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Flu Resistant Poultry (Revisited)

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  • Flu Resistant Poultry (Revisited)

    Flu Resistant Poultry (Revisited)

    #13,610

    Between a steadily rising global population, increasingly erratic climatic conditions, and the constant thrat of epizootic and other agricultural diseases, there are genuine concerns on how we feed an increasingly hungry planet going forward.

    The FAO's report The State of Food Security and Nutrition in the World 2017 shows a sharp rise in food insecurity around the world since 2014 (see chart below), and warns: AFTER A PROLONGED DECLINE, WORLD HUNGER APPEARS TO BE ON THE RISE AGAIN.





    Avian influenza has long been known to circulate in wild aquatic birds of the orders Anseriformes (ducks, geese, and swans, etc.) and Charadriiformes (shorebirds, gulls, and auks, etc.) - and importantly - these species can often carry these viruses will little or no ill effect.

    Less well adapted to the viruses, and therefore far more susceptible to illness, are the Galliformes; an order of heavy-bodied ground-feeding birds that includes turkey, chicken, quail and pheasant.
    Commercially raised gallinaceous birds are easily infected by both low and high path viruses, and can rapidly succumb to HPAI infection.
    Over the past several decades we've seen massive losses in the poultry sector due to an array of (mostly) H5 and H7 HPAI viruses, causing not only severe economic losses, but also increases in food insecurity around the world (see Iran: Bird Flu, Food Insecurity & Civil Unrest).

    For the past 20 years, serious consideration has been given to developing - either through selective breeding or genetic modification - a flu resistant chicken, in the hopes that it would reduce not only the risk to the poultry sector, but might also diminish the chances of seeing an avian flu pandemic.

    Six years ago, in CSIRO: The Quest For Flu Resistant Poultry,we looked at the progress made in this endeavor by Australia's national science agency CSIRO (Commonwealth Scientific and Industrial Research Organisation).
    One of those projects involved CSIRO research scientist, Dr Tim Doran, who was using a technique called gene silencing to “switch off” genes that make chickens susceptible to HPAI H5 viruses (see Silencing the bird flu gene: scientists prep live hen trials).
    Dr. Doren is back today, along with other researchers from Australia and the Netherlands, with a review of the options for creating flu resistant poultry, the progress to date, and the challenges that still lie ahead in the following review article from the journal Viruses.

    I've only included a couple of small excerpts, so you'll want to follow the link to read it in its entirety. When you return, I'll have a postscript.
    Fong Yang Looi 1, Michelle L. Baker 2, Thomas Townson 1, Mathilde Richard 3, Ben Novak 2, Tim J. Doran 2 and Kirsty R. Short 1,4,*


    Received: 27 September 2018 / Accepted: 12 October 2018 / Published: 15 October 2018

    Abstract:
    Influenza A virus (IAV) represents an ongoing threat to human and animal health worldwide. The generation of IAV-resistant chickens through genetic modification and/or selective breeding may help prevent viral spread. The feasibility of creating genetically modified birds has already been demonstrated with the insertion of transgenes that target IAV into the genomes of chickens. This approach has been met with some success in minimising the spread of IAV but has limitations in terms of its ability to prevent the emergence of disease.
    An alternate approach is the use of genetic engineering to improve host resistance by targeting the antiviral immune responses of poultry to IAV. Harnessing such resistance mechanisms in a “genetic restoration” approach may hold the greatest promise yet for generating disease resistant chickens. Continuing to identify genes associated with natural resistance in poultry provides the opportunity to identify new targets for genetic modification and/or selective breeding.
    However, as with any new technology, economic, societal, and legislative barriers will need to be overcome before we are likely to see commercialisation of genetically modified birds.

    (SNIP)
    8. Conclusions

    The recent outbreaks of H5Nx viruses across the world highlight the continual threat that avian influenza viruses pose to both poultry and human health. Rapid advances in genomics and gene editing suggest that disease resistant, genetically modified chickens could represent a viable solution to the problem of avian influenza.
    However, whilst the creation of influenza resistant chickens is technically possible, there still remain many barriers in place blocking their commercial implementation. These include issues such as consumer concerns and a detailed assessment of their commercial and environmental viability.
    It is possible some of these issues can be circumvented and/or mitigated with alternative approaches such as selective breeding and/or genetic restoration. However, regardless of the methodology used, novel approaches to address the issue of avian influenza must remain a global health priority.
    Over the years we've looked at the relative susceptibility of different bird species to Highly Pathogenic Avian Influenza, including.As a general rule, waterfowl are the most resistant to infection and/or illness - poultry are the most susceptible - and passerine species (perching birds) fall somewhere in between.

    However, when the H5N8 virus sparked Europe's largest epizootic over the winter of 2016/17, it exhibited a number of genetic and behavioral changes following a reassortment that took place sometime in the spring of 2016 (see EID Journal: Reassorted HPAI H5N8 Clade 2.3.4.4. - Germany 2016).
    Among the changes, this reinvented HPAI H5 virus displayed rapid geographic spread (including to Africa & the Middle East), increased virulence and mortality in wild birds (including waterfowl), and a greatly expanded avian host range.
    Finding ways to make farm animals more disease resistant - particularly without feeding them a constant diet of antibiotics and antivirals - is an incredibly important goal, and worthy of pursuit.
    But flu viruses have continually demonstrated an ability to evolve, adapt, and overcome when confronted by barriers like vaccines and antivirals. And recently, we can add HPAI H5's recent persistence and increased pathogenicity in waterfowl.
    Assuming the substantial challenges of creating a `flu-resistant' chicken can be met - either through genetic modification or selective breeding - and that it is broadly accepted by both the public and the poultry industry, the obvious concern will be just how permanent of a solution this actually turns out to be.

    And that is something I don't expect we can really know until we try.

    http://afludiary.blogspot.com/2018/1...-revisted.html

    All medical discussions are for educational purposes. I am not a doctor, just a retired paramedic. Nothing I post should be construed as specific medical advice. If you have a medical problem, see your physician.

  • #2
    merci,

    en terme de management, ce qui est important c'est de d?finir le sens. Mais, cela va mieux, si le sens, ou la direction est partag?e , par plus d'un, d'ou cet ?change ...



    Je fais partie de ceux qui savent que c'est la vaccination du sauvage contre la rage qui a ?t? la vraie bonne solution. Mais, on n'a pas commenc? par cela ... De m?me, ce sera, la vaccination du sauvage contre la peste porcine africaine, dans certaines zones et ? certains moments, qui sera la seule vraie solution...



    D?finir une direction partag?e , cela pourrait faire outre beaucoup de bien, permettre de tr?s s?rieuses ?conomies, de mon point de vue...


    Vous ?tes am?ricain, alors, pourquoi ne pas commencer par les influenzas et la dinde ?


    J'aimerai bien lire, le su concernant ce volatile symbole aux Etats Unis . Par exemple, vous, qui osez chercher , vous en avez isol? combien de souches d'influenzas sur les populations de dindes sauvages am?ricaines ?

    il me semble que le nombre est au moins ? quatre chiffres, alors qu'officiellement, il n'y a rien , non ?


    The species Meleagris gallopavo is used by humans for their meat. They were first domesticated by the indigenous people of Mexico from at least 800 BC onwards. These domesticates were then either introduced into what is now the US Southwest or independently domesticated a second time by the indigenous people of that region by 200 BC, at first being used for their feathers, which were used in ceremonies and to make robes and blankets.[20] Turkeys were first used for meat by Native Americans by about AD 1100.[20] Compared to wild turkeys, domestic turkeys are selectively bred to grow larger in size for their meat.[21][22] Americans often eat turkey on special occasions such as at Thanksgiving or Christmas.[23][24]

    https://en.wikipedia.org/wiki/Turkey_(bird)


    Pour ?tre complet, je vous demande de regarder le dossier dinde , qui ne produit que de la viande, car, concernant les poules, ce qui a fait que des d?cisions de gestion ont ?t? prises, ce me semble car les oeufs de poules , cela a servi et sers encore , pour partie, ? faire des vaccins ? destination, aussi humaine... Donc, les mesures drastiques prises ont ?t? pour l'Homme , pas, pour la Vie ...

    Une direction qui respecte la Vie, cela a plus de chance d'?tre partag?e ...


    Vous mettez en lumi?re le CSIRO, ce me semble des personnes qui se permettent d'user de moyens biologiques pour, soit disant, la maitrise du vivant, et cela s'?chappe toujours, avec plus ou moins un peu d'aide , d'ailleurs, c'est normal ?



    Ce genre de pratique n'a aucune chance d'?tre officiellement partag?e. Certains souhaitent m?me de tr?s importantes sanctions, notamment, ?conomiques...


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    • #3
      pour ?clairer mon interrogation :

      Suite au foyer d?influenza aviaire hautement pathog?ne de 2015 survenu au c?ur du Minnesota, une surveillance renforc?e a ?t? mise en ?uvre pour les mois de printemps et d?automne. Cette surveillance de routine a permis de d?tecter le virus H5N2 de l?influenza aviaire faiblement pathog?ne (LPAI) dans un troupeau de dindes de chair d?une exploitation commerciale. Le troupeau ?tait bien portant et ne pr?sentait pas de signes cliniques de l?influenza aviaire. Le s?quen?age partiel de HA/NA a d?termin? que H5 et N2 ?taient un virus faiblement pathog?ne de la lign?e des oiseaux sauvages nord-am?ricains. Les r?sultats de l?isolement viral permettront une caract?risation plus pouss?e.
      Le Bureau v?t?rinaire (BAH) du Minnesota ainsi que les Services d?inspection v?t?rinaire et phytosanitaire (APHIS) de l?USDA m?nent une enqu?te ?pid?miologique sur cet ?v?nement et ont intensifi? la surveillance dans la zone suite ? cette d?tection. Des agents officiels ont mis les ?levages atteints en quarantaine et ont mis en ?uvre des contr?les de mouvements. Les dindes de ces ?levages seront abattues et mises sur le march? de fa?on contr?l?e.


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