Editor’s note: This story was inadvertently cut in Sunday’s edition and is being republished in its entirety.
As Alaska’s wild waterfowl start to migrate south for the winter, some could be carrying a form of the avian influenza virus.
A mallard, trapped in mid-August by Alaska Department of Fish and Game researchers in the Creamer’s Field Migratory Waterfowl Refuge in Fairbanks, tested positive for the H5N2 variety of avian flu. This variety of the virus caused the 2015 bird flu outbreak that killed approximately 43 million farm birds in poultry-raising regions of the Lower 48.
Andy Ramey, a research wildlife geneticist at the U.S Geological Survey’s Alaska Science Center, said the discovery is unusual for at least two reasons: it is the first finding of the virus’ highly pathological type in wild birds in Alaska, and it may have been spread from domesticated poultry to the wild birds, reversing the highly pathogenic type’s usual infection path.
Researchers classify the avian flu virus by its pathogenicity, or likelihood of killing its host. The low pathogenic version of the virus doesn’t cause symptoms and has been found in Alaska’s migratory bird population before. The high pathogenic type can be fatal and contagious, and is more typically found in domestic poultry populations, Ramey said.
“It’s infrequent, but sometimes the low pathogenic viruses go from wild birds into poultry production systems,” Ramey said. “That can be backyard birds, sometimes large poultry holdings. There, viruses of two particular subtypes … have the tendency to become highly pathogenic. That means it kills chickens. It seems that occurs almost entirely in poultry. It’s very rare that one of these viruses spills back over from poultry into wild birds. In fact, this is the first time such a virus was ever detected here in Alaska in wild birds.”
Researchers from the Alaska Department of Environmental Conservation, Alaska Department of Fish and Game and the Alaska Science Center have been trapping and testing wild birds for H5N2 since the 2015 outbreak. According to the U.S Department of Agriculture, 591 wild birds in Alaska were sampled for avian influenza between June 2015 and June 2016.
Ramey said there isn’t enough data on the Fairbanks virus to make solid inferences about its prevalence or origins, though a test by the USDA’s National Veterinary Service lab found it was 99 percent similar to a virus found in Washington state in winter 2014. The sample is currently being genomically tested for more information, Ramey said.
Several different agencies, including the U.S. Department of Agriculture, the Alaska Department of Fish and Game and the U.S Geological Service have begun “a series of carefully coordinated sampling efforts” to determine the prevalence of the highly pathogenic virus by examining birds taken by hunters around the state, Ramey said. Waterfowl hunting season opened Sept. 1. The Alaska State Veterinarian is also monitoring for the virus by testing birds — domestic rather than wild — at agricultural events around the state.
According to a press release from the Alaska Department of Natural Resources, normal meat-handling precautions — cleaning tools and cooking to an internal temperature of 165 degrees Fahrenheit — can protect bird hunters from the virus, which hasn’t been discovered in humans in North America. For poultry raisers, Agriculture and Horticulture Agent Casey Matney of the University of Alaska Cooperative Extension Service recommended a more comprehensive set of “biosecurity” precautions against avian influenza.
Although the virus has never been found in domestic birds in Alaska, it is transmitted through a bird’s saliva and feces, creating an infection risk when poultry are exposed to water or soil where wild birds have also been.
Infected birds could experience swollen heads, nasal discharge, discoordination, depression or sudden death.
“Watch your birds to determine whether they’re sick,” Matney said. “You’ll look for animals that look like they aren’t doing well. Their droppings could be different. Their eyes don’t open all that well, and their head is down.”
Sick or suspicious birds can be reported to the office of Alaska State Veteran Bob Gerluch, or to the University of Alaska Cooperative Extension Service.
Preventative measures Matney recommended include cleaning cages and tools with bleach-water, avoiding giving birds water from outdoor sources such as ponds or lakes, and keeping domestic birds away from places wild birds may visit.
“If their droppings are in there, or they’re eating and drinking from the same place, that’s a potential source of contamination,” Matney said.
Reach Ben Boettger at email@example.com.