Tagged: bird flu
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- 9 December 2005 at 5:05 pm #3648Martin WilliamsKeymaster
Wild birds are not major carriers of H5N1 bird flu
here are some quotes from experts
David Melville (ornithologist) and K.F. Shortridge (virologist)Quote:the timing and distribution of the reported spread of H5N1 from South Korea (Dec 17, 2003) to Vietnam (Jan 8, 2004) to Indonesia (Feb 6, 2004) does not fit any known migratory pattern for any [waterbird] species
Influenza: time to come to grips with the avian dimension, The Lancet Vol 4, 2004.
Les Sims, veterinarian with extensive (unmatched?) experience with H5N1 in AsiaQuote:The situation remains that most of the spread of H5N1 HPAI has been associated with the poultry industry especially in places where the virus is endemic. Wild birds have almost certainly been involved in some of the long distance spread of virus recently (genetic evidence supports this as well), but that once established in a region, spread via poultry or items used with poultry will occur. Iif the disease is not rapidly controlled this becomes the main route of transmission.
(posted to this forum: thread on putting farming in the dock)
Hon S. Ip, United States Geological Survey, National Wildlife Health Center, Diagnostic Virology LaboratoryQuote:
Reports of the role of wild birds as the cause of new bird flu outbreaks occur almost daily, but at the present time, there is little evidence available to support such statements…
Movement of birds, including annual migration, is only one of several possible means of dissemination of the HPAI H5N1 virus. In many of the areas of recent outbreaks, there is a thriving trade of live birds and poultry products… Although much has been made of the recent pattern of spread as indicative of avian migration, many ornithologists have indicated that the spread of H5N1 does not fit with known behavior of the bird species in that area of the world (Butler, D. 2005. Nature: ): It should be noted that the same pattern of spread can just as easily be seen as from the major routes of human transportation.
posted on promed, 24 August 2005Quote:I think there is a lot of assumptions made out there that are not supported by the evidence.
email to me, 16 December 2005
Dr. David Swayne, director of the U.S. Department of Agriculture’s poultry research laboratory in Athens, GaQuote:They’re the sentinels. They’re not the reservoir that’s spreading it around. They’re infected because the poultry are infected… When you have an outbreak, sometimes you don’t really know what the cause was… Nobody going to be upset with you if you say wild birds.
In 5 Sept 2005 article by Helen Branswell, quoted in thread on this forum – don’t blame the birds. Swayne since come to believe wild birds behind spread to east Europe; tho don’t know he’ll remain fixed in this belief, given other info such as absence of spread in Asia.
Guan Yi, virologist, University of Hong KongQuote:
Governments embarassed by their failure to halt the flu’s spread welcome that idea [that H5N1 travelled in the guts of wild waterbirds]. “They get a free lunch,” says Guan Yi…
“Each time there’s an outbreak, they say, ‘It’s migratory birds. I cannot control them. I cannot lock my sky.” …
Guan isn’t ready to blame migratory birds for the spread so far. He thinks the virus has killed infected birds too quickly for them to fly long distances. Instead H5N1 probably hitchhiked across Asia in shipments of live poultry, in a disaster of our own making.
National Geographic October 2005.Quote:The outbreaks in China are not carried by the migratory birds… Bird flu has already taken root deeply in China [i.e. Chinese poultry]. Namely China itself is the source of bird flu.
– edited portion of Google translation from Epoch Times article on 30 November 2005, at http://www.epochtimes.jp/jp/2005/11/html/d56400.html – note that other recent articles on Guan Yi say his team has analysed over 100,000 samples from birds around China.
Moscow Zoo’s Chief Veterinarian (on Russian outbreaks) MOSCOW, October 27 (RIA Novosti, Maria Gusarova) – The Moscow Zoo’s Chief Veterinarian said Thursday that the cause of the bird flu outbreak is the unmonitored transit of domestic birds, not wild bird migration. “No one has proved anywhere that the carriers of avian flu are wild birds…
However, the black market for trading animals provides all the conditions for the unmonitored transit of un-examined birds,” Valentin Kozlitin said. http://en.rian.ru/russia/20051027/41911603.html
Professor Ron Ydenberg, heads the Center for Wildlife Ecology at Simon Fraser University in CanadaQuote:Wild birds are implicated spreading the disease because they travel a long distance. There is no absolute proof of that yet. The real issue is where the highly pathogenic strain of the virus comes from. That’s not in wild birds. It’s almost certain it comes from poultry population.
in Experts say flu fears over wild birds over-stated, 27 November 2005
Dr Michael Rands, director and chief executive of BirdLife InternationalQuote:The hypothesis that wild birds are to blame is simply far from proven. Wild birds occasionally come into contact with infected poultry and die: they are the victims not vectors of H5N1 bird flu.
Prof Diana Bell, a conservation biologist at the University of East Anglia, who studied the H5N1 strain back in 2007
//she has never heard of an asymptomatic bird with the virus and therefore doesn’t think wild birds would be able to spread it over long distances. She believes the international poultry trade is the main driver of the virus and says stopping imports of chicks and birds for the trade would be an important step in reducing the risk of future outbreaks. “Originally, it was poultry to wild birds; it was not wild birds which were spreading it. It was frustrating to see wild birds being blamed … We’ve got to get out of our heads that the wild birds are the bad guys here,”//
Attachments:20 February 2006 at 2:30 pm #3971Quote:
//”So far there is no evidence to link the migratory birds with present outbreak of bird-flu in Dhule-Nandurbar, as far we know,” said Dr Taej Mundkur, an ornithologist and a member of scientific task force on ‘Wild Birds and Avian Influenza’, set up by United Nations.
Moreover, he told PTI, “Migratory birds land in India much early, ie in September-October. So if they at all had carried the virus, it would have been noticed much earlier.” He added though, that “theoretically” all species of birds” can carry the virus responsible for bird flu.
He said that there are various ways in which the virus can spread, but most commonly it spreads through poultry-droppings.
Until now, he said, that movement of poultry and poultry products has been found to be most common cause of spread of virus across the world. “Illegal trafficking of pet or exotic birds is also one of the ways the virus can travel across,” he said.
Another reason, he said, could be illegally made substandard vaccines, which, instead of immunising, may infect the birds.//28 February 2006 at 4:29 pm #3972
"Migratory birds, scapegoats?" [French news article] A "machine translation":Quote:The role of the migratory birds would be completely "secondary" in the propagation of virus H5N1 of the influenza aviaire. It is at least in this direction that voices authorized in the ornithological medium rise. Principal argument: the migratory roads of the birds really do not stick with the countries or the zones touched by epizooty in the world. For Olivier Dehorter, ornithologist with the national Natural history museum of natural history, "there are great inconsistencies, leaving think that the virus does not travel inevitably with the migrating ones". Certain countries flown over by the migrating ones were not touched by epizooty. "the birds which left at the beginning of the winter Asia of north, passed to India and to Pakistan, but there was very little case of contamination in these two countries, explains Frederic Lamouroux, ornithologist with the park of the bridge of Gau, in the Camargue. Israel, toll of migrating towards the East Africa, was saved, like Australia, place of privileged wintering. Especially, the migratory increase of Africa towards Europe, by the axis Senegal-Mauritania-Morocco-Spain-Portugal, is not concerned. If the migrating ones were the vector of the H5N1, these countries should have been infested and to know a true hecatomb ". Until now, in Africa, the influenza aviaire was detected in Nigeria, and since yesterday, in close Niger. But, the ornithologists notice, it was to it four long months after the arrival of the birds on their places of wintering, and the virus struck domestic poultry breedings, located far from the wetlands sought by the migrating ones. "Since the beginning of epizooty, approximately 150 million domestic birds died in the world counters only 200 wild birds, and on the 2 000 declared hearths of contamination, a score has migrating implied in the perimeter", points out Pascal Orabi, of the League of protection of birds (LPO). Then, which is the culprit? For these specialists, it would be rather to seek side poultry world trade, legal or not.8 March 2006 at 11:40 am #3973Quote:Berlin – A German scientist said Tuesday the entry of faeces from infected poultry into the food chain via fish was a likely cause of the global spread of bird flu – and not migrating wild birds.
‘We are moving away from the assumption that migrating birds are the cause,’ said Josef H. Reichholf, a zoology professor at Munich’s Technical University, in a comment published by the newspaper Die Welt.
Reichholf said the spread of the virus from east to west did not follow the main routes of migratory birds and was also taking place at the wrong time of year.13 March 2006 at 10:30 pm #3974
“Migratory birds are probably the least likely way avian flu is going to enter the Western hemisphere,” says Peter Marra, a bird ecologist at the Smithsonian Institution in Washington, D.C.
The more likely route into the USA, he says, is through the pet trade and the movement of poultry, legally or illegally. “Migratory birds are innocent bystanders,” Marra says. “I don’t doubt (they’re) moving the virus. I just don’t think they’re the primary movers.”1 May 2006 at 11:00 pm #3975Anonymous
Greetings; hopefully those posting to this thread will be patient and help me frame some thoughts and questions concerning the avian bird flu matter. Can the actual research into the avian bird flu be a cause and effect device of man’s need to understand?
Consider, avian bird flu documented research can be traced back to the 1950’s, yet it never seems to make any headline news until 1997 when first reports of human fatalities began to surface. Looking at it from a basic mindset, science seems to use a test group in order to establish trends in a thing, taking the h5n1 virus and developing a test group in live poultry intergration farms can this be where it originates and if so can we find the proper antibodies needed to form a ‘cure’? My time is near up and yes there is a reasoning to my questions and would like to express them more as the next time allows. Thanks for listening and any answers to questions thus far to help inspire will be appreciated.
I wish you well.
Matthias24 January 2008 at 3:01 pm #3976
Quite a turnaround here for FAO, after chief vet Joseph Domenech so readily blamed wild birds for spreading H5N1:Quote:There is no solid evidence that wild birds are to blame for the apparent spread of the H5N1 virus from Asia to parts of Europe, Africa and the Middle East, an animal disease expert said on Wednesday.
There was also no proof that wild birds were a reservoir for the H5N1 virus, Scott Newman, international wildlife coordinator for avian influenza at the U.N.’s Food and Agriculture Organization, said at a bird flu conference in Bangkok.
“We know that some wild birds have probably moved short distances carrying viruses and then they died, but we have not been able to identify carriage of H5N1 across large scale spatial distances and then resulting in spread to other birds and mortality in poultry flocks,” Newman told Reuters.
He said fecal tests on some 350,000 healthy birds worldwide had to date only yielded “a few” positive H5N1 results.
Furthermore, in instances and places where wild birds were found with the disease, there were no concurrent outbreaks of the virus in poultry.
“So we don’t have at this point in time a wildlife reservoir for H5N1 … so they can’t be a main spreader of the disease,” Newman said.
He stressed the need to focus attention on the poultry trade, and particularly smuggling, adding that these factors may instead be spreading and sustaining the deadly disease.12 April 2010 at 6:45 am #4692
FAO has long vilified wild birds as major carriers of H5N1. Yet even FAO showing signs of relenting re this, with press release as follows [note that some years ago I showed outbreaks did not fit timings and routes of bird migrations in Asia: see Dead Ducks Don't Fly Yet, taken FAO years – and some fancy looking research – to catch up with this notion]:Quote:HPAI outbreaks along the East Asian flyway are related to latitude and poultry density, not to core migration corridor or wetland habitats
01 April 2010 – A recently published study that uses a newly developed Brownian bridge spatial analysis methodology found that highly pathogenic avian influenza (H5N1 HPAI) outbreaks reported along the East Asian flyway were related to latitude and poultry density but not to the core migration corridor or to wetland habitats used by migratory waterfowl. These findings suggest that there are temporal mismatches between the timing of reported outbreaks and wild duck movements.
Given that the Guangdong province in China has been pinpointed as the epicentre of H5N1 HPAI, it was deemed critical to better understand disease transmission dynamics between wild and domestic birds in this area. Poyang Lake is the largest freshwater body in China and it lies within the East Asian flyway. This lake is situated near Guangdong and represents a migratory corridor as well as a significant congregation site for waterfowl. Herein there are surrounding rice fields and free-grazing poultry flocks that interact with wild waterfowl, a situation that has been said to be largely conducive to avian influenza transmission across the poultry-wildlife sectors.
Scattered yet recurrent reports of H5N1 HPAI in healthy wild ducks at Poyang Lake, Qinghai Lake, and other locations globally, have raised concerns about the potential of resilient free-ranging wild birds to disseminate the virus over short and long distances. However, the lack of information about the migratory ecology of wild ducks has hindered understanding of the role these birds play in connecting regions that host and report H5N1 HPAI outbreaks throughout Asia.
In view of this information deficit, during 2007 and 2008, a group of research scientist from different countries mounted satellite transmitters on wild ducks at Poyang Lake to examine the location and timing of spring migration and to identify any spatiotemporal relationship with H5N1 HPAI outbreaks reported in this area.
The study included wild duck species such as the Eurasian wigeon (Anas penelope), the northern pintail (Anas acuta), the common teal (Anas crecca), the falcated teal (Anas falcata), the Baikal teal (Anas formosa), the garganey (Anas querquedula), the mallard duck (Anas platyrhynchos), and the Chinese spotbill (Anas poecilohyncha), a group of waterfowl that could play a role in transmission, based on their ability to serve, in general, as reservoirs of low pathogenic avian influenza viruses .
Satellite signal-based tracking maps indicate that these wild ducks [excluding the last two species] followed the East Asian flyway along the Chinese East coast to breeding areas in Northern China, Eastern Mongolia, and Eastern Russia yet none migrated West toward Qinghai Lake [the site of the largest wild bird epizootic], thus failing to demonstrate any relevant migratory connection to the Central Asian flyway.
Data analyses used novel approaches to integrate ecological information to better inform epidemiological investigations seeking to explain, predict and understand the spread of avian influenza viruses. The Emergency Centre for Transboundary Animal Diseases (ECTAD) at the UN Food and Agriculture Organization (FAO) will continue to actively collaborate with national governments, research centres, diagnostic laboratories, and universities to further elucidate the dynamic evolution of transboundary diseases in diverse ecological landscapes that include wildlife, livestock and people.11 December 2014 at 11:54 am #4927Quote:The numbers and density of modern poultry operations provide perfect conditions for the spread of viruses. Worst of all, they create opportunities for a low-pathogenic virus to become high-pathogenic, as a virus infecting a crowded barn of thousands of genetically identical birds has a greater chance to mutate into a more virulent form. As Earl Brown, a University of Ottawa microbiology professor specializing in flu virus evolution, has stated: “It is high-density chicken farming that gives rise to high-virulent influenza viruses.”6 February 2015 at 10:58 am #4930Anonymous
The wild bird route is promoted again, this article based on a Science paper is on the front page of BBC news:
But reading it there is no actual evidence, just speculation; in particular someone ought to be asked to explain the arrow from Russia to sub-Saharan Africa – which species of wildfowl follow this route? Of course there are none…
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