Avian influenza has been detected in Alaskan wild birds and the fox

Avian influenza has been detected in Alaskan wild birds and the fox

By Megan Gannon
North America is currently experiencing one of the largest recorded outbreaks of a highly contagious and deadly strain of bird flu, also known as H5N1flu. More than 38 million domestic birds have been culled in the United States and Canada, but what makes this outbreak unprecedented is its toll on wild birds.
That’s what an audience of local subsistence hunters, scientists, recreational birders and other Alaskans heard during last week’s Flag of the Fjords presentation organized by the UAF Northwest Campus. The lecture came just in time as several cases of highly pathogenic avian influenza have been documented in wild birds in Alaska. Residents of the Bering Strait region have been asked to look out for diseased birds – and possibly mammals, too. In at least one case, in Onalaska, the virus was detected in a red fox and pet owners were warned to keep their animals away from dead birds.
The current outbreak, which hit North America in late 2021, is “only the second outbreak affecting wild birds in the United States and Canada,” said first speaker, Andy Ramey, a research wildlife geneticist at the USGS in Anchorage. “The number of wild bird detections in the past six months is more than 15 times higher than the total number of highly pathogenic and wild bird flu cases in Canada and the United States during all previous outbreaks,” Rami said.
Rami provided comprehensive background information on the virus to help contextualize the current outbreak.
He explained that there are some types of bird flu that occur naturally in wild birds, and birds often appear healthy when infected with these strains.
“Not all bird flu infects or kills birds,” Rami said. Sometimes avian influenza viruses that occur naturally in wild birds are spread to domestic poultry. Oftentimes, poultry infected with these types of viruses also appear to be healthy.”
The small portion of bird flu viruses that cause morbidity in chickens and turkeys are called highly pathogenic avian influenza viruses, he said. “The tendency of viruses to cause serious illness and death in birds, or to become highly contagious, usually only occurs after viruses are introduced into poultry,” Rami said.
When these highly pathogenic strains spread, they can lead to the death and destruction of large numbers of domestic birds. To date, more than 350 poultry facilities have been damaged in the United States, with more than 38 million birds culled. More than 1,600 cases of the disease have also been detected in wild birds in the United States and Canada, and most have come from visibly sick or dead birds.
Rami said the spread of highly pathogenic avian influenza from poultry to wild birds has only become common in the past 20 years. Prior to 2002, there was only one outbreak of highly pathogenic avian influenza globally, which occurred in South Africa in 1961. “Things have changed; Rami explained that outbreaks of the disease in wild birds have become more common and geographically widespread, especially after 2005.
Rami said some birds, especially waterfowl like clover and pintail, can carry the virus while still looking healthy. Other birds, especially birds of prey such as eagles, hawks, hawks and owls, appear to be hardest hit by the current outbreak. Signs of illness in wild birds may include lack of coordination, stumbling, inability to stand upright, inability to fly, swimming in circles, a twisted neck or paralysis.
Rob Kahler, a wildlife biologist with the Migratory Bird Management Division of the United States Fish and Wildlife Service based in Anchorage, spoke next. The focus of his talk wasn’t highly contagious bird flu, but rather another worrying trend among wild birds: seabird death events.
“We consider seabirds as indicators of the state of a marine ecosystem, and the health of it [ecosystem]Because seabirds live most of their lives in the sea. “They come ashore only to breed, and this provides an opportunity to monitor long-term population trends.”
Historically, deaths have been rare, associated with strong El Niño events or diseases, but since 2015, deaths have become annual events, mostly in the Bering Strait, Bering Sea, and Aleutian Seas, Kahler said.
He also told the public that when deaths occur, every dead bird received by the National Wildlife Health Center is scanned and tested for bird flu. Kahler emphasized that highly contagious avian influenza is not usually found among seabirds.
The first question from the audience came from a caller who joined Zoom from Little Diomede, an island filled with colonies of seabirds of species such as crested auklets, lesser auklets, puffins, kittiwakes, and cormorants. Subsistence fishermen use the birds on the island for their meat and eggs. “Are we in danger?” asked the caller. “Are we safe? Are we safely eating the birds we consume every summer?”
Because none of the speakers was a human health professional, they were unable to provide medical advice and were deferred to CDC guidelines. Currently, the Centers for Disease Control and Prevention (CDC) says the virus poses a low risk to humans. To date, one case of the virus has been detected in humans, in a poultry worker in Colorado who had close contact with an infected commercial flock, albeit wearing personal protective equipment. He was largely asymptomatic, and only reported fatigue after he tested positive. Fjord science audiences were reminded to avoid harvesting or handling birds that looked sick, and to document and report any cases of strange behavior or mortality.
“If you can take pictures or make a short video, that is very useful as well,” Ramy said. Please do not pick up carcasses, move dead birds, or attempt to pick up or handle sick birds. Your observations and reports are currently the best way to help document the effects of HPAI during an outbreak.”
Another participant wanted to know how common or rare it was for the disease to be transmitted to mammals. Several cases have now been documented in foxes and skunks in North America.

“This spread among birds and mammals is not uncommon,” Rami said. “It does happen. But when viruses are transmitted to mammals, there is a tendency that there is a growing concern about further spread in mammals. I think what’s happening is not without precedent. It’s unheard of. But it’s also not very common. And it’s something I think many different agencies and many different people are watching him carefully [of]to see what comes next, if anything.”
An audience member from Unalaska joined in and said she had reported a sick vulture there a few weeks ago. She wanted to know if recording and summoning in such incidents was all she could do.
“I think in order to maintain the health and safety of the general public, it is better to have trained personnel responding to these events,” Rami said. “And I think that’s why the guidance was what it is.”
Kahler added that since Alaska is such a huge state, these opportunistic reports from the public are necessary to monitor the situation. “We really owe it to members of the community for providing that information,” he said.
To report unusual observations and concerns about birds, call the US Fish and Wildlife Alaska Sick/Dead Bird Hotline at 1-866-527-3358. The Alaska Department of Fish and Wildlife Health Report can be reached by email at dfg.dwc.vet@alaska.gov. Reports may also be submitted to the local Environmental Watch Network, www.leonetwork.org or locally to Gay Sheffield, UAF Alaska Sea Grant at (907) 434-1149.

2022-06-04 23:06:13

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