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Thread: fearable bird flu

  1. #31
    Join Date
    Jan 1970
    Fremont, CA, U.S.A.


    MAR 8, 2023 7:00 AM
    It’s Time for a Flu Vaccine—for Birds
    Avian influenza has killed millions of birds. Shots to prevent it already exist. Why isn’t the entire poultry industry using them?

    THE WAVE OF avian influenza H5N1—which so far has hit 76 countries, triggered national emergencies, and created the worst animal-disease outbreak in US history—keeps roaring through wild birds and commercial poultry. More than 140 million poultry worldwide have died from the virus or were slaughtered to keep it from spreading, according to the World Organization for Animal Health. And though they are harder to count, the die-offs among wild birds have been catastrophic.

    Something has to put the brakes on. In the US, where losses are close to 60 million, industry experts are talking quietly about taking a step they have long resisted: vaccinating commercial chickens, laying hens, turkeys, and ducks against the flu.

    That doesn’t sound controversial; after all, flu shots for humans are routine, and chickens already receive a handful of vaccinations in the first days of their lives. But only a few countries routinely vaccinate poultry against avian influenza. Introducing a vaccine could trigger trade bans that would crush the enormous US export market, turn sectors of the poultry trade against each other, and possibly provoke consumer uneasiness about food safety.

    Officially, therefore, the industry opposes what would be a drastic step. But privately—none would speak on the record—scientists at poultry companies say they see no other exit strategy. And researchers who work alongside the US industry say there may be little choice but to begin vaccination—but also that the US cannot embark on vaccination alone.

    “Vaccination is being discussed on a global scale, because it would be a global decision,” says Karen Burns Grogan, a veterinarian and clinical associate professor at the University of Georgia’s Poultry Diagnostic and Research Center. (Georgia produces more broilers, or meat chickens, than any other state, about 1.3 billion per year.) “Everyone from the World Organization for Animal Health, to the US federal government, to trading partners, would have to come to a decision.”

    But that decision is by no means guaranteed. Limited stocks of avian vaccines against H5N1 flu were commissioned by the federal government after a huge outbreak in 2015, but they may not curb the currently circulating strain. The US Department of Agriculture has not authorized their use. And expanding the supply enough to protect billions of birds would require a massive manufacturing effort—as well as a significant labor force, because those shots would likely be given by hand.

    The discussion is becoming urgent. H5N1 flu keeps infecting humans—most recently, it killed an 11-year-old girl in Cambodia and sickened her father, though the strain they contracted was different from the one currently ripping through birds, and there was no indication the disease spread from them to others. It is rapidly adapting to mammals, most recently killing sea lions off the coast of Peru and minks being farmed in Spain.

    H5N1 flu is also killing an uncountable but presumably vast number of wild birds, a change from its historic pattern in which wild birds carried the virus but were not sickened by it. “The impact on wild bird populations is unprecedented,” says Peter Marra, an ornithologist and director of the Earth Commons Institute at Georgetown University. “Massive numbers of gannets and other species have vanished. And this is not just in the US, it’s in the entire Western Hemisphere, throughout Europe, and we assume in Africa.”

    And outbreaks in poultry are increasing, even though the industry has tried to harden its biosecurity practices. Those outbreaks represent enormous animal suffering: The fast-moving disease is so gruesome that a prominent expert once called it “chicken Ebola.” Plus, a subset of American veterinarians claims a common method of culling chickens to prevent disease spread—turning off ventilation so that birds die of heat stroke—is cruel. Then, there’s the impact on the food supply: Flock losses just among laying hens last year cut the availability of eggs by 29 percent while doubling prices.

    The devastation among those hens hints at complexities that make vaccination challenging. Every type of commercial poultry is allowed to live to a different age depending on its purpose: Broilers grow to full size in six to seven weeks, turkeys take about six months to get to market weight, and layers and broiler breeders (meat chickens’ parents) are allowed to live a year or more, because hens can’t produce eggs until they’re about 26 weeks old. It’s odd but notable that the longer-lived varieties, layers and turkeys, seem to account for more of the losses from flu. (That may partly be an artifact of layer farms housing such huge numbers of animals—millions per property—that the arrival of the virus takes out many more birds.) So it makes sense that egg and turkey operations would benefit the most from vaccines.

    But eggs and turkeys don’t account for most of the US international trade in poultry. Broilers do: meat, and also spare bits such as feet that Americans don’t care to consume. Broiler meat exports earned more than $5 billion in 2021, according to the USDA. Meanwhile, multiple countries that buy US chicken have long refused to accept meat from vaccinated broilers, arguing that the immune response to vaccination and flu infection is so similar that safe birds cannot be distinguished from carriers. In other words, the US poultry sector that least needs a vaccine would have the most to risk, economically, from using one.

    The intensity of H5N1’s onslaught around the world may be changing that calculus. Last fall an international meeting in Paris explored “removing unnecessary barriers” to avian flu vaccine use. In November, the European Union issued new regulations permitting poultry vaccination under certain conditions; they go into effect this month. Since the beginning of the year, countries in Central and South America, where H5N1 just arrived, have announced they will begin vaccinating poultry.

    And late in 2021, the USDA authorized a five-year research project intended to search for new vaccines against avian flu, determine how to prove that they work, and map whether the use of such shots drives the flu virus toward mutations that vaccines would not protect against.

    A segment of the flu research community has argued for years that there’s a clear way to distinguish vaccinated birds from infected ones. The strategy, called DIVA (for “differentiating infected from vaccinated animals”), creates a molecular marker by swapping out one protein in whatever circulating strain is used to make the vaccine. When vaccinated chickens are tested, they display antibodies to that substitute strain instead of the wild type, demonstrating that their immunity comes from the vaccine and thus that they are safe to trade. The strategy was twice used in Italy, in 2000 and 2001, to shut down poultry outbreaks caused by flu strains H7N1 and H7N3.

    “Other countries always said that the costs attached to vaccination—because of the vaccine itself, but also because of the testing and the potential restrictions on movement—weren't worthwhile,” says Ilaria Capua, a virologist and senior fellow for global health at Johns Hopkins SAIS Europe in Bologna, who proposed the system’s use in Italy while at the Istituto Zooprofilattico Sperimentale delle Venezie. “But the trade barriers can be nullified if you apply a system that tells you that a flock is vaccinated and has not been exposed to the virus.”

    Use of the DIVA system lapsed in Italy because that multiyear wave of H7 strains faded (though not before killing a Dutch veterinarian), and because other countries that were thought to be at risk at the time didn’t have the national budgets or lab capacity to create something similar. The context is different now, given how H5N1 flu has spread worldwide. The number of poultry and wild bird species it has been able to attack isn’t only a measure of the destruction it is wreaking—it’s also a signal that the virus is finding many more hosts in which it can mutate toward more virulent forms.

    Experts say recognizing that reality makes poultry vaccination more urgent. It’s always been known that flu spreads from wild birds to domesticated ones, on ponds or in droppings or via small birds that can squeeze past fan covers. But it’s also possible that flu spreads to wild birds in those moments. And while the logistics of vaccinating birds in the wild are unfathomable, vaccinating the ones close to home is within our grasp.
    All I know is that I haven't had any eggs in months...
    Gene Ching
    Author of Shaolin Trips
    Support our forum by getting your gear at MartialArtSmart

  2. #32
    Join Date
    Jan 1970
    Fremont, CA, U.S.A.

    Still an issue

    China’s ‘best defence’ is poultry vaccine as bird flu spreads from Europe, Africa
    International research team led by University of Hong Kong finds epicentre for deadly H5N1 virus has shifted, carried across the world by wild birds
    With infections recorded across 5 continents, including Antarctica, penguins and marine and land-based mammals are ‘at risk’
    Holly Chik

    Published: 4:00pm, 19 Nov, 2023

    The deadly virus behind bird flu has become better adapted to wild birds and is shifting from China to Europe and northern Africa, in what a study led by the University of Hong Kong (HKU) has called “an environmental disaster”.

    The team, which included researchers in Australia, Egypt, France, the United Arab Emirates and the United States, found that recent outbreaks suggested the epicentre for the H5N1 virus had extended beyond Asia.

    In a paper published by the peer-reviewed journal Nature, the researchers said the virus had also become more persistent in wild bird populations, driving the evolution and spread of new strains, putting marine and land mammals at risk across the world.

    “Since November 2021, this H5N1 virus has caused unprecedented outbreaks in diverse wild bird species across five continents and a significant rise in incidental infections in wild carnivores, mink farms and marine mammals,” they said.

    Lead author Vijaykrishna Dhanasekaran, who heads the HKU pathogen evolution lab, urged China to guard against strains of the virus arriving from Europe by keeping up its vaccination programme against bird flu infections among the country’s flocks.

    “Especially since the emergence of H7N9 in 2013 … the control in China has become really good with mass application of H5 and H7 vaccines. That is one of the reasons the recent resurgence was not in China,” he said.

    “They need to sustain it because now the viruses are coming back from Europe. [China should] continue the vaccination system so that we can keep eliminating the virus.”

    H5N1 first emerged in China in 1996 and was the first virus to establish sustained transmission in domestic poultry. After years of being largely confined to Asian poultry networks, recent outbreaks have emerged further afield.

    On the rare occasions the virus appeared in Europe and Africa, it was carried there by wild birds but would die out after a few months because H5N1 was not as adaptive to wild populations.

    “However, in the past two years we have seen extensive outbreaks – they’re doubling,” said Dhanasekaran, who is also an associate professor with the HKU school of public health.

    “It’s an environmental disaster in terms of the number of wild birds that have been infected. The virus is also spreading to new regions via these migratory flyways.”

    In September, three adult harbour seals in Puget Sound, on the northwestern coast of Washington state, tested positive for the H5N1 virus, according to the US National Oceanic and Atmospheric Administration.

    It was the first time the highly pathogenic bird flu was reported in marine mammals on the US West Coast.

    Last month, concerns were raised that penguins and other local species could be at risk after H5N1 was detected in the Antarctic region for the first time.

    The virus was probably carried to Antarctica by migratory birds returning from South America, where there has been a high number of bird flu cases, according to the British Antarctic Survey.

    Dhanasekaran said the H7 and H9 virus groups mainly infected chickens, while the biggest difficulty in controlling the H5 viruses was that they affected aquatic and terrestrial poultry differently.

    “When [H5] is infecting … poultry, it can kill chickens but it does not kill ducks. It is naturally adapted to ducks so when it is circulating in the live bird markets, we can never be sure until it infects chickens and they start dying,” he said.

    The paper warned that the scale of H5 outbreaks in wild birds had been escalating beyond Asia since 2014. The researchers said recent incidences in African and European bird populations suggested the epicentre had also extended beyond the Asian region.

    “It is necessary to enhance global surveillance and improve multifaceted mitigation strategies for outbreak prevention and response,” the scientists said.

    The World Health Organization recorded 1,566 cases of human infection and at least 613 deaths from the H7N9 virus between 2013 and 2018. China remained the epicentre of the virus until 2016.

    A 2021 study by the State Key Laboratory of Veterinary Biotechnology in Harbin, northern China, identified five waves of human infection caused by the H7N9 bird flu virus, and confirmed that it caused only mild infections in ducks while being highly lethal to chickens.

    The Harbin researchers noted that “further human cases have been successfully prevented since September 2017 through the use of an H7N9 vaccine in poultry” but the virus had not been eradicated from poultry.

    They found that the H7N9 viruses isolated in 2019 were antigenically different from the vaccine strain used to control the virus in poultry. “Replication of these viruses cannot therefore be completely prevented in vaccinated chickens.”

    Meanwhile in Britain, scientists proposed gene editing as a possible way to breed chickens that are partially resistant to bird flu, in a paper published by the peer-reviewed journal Nature Communications in October.

    The team said it was able to restrict the virus from infecting chickens by altering a small section of their DNA. The researchers found fully grown chickens were resistant to a very low dose of the flu from infected birds, but not at doses 1,000 times higher.

    Co-author Mike McGrew, personal chair of avian reproductive technologies at the University of Edinburgh’s Roslin Institute, said gene editing “promises a new way to make permanent changes in the disease resistance of an animal”.

    “This can be passed down through all the gene-edited animals to all the offspring so it would protect the poultry and reduce risk to the poultry farmers and wild birds,” he said.

    Wendy Barclay, head of the department of infectious diseases at Imperial College London and the study’s other author, said her group discovered a gene called ANP32 which was “absolutely essential” to supporting the virus when it was inside the cell.

    “If you could prevent the protein from being used [to help viruses replicate] by gene editing, the virus would not be able to replicate. This strategy could be used not just for H5N1 bird flu, but for any of the strains, because it is fundamental to the way that the virus works,” she said.

    The British scientists monitored the gene-edited birds for more than two years and said they showed no adverse effects on health or egg-laying productivity.

    They cautioned that further study would be needed to ensure animal health, and that multiple edits of the gene family might be needed to eliminate the possibility of viral evolution.
    Not to lessen the magnitude of this crisis, but the author's name is Chik?
    Gene Ching
    Author of Shaolin Trips
    Support our forum by getting your gear at MartialArtSmart

  3. #33
    Join Date
    Jan 1970
    Fremont, CA, U.S.A.


    Oh man, this is our backyard.

    Bird Flu Continues to Batter Sonoma County Poultry Industry Amid Big New Outbreak This Week
    Juan Carlos LaraRiley Palmer
    Dec 21

    Thousands of chickens gather and lay eggs in an organic hen house at Sunrise Farms in Petaluma on Aug. 25, 2010. (Paul Chinn/San Francisco Chronicle via Getty Images)

    More cases of avian flu were detected this week at three additional Sonoma County poultry operations near Petaluma, including one that houses nearly half a million birds, hitting the largest facility since the disease began ripping through this area late last month.

    That brings the total number of sites here to seven, prompting the euthanization of more than 1 million birds, according to the U.S. Department of Agriculture, which tracks the outbreaks.

    Highly Pathogenic Avian Influenza is typically spread from wild birds to farm-raised flocks through direct or indirect contact. The virus is often deadly to birds but is rarely transmitted to humans.

    Bill Mattos, president of the California Poultry Federation, said the ongoing winter migration of wild birds has contributed to the transmission of the virus.

    “I haven’t really got any reports from the state veterinarian other than the fact that they had hoped, like us, this wouldn’t have been so severe already,” Mattos said. “We’re just starting the winter months. It isn’t even halfway through.”

    Sonoma County Supervisor David Rabbitt, who represents the district where all seven affected farms are located, said these outbreaks are financially and emotionally devastating to farmers who have to kill off and dispose of their entire flocks whenever the disease is detected.

    “It’s just tragic. No other way to put it. I mean, the consequences of one infection … you lose your entire flock,” said Rabbitt, who confirmed that Sunrise Farms owns the site of the biggest outbreak.

    Adding to the financial burden, he said, farmers at affected sites must also wait 120 days or pay for environmental testing before repopulating their flocks.

    “The biggest concern of the producers is losing their customers, losing their clients, the markets,” Rabbitt said. “Because the markets are gonna have eggs on the shelves, and if they don’t get them from the producers right around Petaluma, they’re gonna get them from someone else.”

    Rabbitt said the county has some resources to help struggling farmers but not nearly enough to cover the sizable damage already inflicted on the county’s $50 million poultry industry.

    He added that two of the largest feed distributors in this rural area about 40 miles north of San Francisco have also lost roughly 60% of their business now that so many farms have been emptied and the demand for feed has plummeted.

    The avian flu has been reported among farm-raised flocks at five other counties throughout the state in recent months, but only Merced County has seen a higher number of affected birds. Last week, farmers in a single facility in that county had to euthanize more than 1.3 million birds after the virus was detected.

    Agriculture officials are also investigating a suspected outbreak at another Central Valley facility that houses more than 1 million egg-laying birds, according to Mattos of the California Poultry Federation.

    “It’s a lot of birds, it’s terrible,” he said.
    Gene Ching
    Author of Shaolin Trips
    Support our forum by getting your gear at MartialArtSmart

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