Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

[Shiloh]

Source: http://elitestv.com/pub/2009/05/mig...ic-avian-influenza-h5n1-virus-in-eastern-asia

Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia
By PLoS ONE ? on May 28, 2009


Evaluating the potential involvement of wild avifauna in the emergence of highly pathogenic avian influenza H5N1 (hereafter H5N1) requires detailed analyses of temporal and spatial relationships between wild bird movements and disease emergence. The death of wild swans (Cygnus spp.) has been the first indicator of the presence of H5N1 in various Asian and European countries; however their role in the geographic spread of the disease remains poorly understood. We marked 10 whooper swans (Cygnus cygnus) with GPS transmitters in northeastern Mongolia during autumn 2006 and tracked their migratory movements in relation to H5N1 outbreaks. The prevalence of H5N1 outbreaks among poultry in eastern Asia during 2003?2007 peaked during winter, concurrent with whooper swan movements into regions of high poultry density. However outbreaks involving poultry were detected year round, indicating disease perpetuation independent of migratory waterbird presence. In contrast, H5N1 outbreaks involving whooper swans, as well as other migratory waterbirds that succumbed to the disease in eastern Asia, tended to occur during seasons (late spring and summer) and in habitats (areas of natural vegetation) where their potential for contact with poultry is very low to nonexistent. Given what is known about the susceptibility of swans to H5N1, and on the basis of the chronology and rates of whooper swan migration movements, we conclude that although there is broad spatial overlap between whooper swan distributions and H5N1 outbreak locations in eastern Asia, the likelihood of direct transmission between these groups is extremely low. Thus, our data support the hypothesis that swans are best viewed as sentinel species, and moreover, that in eastern Asia, it is most likely that their infections occurred through contact with asymptomatic migratory hosts (e.g., wild ducks) at or near their breeding grounds.

For the full article visit: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

Syndicated from:PLoS ONE

 

[HenryN]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

The above paper fails to look at sequences. It is just another propaganda piece.

 

[mixin]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

PLoS ONE will rigorously peer-review your submissions and publish all papers that are judged to be technically sound.

Does propaganda qualify as being technically sound?

The study comes with 34 referenced papers, for anyone who is interested.

 

[gsgs]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

so, that large H5N1-outbreak (Qinghai strain) in 2007 or 2008 in
South-Korea, which then went to Japan
and which strikingly coincided with the satellite-paths
(Mongolia-->South Korea)- that was just coincidence ?

It must be somewhere in the paper, but hard to find...

 

[mixin]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

firgure 3 is a map of the Whooper movements, outbreak locations, etc.

This paper only discusses Whooper swans; we still have all the other types of migratory and wild birds to blame.

 

[HenryN]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

firgure 3 is a map of the Whooper movements, outbreak locations, etc.

This paper only discusses Whooper swans; we still have all the other types of migratory and wild birds to blame.

Whooper swans and H5N1 (clade 2.2 Uvs Lake) flew from Mongolia to South Korea / Japan at the end of 2006/2007. They also were infected with Fujian H5N1 in the spring of 2008 (and dead in Japan).

The report is conceptually flawed, and just more propaganda from the same groups that couldn't find Qinghai H5N1 in live waterfowl in Mongolia in the summer of 2005, when this issue wild bird transport and transmission of H5N1 was settled.

 

[mixin]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

The report is conceptually flawed, and just more propaganda ...

Then I don't understand the concept of peer review. I thought the paper was read and judged by people who know these things.

So now do I add PloS to my list of sites who (according to you) publish propaganda?

 

[gsgs]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

do they mention this outbreak ?
I think it was the first outbreak after 2003 or 2004
and first introduction of H5N1 into Korea.

Subsequently it may have further spread by poultry trade
or other birds, but the introduction coincided
with the swan migration maps, AFAIR

 

[canagica]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

Whooper swans and H5N1 (clade 2.2 Uvs Lake) flew from Mongolia to South Korea / Japan at the end of 2006/2007. They also were infected with Fujian H5N1 in the spring of 2008 (and dead in Japan).

The report is conceptually flawed, and just more propaganda from the same groups that couldn't find Qinghai H5N1 in live waterfowl in Mongolia in the summer of 2005, when this issue wild bird transport and transmission of H5N1 was settled.

I'd love to see the reference for the H5N1-infected whooper swan migration from Mongolia to South Korea/Japan! It would definitely help in teasing apart some of the complexity of the epidemiological trail of H5N1 (as I understand it, the sequences suggest that the same strain of H5N1 was in both places, but not too much about how it got there). But until that paper exists, I think it would be prudent to look at your unsupported accusations to better understand your position...

You write: "The report is conceptually flawed..." "...more propaganda..."Might be useful to include a little more info about why if you're going to be taken seriously! (I've gotta agree with Mixin on that one)

In a nutshell, as I understand it, the concept behind the PLoS1 paper is that swans tend to die quickly when infected with HPAI H5N1, and that there is some support for migratory performance being impaired while infected based upon another study of LPAI in whoopers. These two facts suggest that swans probably aren't that efficient a dispersal agent for H5N1. That really doesn't seem like a huge leap in logic, and is far from propaganda territory. They actually reference a few things to support their assertions, rather than spouting off.

So-if swans are getting infected from poultry, then you would expect them to die near poultry. If they're getting infected from some other agent, you would expect it to be elsewhere. These authors, after looking at the timing of whooper migration, the timing of waterfowl migration, stopover/breeding/wintering habitats, waterfowl populations, etc., found that the most parsimonious rationale for swan die-offs probably involved asymptomatic wild ducks (due to a number of reasons). They talk about a variety of other explanations in the discussion, but they do a little homework and instead of simply waving their hands they explain how their conclusions follow the sum of what is known, including the disclaimer that there is very limited knowledge.

How again is this propaganda? By your litmus test (not using sequences = propaganda) most of what is published would be propaganda. It would be helpful if you could spend a little more time with your forum posts so that someone might be able to understand your position--IMHO you do yourself an extreme disservice to your position as a scientist and a person to take seriously in the ongoing challenge of understanding the epidemiology of H5N1 by simply parroting "propaganda". I also find it seriously disrespectful of all of the hard work that goes into each study.

But in the end, the continuing cry of "propaganda" is always good for a laugh! To think, that these scientists have nothing better to do than to cook up a global conspiracy on the wages they get paid...

 

[HenryN]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

I'd love to see the reference for the H5N1-infected whooper swan migration from Mongolia to South Korea/Japan! It would definitely help in teasing apart some of the complexity of the epidemiological trail of H5N1 (as I understand it, the sequences suggest that the same strain of H5N1 was in both places, but not too much about how it got there). But until that paper exists, I think it would be prudent to look at your unsupported accusations to better understand your position...

You write: "The report is conceptually flawed..." "...more propaganda..."Might be useful to include a little more info about why if you're going to be taken seriously! (I've gotta agree with Mixin on that one)

In a nutshell, as I understand it, the concept behind the PLoS1 paper is that swans tend to die quickly when infected with HPAI H5N1, and that there is some support for migratory performance being impaired while infected based upon another study of LPAI in whoopers. These two facts suggest that swans probably aren't that efficient a dispersal agent for H5N1. That really doesn't seem like a huge leap in logic, and is far from propaganda territory. They actually reference a few things to support their assertions, rather than spouting off.

So-if swans are getting infected from poultry, then you would expect them to die near poultry. If they're getting infected from some other agent, you would expect it to be elsewhere. These authors, after looking at the timing of whooper migration, the timing of waterfowl migration, stopover/breeding/wintering habitats, waterfowl populations, etc., found that the most parsimonious rationale for swan die-offs probably involved asymptomatic wild ducks (due to a number of reasons). They talk about a variety of other explanations in the discussion, but they do a little homework and instead of simply waving their hands they explain how their conclusions follow the sum of what is known, including the disclaimer that there is very limited knowledge.

How again is this propaganda? By your litmus test (not using sequences = propaganda) most of what is published would be propaganda. It would be helpful if you could spend a little more time with your forum posts so that someone might be able to understand your position--IMHO you do yourself an extreme disservice to your position as a scientist and a person to take seriously in the ongoing challenge of understanding the epidemiology of H5N1 by simply parroting "propaganda". I also find it seriously disrespectful of all of the hard work that goes into each study.

But in the end, the continuing cry of "propaganda" is always good for a laugh! To think, that these scientists have nothing better to do than to cook up a global conspiracy on the wages they get paid...

The nonsense has been posted since 2005, and explanations have been made dozens of times. Similarly, the satellite maps of swans flying between Mongolia and South Korea have also been posted multiple times.
The hard work has earned the propaganda label many times over.

The reason this nonsense is so annoying, is because after the reasons have been given, the same utter nonsense is repeated along with "requests" for the SAME explanations.

The issue was settled in the summer of 2005, and remains unchanged, regardless of how many nonsense posts and publications follow.

 

[canagica]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

The nonsense has been posted since 2005, and expalinations have been made dozens of times. Similarly, the satellite maps of swans flying between Mongolia and South Korea have also been posted multiple times.
The hard work has earned the propaganda label many times over.

The reason this nonsense is so annoying, is because after the reasons have been given, the same utter nonsense is repeated along with "requests" for the SAME explanations.

The issue was settled in the summer of 2005, and remains unchanged, regardless of how many nonsense posts and publications follow.

I guess you missed my point. It would be helpful to know why you think this particular study is propaganda? Is it their assumptions on how effective a vector whooper swans would be? Is it their assumption that asymptomatic waterfowl probably play a major role in spreading H5N1? What, exactly, makes it nonsense?

If the issue was truly settled in 2005, please give us an idea of the references that so clearly delineate it so we can read the data ourselves. My bet is that the understanding of H5N1 transmission is not so clear as you suggest, hence the still foggy publications that hit the journals, years after the first outbreak...

 

[HenryN]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

I guess you missed my point. It would be helpful to know why you think this particular study is propaganda? Is it their assumptions on how effective a vector whooper swans would be? Is it their assumption that asymptomatic waterfowl probably play a major role in spreading H5N1? What, exactly, makes it nonsense?

If the issue was truly settled in 2005, please give us an idea of the references that so clearly delineate it so we can read the data ourselves. My bet is that the understanding of H5N1 transmission is not so clear as you suggest, hence the still foggy publications that hit the journals, years after the first outbreak...

This is well into the "if you don't get it by now, you never will category". The role of long range migartory birds in the transmission and transport of H5N1 was definitively established in 2005 after the Qinghai (clade 2.2) outbreak at Qinghai Lake was followed by the same clade infecting birds and people in 50 countries west of China (in Europe, the Middle East, and Aftica) in the following 12 months. ALL infections (in humans, poultry, and wild birds were clade 2.2 which had NEVER been previously reported in ANY of the 50 countries.

This has been described dozens of times.

The data could not be clearer and if you still think this issue is unsettled......

The role of conservation groups and the propaganda campaign denying the obvious has also been dicussed dozens of times.

 

[mixin]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

The data could not be clearer and if you still think this issue is unsettled......

The role of conservation groups and the propaganda campaign denying the obvious has also been dicussed dozens of times.

I'm just curious...

Do you ever read the migratory bird studies or do you automatically designate them as propaganda?

 

[canagica]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

This is well into the "if you don't get it by now, you never will category". The role of long range migartory birds in the transmission and transport of H5N1 was definitively established in 2005 after the Qinghai (clade 2.2) outbreak at Qinghai Lake was followed by the same clade infecting birds and people in 50 countries west of China (in Europe, the Middle East, and Aftica) in the following 12 months. ALL infections (in humans, poultry, and wild birds were clade 2.2 which had NEVER been previously reported in ANY of the 50 countries.

This has been described dozens of times.

The data could not be clearer and if you still think this issue is unsettled......

The role of conservation groups and the propaganda campaign denying the obvious has also been dicussed dozens of times.

So-how does what you just wrote differ from what the authors in the paper wrote? I was looking for a while in the paper and couldn't find a spot where they said (or even really intimated) that migratory birds don't play a role in spreading H5N1. If I remember correctly, the paper was about swans. They are ONE kind of migrating bird. Believe it or not, but there are others: Ducks and geese, songbirds and seabirds...They do different things, migrate in different ways, eat and behave differently...

And the assumption they were working under is that maybe, just maybe, if you look at all of the epidemiological evidence that has been uncovered, swans don't look like they'd be a very efficient vector. Oh sure, they're good at dying from H5N1, but the data we DO have suggest that they would be one of the least likely long-distance vectors of H5N1. But of course, I could be part of the well-financed, highly-organized left-wing conservation agenda. You never know...

I don't mean this in a disrespectful way, but did you actually read the paper? I think it's a fair question to ask, because your rationale for proclaiming it propaganda

...The role of long range migartory birds in the transmission and transport of H5N1 was definitively established in 2005 after the Qinghai (clade 2.2) outbreak at Qinghai Lake...

is actually supported by this paper...I mean, SHEESH, the last sentence in their abstract says

in eastern Asia, it is most likely that their infections occurred through contact with asymptomatic migratory hosts (e.g., wild ducks) at or near their breeding grounds.

Wild ducks = long range migratory birds. Sequences can tell us a lot of things, but AFAIK, so far we can't tell who the primary players are in long-distance transmission via wild birds. There's a consensus that wild birds vary in their susceptibility to HPAI H5N1, as well as variation in the duration of asymptomatic infection; but I can't think of any comprehensive study (or even sets of studies) that has clearly delineated the variation such that we have a good grasp of which species/places/climate/etc. are the most important vectors across any geographic scale.

I'm not trying to play "gotcha" here; I simply think that it's irresponsible for a well-known scientist to not pay attention to all of the data, because people trust your position...It just downplays the value of research (any research!) in favor of talking-head opining, and erodes the public trust in science.

If there is a big problem that you see :magnify: with this paper, I'd sincerely be interested in hearing it, as I manage a stream of AI-related information to a group of avian scientists here stateside, communicating information and analysis of publications that involve wild birds. These forums are one of the most fruitful places to discuss these issues with a wide variety of voices, and I appreciate the time and effort that most people put into their posts...

 

[HenryN]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

So-how does what you just wrote differ from what the authors in the paper wrote? I was looking for a while in the paper and couldn't find a spot where they said (or even really intimated) that migratory birds don't play a role in spreading H5N1. If I remember correctly, the paper was about swans. They are ONE kind of migrating bird. Believe it or not, but there are others: Ducks and geese, songbirds and seabirds...They do different things, migrate in different ways, eat and behave differently...

And the assumption they were working under is that maybe, just maybe, if you look at all of the epidemiological evidence that has been uncovered, swans don't look like they'd be a very efficient vector. Oh sure, they're good at dying from H5N1, but the data we DO have suggest that they would be one of the least likely long-distance vectors of H5N1. But of course, I could be part of the well-financed, highly-organized left-wing conservation agenda. You never know...

I don't mean this in a disrespectful way, but did you actually read the paper? I think it's a fair question to ask, because your rationale for proclaiming it propaganda

is actually supported by this paper...I mean, SHEESH, the last sentence in their abstract says Wild ducks = long range migratory birds. Sequences can tell us a lot of things, but AFAIK, so far we can't tell who the primary players are in long-distance transmission via wild birds. There's a consensus that wild birds vary in their susceptibility to HPAI H5N1, as well as variation in the duration of asymptomatic infection; but I can't think of any comprehensive study (or even sets of studies) that has clearly delineated the variation such that we have a good grasp of which species/places/climate/etc. are the most important vectors across any geographic scale.

I'm not trying to play "gotcha" here; I simply think that it's irresponsible for a well-known scientist to not pay attention to all of the data, because people trust your position...It just downplays the value of research (any research!) in favor of talking-head opining, and erodes the public trust in science.

If there is a big problem that you see :magnify: with this paper, I'd sincerely be interested in hearing it, as I manage a stream of AI-related information to a group of avian scientists here stateside, communicating information and analysis of publications that involve wild birds. These forums are one of the most fruitful places to discuss these issues with a wide variety of voices, and I appreciate the time and effort that most people put into their posts...

Please. The tracking of Whooper Swans from Mongolia to South Korea EXACTLY matches the outbreak at the end of 2006 (and feces at locations frequented by migratory birds was Evs Lake clade 2.2). This was noted in Commentaries in 2006.

Qinghai H5N1 Confirmed On South Korean Farms
Recombinomics Commentary
December 15, 2006

South Korea confirmed a highly pathogenic bird flu outbreak on Nov. 25 at a poultry farm in Iksan, about 230 kilometers south of Seoul, the country's first case in three years. Two additional cases of highly virulent avian influenza were discovered Nov. 27 and earlier this week, respectively, in nearby poultry farms.

Genetic analysis of the N5H1 virus sample specimens from the first two cases showed traits similar to ones found in China's midwestern province of Qinghai.

<snip>

The transmission routes are now reinforced by the discover of the Qinghai strain in South Korea. H5N1 has been found in whooper swans in Mongolia, and tracking data shows movement of whooper swans from Mongolia to the precise location on the western South Korean coast, where the recent H5N1 infections were reported. These swans have since migrated to the eastern coast of Korea, and infections in Japan in the upcoming weeks would not be a surprise. This time line and location match the 2003 outbreak in December 2003 in South Korea and predict early 2007 outbreaks in Japan...................

 

[AlaskaDenise]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

...but there are others: Ducks and geese, songbirds and seabirds...They do different things, migrate in different ways, eat and behave differently...

I've long assumed that much AI transmission wasn't always directly from one species, but rather like the passing of a baton in a relay race. (Dr. Niman's analogy) Even if one species didn't get infected in their breeding area (which is likely as they don't always "mix" much while breeding), their travel companions might be asymptomatic carriers and would pass it to another species (including local wild birds) during a several-day food/rest stop.

I remember when H5N1 first came to Turkey in 2005/2006. It arrived in some migratory birds that died at a reservoir, then about 3 weeks later local wild birds started dying, then another 3 weeks later local poultry started dying, and about 3 weeks later people started dying. I think it takes some time for an infection to spread enough that there is a higher density of ill birds, thereby creating the circumstances for likely spread to other hosts.

If those Whooper Swans are like our local Trumpeter Swans, they claim a lake as their exclusive territory during breeding. Other swans might make quick stops during migration, but once breeding has started an established pair will attack other swans. However, during migration they share lakes/ponds/wetlands with other swans and a wide variety of other species. That mix of species can vary during their migration, as there are major "funnels" where there may be a one time mixing with another species.

Given all the variables in migratory patterns, etc. I'd consider the conclusions from a single-species study to be less reliable than one from a multi-species study.

.

 

[canagica]

Re: Migration of Whooper Swans and Outbreaks of Highly Pathogenic Avian Influenza H5N1 Virus in Eastern Asia

I've long assumed that much AI transmission wasn't always directly from one species, but rather like the passing of a baton in a relay race. (Dr. Niman's analogy) Even if one species didn't get infected in their breeding area (which is likely as they don't always "mix" much while breeding), their travel companions might be asymptomatic carriers and would pass it to another species (including local wild birds) during a several-day food/rest stop.

I remember when H5N1 first came to Turkey in 2005/2006. It arrived in some migratory birds that died at a reservoir, then about 3 weeks later local wild birds started dying, then another 3 weeks later local poultry started dying, and about 3 weeks later people started dying. I think it takes some time for an infection to spread enough that there is a higher density of ill birds, thereby creating the circumstances for likely spread to other hosts.

If those Whooper Swans are like our local Trumpeter Swans, they claim a lake as their exclusive territory during breeding. Other swans might make quick stops during migration, but once breeding has started an established pair will attack other swans. However, during migration they share lakes/ponds/wetlands with other swans and a wide variety of other species. That mix of species can vary during their migration, as there are major "funnels" where there may be a one time mixing with another species.

Given all the variables in migratory patterns, etc. I'd consider the conclusions from a single-species study to be less reliable than one from a multi-species study.

.

I totally agree with you-that's what I think makes this study interesting. They're basically suggesting that swans are less likely to be involved in long-distance transmission, but that other species are more likely to be the long-distance vectors.

It would be useful to know which other species are migrating just before/during/after the swans, and to see what the rate of disease transmission is locally from infected swans. For example, perhaps they don't play a huge role in long-distance transmission (as this study suggests), but maybe they are highly contagious once infected, and are actually a very important link in maintaining infection rates across multiple species during migration.

Dr. Niman brings up the point that outbreaks coincides with arrival of migrating whoopers; nothing he cites precludes the equally likely scenario of them becoming infected upon arrival through contact with other infected species. Which other species were there when they arrived? How long had they been there? What is the phenology of species migrating through Asia? We know very little about these questions, and to say that because the distribution of infected whoopers overlaps with the timing of outbreaks misses the point! It might also correlate well with sunspot activity, etc. Correlation doesn't prove anything--which is why it's important to try to get to the bottom of how H5N1 travels through the environment, where the reservoirs are, how efficiently it's transmitted between species, what the proportion of asymptomatic carriers are, and then overlay that onto breeding/migration phenology, poultry production, climate.

It's a much more complex equation that would actually give us some ability to predict where outbreaks might arise, prioritize limited resources for biosecurity & wetlands conservation, and to enact preventative measures to help local populations weather the storm...