Dec 8, 2022 08:19 AM
https://hakaimagazine.com/news/the-rampa...territory/
EXCERPTS: For months, I have been following the media coverage of the devastating outbreak of avian influenza as it’s killed thousands of seabirds in Scotland. In the summer of 2022, gannets and skuas on Scotland’s remote isles started behaving oddly. They walked in circles as if intoxicated. Their heads swelled. They dragged their limp wings at their sides, feathers grazing the ground. At a time when they should have been breeding and raising new life, they were dying. Scientists and birdwatchers had a front-row seat to an ecological disaster. More than two-thirds of the world’s gannets and great skuas—birds that migrate across the Atlantic Ocean from eastern North America to western Europe—are feared to have been lost.
As the influenza tore through seabird colonies near my home, it also spread over the Atlantic into eastern Canada, through the United States, and, most recently, into South America, jumping into new hosts as it went. Eagles, pelicans, and even mammals such as red foxes, seals, and bears have died after coming into contact with infected birds.
All of this is incredibly unusual. Seabirds shouldn’t die from the flu. The type of influenza virus that infects birds—known as influenza A, or bird flu—is traditionally mild; most birds don’t show any sign of sickness. Its natural habitat is within the digestive systems of seabirds and waterfowl, such as ducks and geese. It spreads through bodily fluids and fecal matter in the water. It’s a natural part of wetland and coastal ecosystems.
But this outbreak has killed thousands of seabirds. It has also survived through the summer, a season usually free from influenza in the northern hemisphere. And it jumps into mammals, an entirely new host, with aplomb. The situation has scientists wondering: is this the new norm? And if so, should we be concerned that it will adapt to, and spread through, humans next?
[...] In short, this outbreak of bird flu is unprecedented. What happens next is anyone’s guess.
“It might mean that the virus is just going to become endemic [in wild birds] for a while,” says Digard. The birds that have already survived infection might harbor some innate resistance, and in time that immunity may spread. In the meantime, this highly lethal flu will be a constant threat to avifauna around the world.
The virus’s persistence and geographic spread also raise the risk of it spilling over into humans. “It’s hard to predict, but there’s no reason why it can’t happen,” Digard says.
As ominous as this bird flu appears, there are also signs that this virus is evolving away from human transmissibility. Samantha Lycett, a molecular epidemiologist at the University of Edinburgh who studies the genetic evolution of influenza, has yet to see the sort of mutations that allow the virus to threaten our bodies.
To Lycett, H5N1-HPAI-clade 2.3.4.4b appears content in wild birds. “It’s doing quite well for itself,” she says. “You are getting these spillovers [into mammals], but is that basically because there’s just a lot of [the virus] about? I think that probably is the case.” (MORE - missing details)
EXCERPTS: For months, I have been following the media coverage of the devastating outbreak of avian influenza as it’s killed thousands of seabirds in Scotland. In the summer of 2022, gannets and skuas on Scotland’s remote isles started behaving oddly. They walked in circles as if intoxicated. Their heads swelled. They dragged their limp wings at their sides, feathers grazing the ground. At a time when they should have been breeding and raising new life, they were dying. Scientists and birdwatchers had a front-row seat to an ecological disaster. More than two-thirds of the world’s gannets and great skuas—birds that migrate across the Atlantic Ocean from eastern North America to western Europe—are feared to have been lost.
As the influenza tore through seabird colonies near my home, it also spread over the Atlantic into eastern Canada, through the United States, and, most recently, into South America, jumping into new hosts as it went. Eagles, pelicans, and even mammals such as red foxes, seals, and bears have died after coming into contact with infected birds.
All of this is incredibly unusual. Seabirds shouldn’t die from the flu. The type of influenza virus that infects birds—known as influenza A, or bird flu—is traditionally mild; most birds don’t show any sign of sickness. Its natural habitat is within the digestive systems of seabirds and waterfowl, such as ducks and geese. It spreads through bodily fluids and fecal matter in the water. It’s a natural part of wetland and coastal ecosystems.
But this outbreak has killed thousands of seabirds. It has also survived through the summer, a season usually free from influenza in the northern hemisphere. And it jumps into mammals, an entirely new host, with aplomb. The situation has scientists wondering: is this the new norm? And if so, should we be concerned that it will adapt to, and spread through, humans next?
[...] In short, this outbreak of bird flu is unprecedented. What happens next is anyone’s guess.
“It might mean that the virus is just going to become endemic [in wild birds] for a while,” says Digard. The birds that have already survived infection might harbor some innate resistance, and in time that immunity may spread. In the meantime, this highly lethal flu will be a constant threat to avifauna around the world.
The virus’s persistence and geographic spread also raise the risk of it spilling over into humans. “It’s hard to predict, but there’s no reason why it can’t happen,” Digard says.
As ominous as this bird flu appears, there are also signs that this virus is evolving away from human transmissibility. Samantha Lycett, a molecular epidemiologist at the University of Edinburgh who studies the genetic evolution of influenza, has yet to see the sort of mutations that allow the virus to threaten our bodies.
To Lycett, H5N1-HPAI-clade 2.3.4.4b appears content in wild birds. “It’s doing quite well for itself,” she says. “You are getting these spillovers [into mammals], but is that basically because there’s just a lot of [the virus] about? I think that probably is the case.” (MORE - missing details)