MADISON, Wis. (AP) — Wisconsin agriculture officials have lifted all quarantines imposed on poultry farms because of the bird flu.

The Department of Agriculture, Trade and Consumer Protection said Tuesday it has released the final six poultry producers from quarantine, including four farms in Barron County and two in Jefferson County.

READ MORE: Alec Baldwin Fired Prop Gun That Killed Cinematographer, Injured Director On Movie Set (CBS News)

More than 49 million birds died or were euthanized this spring in 15 states as the virus spread from the Pacific Northwest into Midwest farms. Wisconsin producers lost nearly 2 million chickens and turkeys as a result of the virus.

READ MORE: 3 People Shot In Separate Minneapolis Shootings Thursday Night

State veterinarian Paul McGraw says he’s concerned the disease may reappear in the fall months when temperatures begin to drop and wild birds begin to migrate south for the winter.

MORE NEWS: Data Show COVID Cases In Minnesota Schools Have Declined, But Experts Still Watching For Long-Term Trends

(© Copyright 2015 The Associated Press. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.)