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Thousands of birds dying from lethal strain of avian flu - Scotland

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  • Thousands of birds dying from lethal strain of avian flu - Scotland

    4 Jul 2022

    Alex Thomson

    Thousands of seabirds in colonies across the country are dying with bird flu, washing up along our east coast from Scotland down to Suffolk.

    A lethal strain of the virus has found its way from poultry into seabirds and it’s been spreading fast over the last few weeks.

    Defra has set up a taskforce to look at the spread and to try to prevent the deadly H5N1 from becoming pandemic.

    A warning, this report contains images of animal suffering.

    https://www.channel4.com/news/thousa...n-of-avian-flu

  • #2
    I would take issue with this, not what is happening, but the attempt to lay the blame on the human domestic poultry industry and SE Asia in particular. This is not originally a poultry disease, or a disease of seabird populations, its origins are in freshwater birds and has spread from there into poultry and sea birds and, occasionally, mammals. SE Asia is thought to be the original home of all flu, including our seasonal flus, and has the greatest genetic diversity in strains so also has the highest probability of seeding new problem reassortments.

    edit:
    For anyone interested in a more detailed look at the flu genomes in different avian groups, and how they interact, I wrote a number of posts in an old H7N9 discussion thread. The graphic below is taken from that thread and links for the posts can be found in the Zoonotic Edge footnotes in post #2 of Influenza databases need root and branch reform. The Venn diagram should also have another poultry set partially overlapping the Ducks and Other birds sets which is dominated by H9N2 but would be difficult to draw. It should also be noted that while HAs (e.g. H1Nx) may occur in all the groups they are related but genetically not identical but optimised for their group.

    venn2.JPG
    Last edited by JJackson; July 6, 2022, 07:06 AM.

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    • #3
      Originally posted by JJackson View Post
      I would take issue with this, not what is happening, but the attempt to lay the blame on the human domestic poultry industry and SE Asia in particular. This is not originally a poultry disease, or a disease of seabird populations, its origins are in freshwater birds and has spread from there into poultry and sea birds and, occasionally, mammals. SE Asia is thought to be the original home of all flu, including our seasonal flus, and has the greatest genetic diversity in strains so also has the highest probability of seeding new problem reassortments.
      I agree. The experts in the video have the history wrong.

      Great video for visuals on what the current outbreak is doing to the Scotland sea bird populations.

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      • #4
        A brief history of bird flu

        Published online 2019 May 6.

        doi: 10.1098/rstb.2018.0257

        Samantha J. Lycett, Florian Duchatel, and Paul Digard

        ABSTRACT

        In 1918, a strain of influenza A virus caused a human pandemic resulting in the deaths of 50 million people. A century later, with the advent of sequencing technology and corresponding phylogenetic methods, we know much more about the origins, evolution and epidemiology of influenza epidemics. Here we review the history of avian influenza viruses through the lens of their genetic makeup: from their relationship to human pandemic viruses, starting with the 1918 H1N1 strain, through to the highly pathogenic epidemics in birds and zoonoses up to 2018. We describe the genesis of novel influenza A virus strains by reassortment and evolution in wild and domestic bird populations, as well as the role of wild bird migration in their long-range spread. The emergence of highly pathogenic avian influenza viruses, and the zoonotic incursions of avian H5 and H7 viruses into humans over the last couple of decades are also described. The threat of a new avian influenza virus causing a human pandemic is still present today, although control in domestic avian populations can minimize the risk to human health.

        This article is part of the theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: approaches and important themes’. This issue is linked with the subsequent theme issue ‘Modelling infectious disease outbreaks in humans, animals and plants: epidemic forecasting and control’.

        ... CONCLUDING REMARKS

        In this brief history of bird flu, we have seen that current avian influenza virus strains have been circulating and diversifying in wild bird populations for at least the last 100 years. Wild migratory birds can transport IAV along their migration routes, and contact between wild and domestic avian populations sometimes results in transmission between the two. Direct transmission of the virus from wild birds to humans appears to be very rare (or non-existent), presumably due to the low frequency of contact between the two populations; however, transmission from domestic avian species to humans does occur, especially in live bird markets in Asia. It is clear that H5 and H7 viruses have the capacity to evolve (on multiple occasions) an HPAI phenotype, probably as result of transmission in high bird density settings and the susceptibility of chicken and other domestic Galliformes species. In recent years, one such H5 lineage has become widely established in Asian domestic bird populations. Both H5 and H7 HPAI viruses have been sporadically transmitted to humans from domestic poultry, and (for H5 at least) been transmitted back into wild populations. However, because HPAI does not necessarily kill its anseriform hosts, reassortment with co-circulating LPAI viruses can occur, furthering evolution of the virus, while the low severity symptoms allow the long-range and intercontinental transport of the disease. ...

        https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6553608/

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