Thousands of Hens Exposed to Bird Flu in Arkansas

Tyson Foods Inc. has begun killing and burying the carcasses of 15,000 hens in northwest Arkansas that tested positive for exposure to a strain of the avian flu that is not harmful to humans, state officials said Tuesday.

Jon Fitch, director of the state's Livestock and Poultry Commission, said routine blood tests conducted Friday found the possible exposure. Further tests done by the state and the U.S. Department of Agriculture found the birds did not have active infections, but rather were exposed to a subtype of the disease.

Fitch said the company immediately began disposing of the birds.

"There is absolutely no human health threat," Fitch said. "But we take this very seriously."