Bird Flu Found in Texas Turns Out to be 'Highly Pathogenic' Strain

Feb. 23, 2004
By NELSON ANTOSH
Copyright 2004 Houston Chronicle

The U.S. Agriculture Department said today that additional testing has found that sick chickens found on a Texas farm last week were infected with a "highly pathogenic" strain of bird flu rather than the milder form first suspected.

Although humans can catch it and the Centers for Disease Control is swinging into action, the far bigger threat is to farms, where such a virulent strain can wipe out an entire flock.

About 6,600 chickens from the farm, located about 50 miles east of San Antonio, were destroyed over the weekend, and the USDA inspected two Houston live-poultry markets where that farm's chickens are normally sold. Inspectors destroyed about 20 ducks found at one of those markets but found no live poultry at the other market.

Ron DeHaven, the USDA's chief veterinarian, said there is "no connection whatsoever" between the the H5N2 strain of bird flu found at the Gonzalez County farm and the strain of avian influenza causing panic in some Asian countries. Health officials are worried about the Asian strain because it has jumped from birds to people and has killed at least 22 people so far.

Nonetheless, the Centers for Disease Control said it would closely monitor any threat to human health from the bird flu found in in Texas.

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

When the virus last popped up in in 1983-84 in Pennsylvania and Virginia, no humans caught it. As a precaution, however, poultry workers are being told to monitor their health.

"We will be mounting a full-court press to monitor threats to human health," said Cox. 

A command post was set up this morning in the Gonzales area, said officials of the Animal and Plant Health Inspection Service. The Texas farm was already quarantined and farms within 10 miles of it are being tested for the disease.

Last Friday, USDA officials had said they thought the virus was a mild version of bird flu that could kill about 10 percent of a flock.

Genetic sequencing done over the weekend, however, revealed it was much more potent, capable of killing 20 to 30 percent of a flock or in some cases even decimating an entire flock. Some of the chickens at the Gonzalez County farm died of the disease, and farmers are worried about the financial impact.

Even before anyone knew that the flu was stronger than first thought, Russia, the biggest foreign buyer of U.S. chickens, moved immediately to temporarily ban the purchase of Texas chickens, and there was fear Japan might follow suit.

The next step is injecting susceptible chickens with the Gonzales virus to further confirm that it is highly pathogenic. It will take about 10 days to get the results.

Reuters News Service contributed to this report.
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