Bird flu associated with hundreds of seal deaths in New England in 2022, researchers find

[Treyfish]

MARCH 15, 2023
Bird flu associated with hundreds of seal deaths in New England in 2022, researchers find


by Tufts University
Researchers at Cummings School of Veterinary Medicine at Tufts University found that an outbreak of highly pathogenic avian influenza (HPAI) was associated with the deaths of more than 330 New England harbor and gray seals along the North Atlantic coast in June and July 2022, and the outbreak was connected to a wave of avian influenza in birds in the region.


The study was published on March 15 in the journal Emerging Infectious Disease.

HPAI is more commonly known as bird flu, and the H5N1 strain has been responsible for about 60 million poultry deaths in the U.S. since October 2020, with similar numbers in Europe. The virus was known to have spilled over from birds into mammals, such as mink, foxes, skunk, and bears, but those were mostly small, localized events. This study is among the first to directly connect HPAI to a larger scale mortality event in wild mammals.
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The co-first authors on the paper—virologist and senior scientist Wendy Puryear and post-doctoral researcher Kaitlin Sawatzki, who both work in the Runstadler Lab at Cummings School—have been researching viruses in seals for years.

They credit their findings in the new study to a unique and robust data set made possible by a collaboration with wildlife clinics and rehabilitation and response or...
:tiphat:https://phys.org/news/2023-03-bird-flu-hundreds-deaths-england.html​​​​​​

 

[Treyfish]

Bird Flu Outbreak Killed New England Harbor Seals, Raising Alarms for Humans
Ernie Mundell

Published on March 15, 2023

WEDNESDAY, March 15, 2023 (HealthDay News) -- A strain of avian (bird) flu appears to be killing seals off the New England coast, heightening fears among scientists that mammal-to-mammal transmission could be happening.

If so, it would be a step towards something health experts have long dreaded: A strain of H5N1 bird flu that might spread easily among people, with potentially devastating effects.

"We report an HPAI A (H5N1) virus outbreak among New England harbor and gray seals that was concurrent with a wave of avian infections in the region," said a team led by Dr. Wendy Puryear. She is a virologist at the Cummings School of Veterinary Medicine at Tufts University in North Grafton, Mass.

Overall, there were 164 known cases of deaths to harbor seals and 11 such cases of gray seals in Maine during June and July of 2022. Puryear and her team reported their findings March 15 in Emerging Infectious Diseases, a journal of the U.S. Centers for Disease Control and Prevention.

The "unusual mortality event" among the seals tracked closely with the second wave of an H5N1 outbreak among Atlantic coast seabirds last year, the researchers noted.

That outbreak had also spread to millions of commercial poultry, resulting in a disease-limiting cull of over 70 million domestic poultry in the United States.

The presence of highly pathogenic avian influenza (HPAI) A (H5N1) bird flu was detected in samples taken early in 2022 by the team from over a thousand New England seabirds. The disease continued to show up among birds throughout the summer.

Puryears' group also used swab tests to monitor any presence of H5N1 in seals. Tests taken of 132 stranded seals in the first half of 2022 showed no sign of the virus in the mammals, but by June and July the strain was detected in 19 harbor seals sampled.

"We're always concerned when it's in mammals, just because they're closely related to humans," Dr. Ryan Miller, an infectious disease doctor at the Cleveland Clinic in Ohio, explained recently to HealthDay.

Potential threat

......

Did the New England seals in last year's outbreak pass H5N1 to each other? That's still unclear, according to the Tufts team.

All they can say at this point is that seals got infected "through environmental transmission of shed virus" with seabirds as the originating source. The affected seals rarely prey on seabirds or scavenge bird remains, however, so seal-to-seal transmission of H5N1 remains possible.


If individual seals did get the virus from close proximity to seabirds, the ease at which the virus transmitted between species is troubling, Puryears' group noted. In addition, novel mutations in the HPAI A (H5N1) strain were noted between infected seals, including certain changes "associated with mammal adaptation," the study authors added.

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The infections noted in the New England seals aren't the only sign that mammal-to-mammal transmission is happening: A mink farm in Spain suffered an H5N1 epidemic last October, one of the first large outbreaks of the virus that was apparently driven by mammal-to-mammal transmission. Nearly 52,000 mink on the farm were culled as a result.

"These mink are jammed very, very closely together, by and large, and it spread among the mink," Dr. William Schaffner, medical director of the National Foundation for Infectious Diseases, explained recently to HealthDay. "Well, that's a little bothersome because this virus is not supposed to spread very much in mammals, although the mink have some viral receptors that are more accepting of this virus than some other animals," he noted.

"Fortunately, all the human beings who worked on that mink ranch were tested and were found to be negative, so it didn't get to the people," Schaffner added.

Crossover risk

The risk to humans comes from the possibility that one of these avian flu strains will infect some animal — a pig, for instance — that is also susceptible to human influenza, Schaffner explained.

"When the two of them are together in the pig, it's like being in a test tube. Those two viruses can exchange genetic components, and it's possible for a bird flu virus to pick up that genetic capacity from the human virus of being able to spread readily from person to person," Schaffner said.

"Now, if that happens, then you have an incipient pandemic because the world's population would be susceptible to that virus and it could spread globally," Schaffner continued.

Other experts urge vigilance, but believe there's no immediate threat to people.

"It's a potential risk. The likelihood of that happening is, I think, still quite low compared to other risks that we have. But it's a real risk and it's something obviously we have to be prepared for, something we have to watch very carefully," said Dr. Aaron Glatt, chief of infectious diseases and chair of medicine at Mount Sinai South Nassau in Oceanside, N.Y.

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:tiphat:
https://consumer.healthday.com/bird-flu-2659593836.html

 

[Toaster2]

Link to paper:

https://wwwnc.cdc.gov/eid/article/29/4/22-1538_article

 

[sharon sanders]

Please see:

Preprint: Outbreak of Highly Pathogenic Avian Influenza H5N1 in New England Seals - August 2022

"Unusual number" of seal deaths off Maine coast linked to bird flu - July 2022

Maine: Seal Deaths Linked To Avian H5N1 - July 2022

 

[Treyfish]

Study of H5N1 avian flu seal deaths reveals multiple lineages
Today at 3:57 p.m.
Lisa Schnirring
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Deaths of seals from H5N1 avian influenza in seals stranded on New England beaches last summer stoked growing concerns about the susceptibility of mammals, including humans, to the virus, and now researchers have shared detailed genetic findings from both the seals and birds from the environment, noting a range of virus lineages in the animals and a low species barrier.

The event marked the first known H5N1 detection in marine mammals. Similar events were reported in Canada, Peru, and—according to media reports—Russia. Researchers based at Tufts University published their findings today in Emerging Infectious Diseases. The investigation included key contributions from wildlife clinics and rehabilitation groups in the region, including an extensive regional mammal stranding network run by the National Oceanic and Atmospheric Administration (NOAA).

New England had two waves of H5N1 activity in wild birds in 2022, one that peaked in March and the other that began in June. The H5N1 detections in seals were reported in the second wave, prompting NOAA to declare an unusual mortality event, with more than 330 stranded animals, many found dead.
Low species barrier in seals


In a Tufts University news release, the first two authors of the paper said the collaboration with the groups provided unique and robust data. Wendy Puryear, PhD, a virologist and senior scientist at Tufts, said, "We have a better resolution and greater depth of detail on this virus than before because we were able to sequence it and detect changes almost in real time." She added that the group had pairs of samples, sometimes from a bird and seal at the same beach.

They found a wide range of flu viruses, including at least three strains that crossed the Atlantic, and tracked consistent infection waves in birds. Scientists also screened seals that were and weren't sick.

Kaitlin Sawatzki, PhD, a postdoctoral researcher with Tufts, said, "Because of the genetic data that we gathered, we were the first to see a strain of the virus that's unique to New England. The data set will allow us to more meaningfully address questions of which animals are passing the virus to which animals and how the virus is changing."

During the seal morality event, gulls were hit hard by the virus. Researchers said the gulls can transmit the virus through different routes, including contact with sick birds or exposure to contaminated environments. In the paper, the group wrote that, unlike other mammals known to contract H5N1, seals don't typically feed on birds.

They said data suggest transmission to seals occurred frequently and that there was a low species barrier in seals. In the seal samples, they saw novel amino acid changes, including some linked to mammal adaptation. And wh....:tiphat: https://www.cidrap.umn.edu/avian-in...ian-flu-seal-deaths-reveals-multiple-lineages

 

[Treyfish]

Bird Flu Outbreak Linked to Thousands of Seal Deaths in New England [CDC]

By Louise Franco Apr 05, 2023 12:53 AM EDT

Bird flu outbreak over the years have affected several millions of avian species worldwide.

,,,,
In a recent study, the Centers for Disease Control and Prevention (CDC) reported the outbreak involving HPAI type 5 called hemagglutinin and type 1 neuraminidase, infecting New England gray seals and harbor seals in the United States.

Initial reports said hundreds of seals have died from low pathogenic avian influenza, also called the North American H5N1, which is common among wild birds.

However, the CDC assessment has shown thousands of New England seals, instead of hundreds, have died from the current bird flu outbreak.

The latest figure is only in addition to the recorded death toll of over 70 million domesticated birds from the 2.3.4.4b variant of H5N1.

The latest findings confirmed previous concerns that bird flu could jump to other animal species.
New England Bird Flu Outbreak

The CDC study was published in the journal Emerging Infectious Diseases for the issue April 2023.



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The research team reported the spillover of H5N1 into marine mammals in the northeastern region of the US, which coincides with the presence of the disease in wild bird populations.

Due to the growing threat, the team recommends the monitoring of both wild coastal birds and marine mammals like the New England seals.

New England Seal Deaths


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The samples were found in regions where there are suspected avian influenza outbreaks among different seabird species like cormorants, eiders, gulls, and terns, as cited by the website News Medical.

Furthermore, the team asserted that birds are not the typical prey of seals but some interactions between the two animal groups may have allowed the virus to jump from the avians to the large mammals.

In addition, the CDC study showed transmissions of the virus between infected and uninfected seals even without passing through the birds.

While human infections related to H5N1 are relatively rare, the World Health Organization (WHO) reported as of March that there have been a total of 868 human cases of bird flu infections from January 2003 to January 2023.

Out of all these cases, 457 or 53% were fatal, the WHO noted.
:tiphat:https://www.natureworldnews.com/arti...​​​​

 

[sharon sanders]

Please see:

Emerg Infect Dis . Highly Pathogenic Avian Influenza A(H5N1) Virus Outbreak in New England Seals, United States

 

[Treyfish]

Avian Flu Outbreaks in Marine Mammals Mark New Era for Deadly Virus


A highly pathogenic strain of avian influenza has killed thousands of wild birds and is now infecting seals and other marine mammals. Researchers know the virus can jump from birds to mammals, but they are on alert to see if it can be transmitted from mammal to mammal.

BY ANDREW S. LEWIS • MAY 4, 2023
Last June, the phones at Marine Mammals of Maine began ringing — a lot. People walking the craggy shoreline of Casco Bay, which stretches north and south of Portland, were reporting sick or dead seals. Late spring and early summer, as pups begin to set off on their own, are usually the rescue and rehabilitation center’s busiest time, but the volume of calls kept increasing. “We were dealing with three times the number of animals we would normally be dealing with,” says Lynda Doughty, the center’s executive director.

One harbor seal’s behavior stood out. The animal was, Doughty recalls, “neurologic” — its weight and overall nutrition were fine, but in addition to coughing and sneezing, it was twitching and seemed disorientated. The young male’s condition was rapidly declining, and Doughty’s thoughts turned to the many recent reports of wild birds — like raptors and gulls — infected with a new strain of H5N1, a highly contagious avian influenza. She worried that whatever ailed the rapidly declining seal could spread to the other seals crowding the center and made the difficult decision to euthanize. Then she called Wendy Puryear.

Avian influenza previously didn’t appear to spread between mammals. But this new variant has proven different.​

​.......:tiphat:https://e360.yale.edu/features/avian-flu-mammals-birds-seals​​​​​​