DATCP: Bird flu cases at Jefferson Co. poultry facility, backyard flock in Rock Co. likely came from wild birds

MADISON, Wis. — Agriculture officials say cases of highly pathogenic avian influenza at a commercial poultry facility in Jefferson County and a backyard flock in Rock County likely came from contact with wild birds.

Speaking to reporters Wednesday afternoon, officials from the Wisconsin Department of Agriculture, Trade and Consumer Protection (DATCP) said they looked at bird movements and used information from the flocks’ owners to identify a source for the bird flu cases. Based on that data and epidemiology, DATCP state veterinarian Dr. Darlene Konkle said both cases appear to be independent and came from wild birds coming in contact with the flocks.

“In each case, we think these two are independent and we think each of them is (an) introduction from a wild bird contact of some sort,” she said.

Commercial poultry farms have biosecurity measures in place to try to prevent exposure to viruses, but those efforts aren’t infallible. Contact with wild birds is one of multiple ways it can spread.

“There still is enough movement of people (and) equipment on and off of these premises that there’s always a chance of basically tracking in the virus with some of that movement,” Konkle said.

With migratory birds moving through the area this time of year, agriculture officials are on “high alert” for the virus, she said.

DATCP first confirmed the positive bird flu case at the Jefferson County facility — which officials confirmed on Wednesday was the Cold Spring Egg Farm — on March 14. The birds at the facility — more than 2.7 million — were killed to avoid spreading the virus; depopulation efforts wrapped up late last month.

The birds are being composted on a nearby site owned by the farm where the virus was discovered. In response to a question about potential impacts on groundwater, Natasha Gwidt, a field operations director from the Wisconsin Department of Natural Resources, said the site meets requirements about distances from wells and bodies of water.

The birds’ remains, she explained, will be mixed with sawdust and other material and encapsulated in more than a foot of a carbon material she described as woody vegetation. As the inside of the pile warms, it will harden the outer layer of material, which will form a protective barrier keeping water out.

“We won’t get — and we don’t want to get — any sort of runoff or water or any leeching coming out of those compost piles; that woody material should absorb that so there’s no runoff,” she said. “Any water that would come in contact with the birds would be fixed on-site.”

Regardless, people with private wells should test them regularly, she added.

RELATED: Avian influenza found in wild birds in Wisconsin, DNR says

On March 31, the DNR confirmed the EA H5 avian influenza had been found in wild birds after samples were taken from half a dozen birds in various parts of the state, including Dane, Columbia and Grant counties.

Days later, DATCP announced the positive case at the backyard flock in Rock County. The nearly two dozen birds in that flock have also since been killed to keep the virus from spreading.

HPAI does not pose an immediate threat to humans, according to health officials. Cooking poultry and eggs to an internal temperature of 165 degrees kills the virus.