has also impacted some mammalian species across North America. However, there have been no reported cases of H5N1 infection detected among dairy herds within Wisconsin so far. DATCP states it continues collaboration with USDA on ongoing testing initiatives for H5N1 while promoting biosecurity practices and providing support resources for agricultural producers statewide.

For broader information about how the virus affects dairy cattle nationally—and additional resources aimed at safeguarding Wisconsin’s dairy industry—producers can visit DATCP's H5N1 in Dairy Cattle webpage.