St. Paul, MN (KROC-AM News) -The number of commercial poultry flocks with confirmed outbreaks of a virulent bird flu in Minnesota grew by about 40-percent on Wednesday.

The U.S. Agriculture Department announced that tests confirmed new outbreaks in 13 flocks involving about 430,000 turkeys in Kandiyohi, Meeker, Otter Tail and Stearns Counties. Each of those counties had previously seen at least one other outbreak.

The total number of outbreaks has risen to 44 and a number of turkeys killed by the H5N2 virus, or destroyed to slow its spread, is now over 2.5 million in Minnesota.

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Federal officials have indicated preliminary work is underway on the development of a possible bird flu vaccine for humans as the virus continues to devastate turkey and chicken farming operations in the Midwest.

They stress that the risk from the virus to humans remains low and note there have been no human infections, but development work on a potential vaccine is standard operating procedure with all emerging diseases.

(Associated Press contributed to portions of this story)

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