MINNEAPOLIS — After routine testing discovered a strain of the avian flu virus in a commercial turkey flock in central Minnesota, the flock was quarantined, according to The Associated Press. The avian flu strain found at the Meeker County farm, however, is different from the more lethal strain that has caused problems in birds and humans primarily in Asia, stressed Dale Lauer, Minnesota Board of Animal Health assistant director.

Mr. Lauer, who is a veterinarian, said the strain of virus found at the farm does not pose a threat to the general public, but could cause mild symptoms in poultry workers. The quarantined flock was showing no signs of illness, he said, but if left unchecked the virus could morph into a form that could be lethal to the state's commercial poultry flocks. Minnesota is the nation's top turkey-producing state.

The flock and other flocks within three miles of the unidentified farm will stay under quarantine for six weeks while they are repeatedly tested for the virus, Mr. Lauer said. If the animals recover, they could go back into the food supply. The board's testing frequently finds blood evidence that domestic turkey flocks have been exposed to strains of the avian flu, he said. The Meeker County flock was somewhat different in that testing found live virus. "It simply means our testing methods are getting better," he said.

Domestic turkey operations can get the virus from wild turkeys and migrating waterfowl, Mr. Lauer said. He called the Meeker County incident another reminder for poultry producers to secure their flocks.

The Minnesota Health Department is monitoring about 20 poultry workers at the turkey farm because the strain of virus found there, H7N9, has been known to cause mild eye infections and mild respiratory problems in people who work with infected turkeys.