breaking news - fatal bird flu found on texas farm

WASHINGTON (CNN) -- An entire flock of chickens on a farm in the United States has been destroyed after being diagnosed with a serious strain of bird flu.

Weekend tests showed the Texas flock had the H5N2 strain of the virus, classified by the U.S. Agriculture Department as "highly pathogenic" to poultry.

It is the first outbreak in the U.S. of a severe form of the disease in 20 years, when more than 17 million birds were killed at a cost of nearly $65 million, Reuters reported.

Officials are not ruling out a human risk, but the U.S. Center for Disease Control says although the strain is fatal in animals, it does not pose a dangerous threat.

"Past experience with H5N2 viruses has indicated there is a low threat to public health," Dr. Nancy Cox of the Centers for Disease Control and Prevention told reporters.

"Nevertheless, as we move forward with this situation, we must keep an open mind and really monitor the situation as we go."

Ron DeHaven, the U.S. Agriculture Department's chief veterinarian, told reporters on Monday that there was "no epidemiological link" between the Texas infection and the Asian outbreak.

More than 80 million chickens and other fowl have been destroyed by the H5N1 strain of the disease that has killed at least 22 people in Asia since December.

A milder strain was found earlier this month in the U.S. states of Pennsylvania, Delaware and New Jersey.

Health officials are monitoring workers on the Texas farm in Gonzales County, and tests showed some of the farm's flock did make it to two live markets in Houston.

Birds were being tested on farms within a 10-mile (16-kilometer) radius, Mark Michalke, a Texas Animal Health Commission veterinarian was quoted by The Associated Press as saying.

Shares in poultry companies, including the nation's largest poultry producer, Tyson Foods Inc., fell in response to the Texas case. Tyson slipped 46 cents to $15.40 per share, Reuters reported.

More than two dozen nations have banned imports of some U.S. poultry since bird flu emerged in U.S. flocks.

"Our government is presenting the facts of the situation to other countries, and we hope that the trade repercussions will be limited," said Richard Lobb, a spokesman for the National Chicken Council.

Texas produced 2.88 billion pounds (1.3 billion kg) of poultry in 2002, according to industry figures.

Meanwhile, the United Nations has fears that the epidemic in Asia will make life harder for the poor.

Many small-time poultry farms have been devastated, along with huge conglomerates that process chicken.

Bangkok officials also recently confirmed the deaths of two house cats from bird flu, the first domesticated mammals known to have contracted the disease in this outbreak. (WHO allays bird flu fears)