H5N1 confirmed in samples from Manitoba bird die-off, but researcher says this brings some relief

Warning: This story contains an image of a dead swan.

The Canadian Food Inspection Agency has detected a highly contagious strain of avian influenza in several samples collected in southern Manitoba, causing what scientists have described as an unprecedented death toll of birds.

The carcasses of about 500 birds, mostly Canada geese, were found near streams in southern Manitoba in early December. Separate groups of dead birds were found near the Red River, north of Winnipeg’s Perimeter Highway, but The highest concentrations were found in a group of ponds in Niverville..

Canadian Wildlife Service biologist Frank Baldwin told CBC News on Thursday that samples from the birds were sent to the Canadian Food Inspection Agency after they tested positive for avian influenza. Also known as bird flu To determine the type of infection.

A spokesperson for the federal agency told CBC that it had submitted samples of 39 wild birds to the National Center for Exotic Animal Diseases for testing on December 11.

The food inspection agency said lab analysis confirmed that 38 samples were positive for the highly pathogenic H5N1 strain of bird flu.

Hannah Wallace, a University of Manitoba researcher who specializes in viral immunology, said H5N1 is responsible for significant illness and mortality in birds, but she was relieved that the samples tested positive for that strain.

scientists did not have before this Bird flu caused high mortality rates in swans, and Wallace was concerned that the virus might mutate into a different type, and potentially be more dangerous to birds and humans.

There have been cases of H5N1 in people, and “the concern is that a virus that was a mixture of bird and human origin will essentially become a mixture of both.”

“This could potentially have more serious impacts on human populations.”

The samples collected tested positive for the H5N1 strain that is circulating primarily in domestic poultry and wild bird populations in North America, according to the food inspection agency.

“It’s not a surprise at all,” Wallace said. “We say, ‘Okay, we’ve got this.’ “That’s exactly what we’re dealing with.”

H5N1 was first detected in Canada in late 2021. Most birds in Canada have already been exposed to it, giving them some level of pre-existing immunity, Wallace said.

Birds that are weak or receive less food may be more likely to become infected with H5N1. Wallace wonders whether this was the case with the birds dying in southern Manitoba.

After a mild initial decline, they may have remained in the province too late in the season, and then faced cold weather and food shortages.

living in environment

Studies have also shown that avian influenza can survive in the environment, even after birds have migrated for the season, Wallace said.

Although she thinks it’s unlikely the virus will still be in the water where dead birds were found last year, it could still be in ponds or river sediments. He said the virus can survive until spring even in cold temperatures.

Baldwin of the Canadian Wildlife Service says avian influenza behaves differently every year. Sometimes, birds have high levels of antibodies to fight it.

“But we don’t know exactly how long the protection lasts,” he said.

“I think it’s probably possible that we will see some mortality in snow geese and Ross’s geese that migrate from Canada on their way to the Arctic in April and May.”

Avian influenza has been a matter of concern not only for scientists, but also for poultry farmers in the province for years.

Rod Wiebe, board chair of the Manitoba Chicken Producers, says the virus is a health challenge because of how contagious and deadly it is.

Although farmers can help prevent transmission through advanced bio-security measures, bird flu is harder to control when wild birds come into contact with it, he said in an interview on Thursday.

Wiebe said farmers are generally less concerned about it during the winter, but bird flu peaks during fall and spring migration.

“Birds roam anywhere. So they can be near farms… and they can spread the virus,” he said.

Candace Lillick, owner of Breezy Birds Farm in Morris, Maine, said wild birds have been a concern as she tries to protect her poultry farm.

“Over the years, if a bird lands here because it’s a pond, I do everything in my power to let them go,” she said.

But there is also a need to change the way it operates to keep infectious viruses away from its farms.

Lylic is strict about not allowing customers to visit the farm, instead opting for delivery. When trucks come to the field their tires are sprayed.

“I fear losing my livelihood and my birds,” Lilik said. “They’re family to me.”