By Jon Hurdle
PHILADELPHIA (Reuters) - A flock of 12,000 chickens in Delaware was destroyed on Saturday in a bid to prevent the spread of avian flu, and state agriculture officials hastened to say the virus differs from the one that has killed people in Asia.
The chickens were slaughtered on a farm in southern Kent County, Delaware, at 11:30 a.m. after two birds tested positive for the virulent H7 virus on Friday, Delaware agriculture secretary Michael Scuse said.
The virus is different from the H5N1 virus in Asia, Scuse said. That strain has forced the slaughter of millions of birds there and killed 18 people in Thailand and Vietnam who had come into direct contact with them.
"The virus that is in Asia is a mutation of H5," Scuse said. He said the H7 strain found in Delaware is fatal to poultry but does not transmit to humans.
Scuse said he was "fairly confident" the virus had not spread. As a safeguard, however, other flocks within a two-mile radius of the infected farm would be tested, and the outcome of that process would probably be known by Tuesday, he said.
If the virus is found in any of the other flocks, the testing area would be extended to five miles, he said.
The slain flock's carcasses will be composted at the farm, which has been quarantined, he said.
South Korea, which is battling a deadly outbreak of the virus, reacted swiftly to reports of the discovery in Delaware, immediately halting imports of U.S. poultry.
Poultry is a multibillion-dollar industry in the Delmarva Peninsula where the infected farm is located, and is the mainstay of the local economy. The Delmarva region, which lies between the Chesapeake Bay and the Atlantic Ocean, consists of parts of Delaware, Maryland and Virginia.
The farmer did not supply chickens to Purdue or any other commercial poultry company, said Anne Fitzgerald, a spokeswoman for the Delaware Agriculture Department.
Officials declined to release the precise location of the farm or its owner, saying that quarantine regulations required a minimum of traffic in the area.