Idaho bird farm quarantined
Friday, September 5, 2008 12:24 PM PDT
BOISE (AP) — A southwestern Idaho bird farm has been quarantined after two birds there were found to have a bird flu virus, but Idaho Department of Agriculture officials say it is not the same virus that has spread through birds in Asia, Europe and Africa.
About 300 birds were shipped from the farm to a bird dog sporting event at Prado Regional Park in Chino, Calif., just before the virus was detected, and all of those birds were quarantined and euthanized, said Larry Hawkins, a spokesman with the U.S. Department of Agriculture in Sacramento, Calif. The trucks used to transport the birds were disinfected and the suits and other materials used to collect them were incinerated, Hawkins said.
It does not appear as if the virus spread to any animals beyond the two at the farm in the Treasure Valley region of Idaho, said Bill Barton, the state veterinarian with the Idaho Department of Agriculture. The virus is not uncommon among wild birds, Barton said, and poses little or no risk to human health. In domesticated birds, it can cause coughing and respiratory illness, according to the Centers for Disease Control, but rarely causes more serious illness and often goes undetected. The Idaho farm has thousands of pheasants, chukars, ducks and quail, Barton said, but all of the birds are used for sporting events, not human consumption. Finding the virus does cause concern, Barton said, because there is a small risk it could mutate to a more virulent strain.
Identifying and classifying the types of bird flu viruses is complicated and requires sophisticated molecular testing.
‘‘It would be nice if it were simpler,’’ said Walter Boyce, a University of California, Davis professor of veterinary medicine and the co-director of the school’s Center for Rapid Influenza Surveillance and Research. Boyce is an expert in bird flu but is not involved in the investigation or testing of the Idaho game birds.
There are essentially two types of bird flu viruses, Boyce said: H-types and N-types. Viruses classified as an N-type are generally not of concern. But the H-type viruses are more closely monitored, because at least two versions of that type — H5 and H7 — are known to be able to mutate into new viruses.
The deadly, highly pathogenic bird flu virus found in Asia and parts of Europe is H5N1, Boyce said, and is considered a high-pathogen virus, meaning it is more contagious and more easily spread.
The virus found at the Idaho farm was classified as H5N8, said Barton, and is a low-pathogen virus, considered much less dangerous.
It’s fairly rare for a low-pathogen virus to mutate into the more dangerous high-pathogen type, said Boyce, but it can happen, especially in situations where large numbers of birds are kept together in close quarters.
It’s not yet known when the Idaho birds became infected, Barton said. The birds were kept in an outside pen area that was covered with plastic mesh, he said, and they could have been exposed to the virus through droppings from a wild bird flying or roosting overhead.
Other than the California shipment, it was not immediately clear where other birds in the flock had been shipped in recent weeks, Barton said. The farm’s owner, whom Barton declined to identify, was cooperating completely with the investigation.
‘‘They’ve been so helpful, and they’ve done everything right,’’ Barton said. ‘‘They’re excellent producers and proactive, and these things can still happen sometimes.’’
Barton said he didn’t know yet how long the farm will be quarantined, or if the rest of the flock will be euthanized. That will depend on the investigation, which could take some time.
Department officials are examining all bird farms in a roughly two-mile radius of the affected farm, he said, and the farm where the birds were found is being disinfected.
The virus was found in the two infected birds incidentally as testing was being done to check for a common bacteria, Barton said.
