Over the weekend, federal and state agriculture officials announced Colorado's first avian flu outbreak, continuing the westward expansion of detections in poultry and lifting the number of affected state to 26.
Meanwhile, earlier-affected states reported more outbreaks, notably Minnesota, where turkey producers have now lost more than 1.3 million birds.
Colorado backyard flock hit
The outbreak in Colorado struck a backyard flock in Pitkin County in the west central part of the state near Aspen. The Colorado Department of Agriculture said a veterinarian from the area reported that 35 of 36 birds in the flock died after having known exposure to sick waterfowl.
One of the birds was sent for testing to the Colorado State University Veterinary Diagnostic Lab, and the positive findings were confirmed at the US Department of Agriculture (USDA) National Veterinary Services Laboratory in Ames, Iowa.
In late March, the USDA Animal and Plant Health Inspection Service (APHIS) reported the first detection in a wild bird from Colorado, and since then, surveillance has turned up the virus 15 times in waterfowl, mainly geese, from four of the state's countries.
Crisis deepens for Minnesota turkey farms
In related developments, APHIS reported five more outbreaks in poultry, including two from Minnesota. The Minnesota Board of Animal Health (MBAH) now reports 28 outbreaks in 14 of the state's 87 counties. Most are in west central Minnesota.
Minnesota is the nation's top turkey producer, and the outbreaks have led to the loss of 1.37 million birds, according to the latest update from the MBAH.
Elsewhere, Montana reported two outbreaks in backyard flocks, one in Judith Basin County and the other in neighboring Cascade County. Both are in the central part of the state. Also, North Carolina reported an outbreak at a commercial broiler farm in Wayne County, involving a facility that houses 18,546 birds.
The outbreaks involve the Eurasian H5N1 strain, which has led to poultry losses in other parts of the world and first appeared in US wild birds in January. The first outbreak in poultry occurred in Indiana in early February, and since then outbreaks have wiped out more than 24 million poultry, especially turkey in the Midwest.
More detections in wild birds
The USDA's APHIS also reported 44 more detections from wild bird sampling, raising the total to 647 positive samples, mainly involving waterfowl.
The latest are from Colorado, Maine, Minnesota, New York, and North Dakota. The virus was first reported in in a wild bird in South Carolina in January.