A bird-flu strain that has already led to the deaths of nearly 2 million turkeys nationwide spread to an Iowa turkey farm, authorities said on Tuesday, bringing to six the number of states hit with the outbreak that was also confirmed at eight more farms in Minnesota.
The announcements on Tuesday came a day after confirmation of the first case of the virus in Wisconsin, the first case of a U.S. commercial chicken farm where the strain was detected, according to the U.S. Department of Agriculture.
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Scientists believe domestic poultry are getting the highly-contagious H5N2 virus from wild migratory waterfowl but they are puzzled by the accelerating spread despite reinforced biosecurity measures at poultry production and processing facilities. The outbreak has prompted some 40 countries to impose import restrictions on U.S. poultry
The Iowa farm is in Buena Vista County housing some 27,000 turkeys, said Iowa Department of Agriculture spokesman Dustin Vande Hoef. The disease was suspected when an abnormally high number of turkeys began dying. The farm is under quarantine and the turkeys will be destroyed.
The confirmation at eight additional infected turkey farms in the nation's biggest producing state of Minnesota brings the state's total to 22 farms and nearly 1.5 million turkeys lost to the disease. Minnesota raises around 46 million turkeys a year. State Veterinarian Bill Hartmann said he expects more farms to be hit before the threat recedes.
Animal health officials have long said the virus is dangerous to all commercial poultry. Iowa has 130 turkey farms raising 11 million turkeys a year. The state also is the nation's leading egg producer with more than 59 million egg layers but no chicken flocks in Iowa have been infected.
The U.S. Department of Agriculture posted a notice on Monday that Canadian officials added Iowa to the list of states prohibited from exporting raw poultry products.
"I think it is important to note there's no human health consequence to any of the previously found avian influenza outbreaks in the upper Midwest nor do we expect that here," said Randy Olson, Iowa Poultry Association's executive director.
Iowa Turkey Federation executive Gretta Irwin said food is safe. No birds from infected farms make it into the food supply since they're destroyed and composted on the farm. Poultry is tested for influenza before it leaves the farm for slaughter, she said.
Commercial turkey flocks in Arkansas, Missouri, North Dakota and South Dakota have confirmed cases of the H5N2 strain in turkeys in addition to Iowa and Minnesota. Counting turkeys killed by the disease and those destroyed or soon to be killed to stop its spread, about 1.8 million birds have been lost in the Midwest or approaching 1 percent of the 235 million turkeys produced in the U.S. last year.
The virus was confirmed in a commercial chicken flock in Wisconsin on Monday affecting 200,000 birds. Cases also have been found in commercial poultry flocks in Ontario and British Columbia in Canada.
Scientists haven't found hard evidence yet of the link to wild fowl. Minnesota Department of Natural Resources Commissioner Tom Landwehr said Tuesday that tests on fecal samples of wild birds his researchers have collected near infected farms have all come back negative so far.
The virus also has been found in backyard birds in several states including Idaho, Kansas, Montana, Oregon and Washington.
A different strain of the virus, H5N8 has been identified in chickens and turkeys in California.
Bird flu viruses also have been confirmed in wild birds including falcons in Idaho, Missouri, Montana, and Washington.
Associated Press writer Steve Karnowski contributed to this report from Minneapolis.
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