The H5N2 avian influenza virus has again widened its footprint, invading a large chicken farm in Iowa—the second outbreak in that state—and affecting two more turkey farms in Minnesota, the US Department of Agriculture (USDA) reported today.
In addition, a highly pathogenic H5 virus has hit a chicken farm in Ontario near where H5N2 struck a turkey farm earlier this month, Canadian authorities reported over the weekend. They have not yet specified the virus subtype, but H5N2 seems likely.
Iowa, Minnesota outbreaks
In Iowa, the virus invaded a commercial farm with 5.3 million chickens in the far northwestern county of Osceola, the Iowa Department of Agriculture (IDA) reported. That figure makes the farm the largest one affected by H5N2 so far.
Osceola borders Nobles County, Minnesota, which had a turkey farm outbreak earlier this month, and lies northwest of Buena Vista County, where a farm with 27,000 turkeys was reported hit by the virus on Apr 14, in Iowa's first H5N2 outbreak.
Increased deaths in the Osceola County flock prompted authorities to send samples to the South Dakota State University Veterinary Diagnostic Laboratory for preliminary testing, the IDA said. The USDA National Veterinary Services Laboratories in Ames, Iowa, confirmed the findings.
In Minnesota, a farm with 23,000 turkeys in Kandiyohi County—the state's top turkey-growing county—was hit by the virus, the Minnesota Board of Animal Health (MBAH) reported today. In addition, authorities decided to euthanize all 9,000 turkeys on another farm because of their "exposure" to those on the infected farm, the agency said on its online list of outbreaks.
MBAH spokeswoman Bethany Hahn said the smaller flock was destroyed because of its relationship to the larger one, but said she had no further details on the connection. The two farms are the county's sixth and seventh to be victimized by H5N2.
With the two latest additions, the number of affected farms in Minnesota has increased to 28, in 14 counties, with more than 1.7 million birds lost. Minnesota is the nation's leading turkey-producing state, growing about 46 million birds annually.
North of the border, the Canadian Food Inspection Agency (CFIA) on Apr 18 reported an H5 avian flu outbreak on a broiler breeder chicken farm in southern Ontario's Oxford County, the same area where an H5N2 outbreak on a turkey farm was reported on Apr 6.
The CFIA did not list the number of birds on the farm, but an Apr 19 CTV News report said 27,000 chickens would be euthanized to stop the virus. The story said the CFIA knew of no connections between the two farms but suspected that migratory waterfowl spread the virus.
The CFIA said sudden deaths in the flock over several days led to testing for avian flu, with initial tests conducted at the University of Guelph on Apr 7. Further testing by the CFIA is under way to confirm the virus's pathogenicity and precise subtype, the agency said.
In other developments, Wisconsin Gov. Scott Walker has authorized the Wisconsin National Guard to help respond to H5N2 outbreaks in his state, in response to a request from the state veterinarian, Walker's office announced today.
Walker's order allows the Guard to help contain the outbreak and assist with site clean-up, the statement said. The state veterinarian requested up to 14 Guard personnel be made available on a rotating schedule for immediate assistance. Officials said the help is needed "because federal resources are thin, due to avian influenza virus outbreaks in other states, particularly in the Midwest."
Wisconsin has had three H5N2 outbreaks, involving a turkey farm in Barron County, a backyard flock of 40 birds in Juneau County, and a chicken farm in Jefferson County.
H5N1 spreads in Burkina Faso
In overseas developments, Burkina Faso's animal health ministry today reported seven more H5N1 avian flu outbreaks, affecting farms and backyard poultry in various parts of the country. The new outbreaks come in the wake of four other H5N1 detections reported on Apr 1, which were the country's first since 2006.
The new outbreaks struck birds in four different provinces: Kadiogo (3), Houet (2), Poni, and Boulkiemde. The provinces are in the western and central parts of Burkina Faso. Two of the four outbreaks reported earlier this month were also in Kadiogo.
Four of the outbreaks hit poultry farms that housed chickens, while three involved backyard flocks that included chickens, Guinea fowl, pigeons, and turkeys.
All told, the virus killed 11,308 of 49,718 susceptible birds, and 4,122 have so far been culled to control its spread.
The source of the virus so far isn't known. Other control steps include disinfecting the premises, limiting poultry movement, and strengthening epidemiologic surveillance.
News writer Lisa Schnirring contributed to this article.
Apr 20 Iowa Department of Agriculture statement
MBAH list of Minnesota outbreaks
USDA's national list of recent avian flu outbreaks
Apr 18 CFIA statement
Apr 19 CTV News story
Apr 20 Wisconsin statement on National Guard role
Apr 20 OIE report on Burkina Faso outbreaks