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28 January 2006 at 11:48 am #3290
New Scientist writer Deborah MacKenzie just blaming wild birds for spreading H5N1 to Europe, based on flimsy “evidence” (and fair dollop of Nimanism?):Quote:HAS the H5N1 bird flu virus crossed Asia on the wings of migrating wild birds? Yes, say governments and UN agencies. Prove it, say many bird
conservationists, who fear we are about to see an irresponsible and
unjustified cull. “People have just accepted that migrant birds are
carrying disease,” charges Richard Thomas of Bird Life International in
What is beyond dispute is that in May 2005, thousands of wild geese died
of H5N1 at Qinghai Lake in China. A smaller outbreak in migrant geese
and swans followed in Mongolia. Then in late July the disease cropped up
in poultry near Novosibirsk in Siberia, before moving west to five more
regions in Russia and to Kazakhstan by August, Romania and Turkey in
October, and Ukraine in December.
Conservationists point out that these outbreaks are clustered along
major long-distance transport routes. They say this shows that
commercial poultry, not migrating wild birds, are the vectors of the
infection. Virologists, however, tell a different story.
Aside from a single test on a grebe in Novosibirsk, no one has yet found
a smoking gun: healthy migrant birds carrying H5N1. But we do know that
H5N1 can be carried and spread by healthy domestic ducks, and therefore
probably by wild ducks – experiments are under way to find out. Moreover
there is circumstantial evidence that the outbreaks are consistent with
Ward Hagemeijer of the conservation group Wetlands International
concludes that the best explanation for the outbreak of H5N1 in Mongolia
is that it was carried by infected migrating birds heading north from
Qinghai. The further outbreaks can be explained by birds flying from
Qinghai to north Siberian nesting grounds, where they mingled with, and
perhaps infected, ducks from wintering grounds across the breadth of
Asia and Europe, including the Black Sea coast and south Siberia. Birds
that failed to mate, says Hagemeijer, then headed south in July – just
in time for the outbreaks in south Siberia and Kazakhstan. The Black Sea
outbreaks followed the main migration in autumn.
Genetic studies support this idea. Every outbreak in east Asia tested
since 2004 was caused by a strain of H5N1 known as the “Z genotype”. But birds in Qinghai, and in outbreaks to the west, were infected by a
slightly different strain, a hybrid of the Z genotype with its immediate
ancestor. The virus in both wild and domestic birds across Russia was
closely related to the Qinghai virus, while swans in Romania died from a
virus most closely related to the one in the grebe in Novosibirsk.
If the disease was being transmitted through poultry carried out of
China, then at least some of the western outbreaks should be the Z
genotype that has dominated outbreaks in China. But not one bird in west
Asia or Europe has been found with this strain. “We haven’t sequenced
everything,” cautions Juan Lubroth of the UN Food and Agriculture
Organization in Rome, Italy. “But the pattern does suggest that wild
birds are introducing the virus to new areas.”
That doesn’t mean the answer lies in the wholesale slaughter of wild
birds -which is conservationists’ worst fear. The real problem for
people is not the wild birds, but infected poultry. It has been obvious,
everywhere the virus has been, that poor management of domestic flocks
is what transmits the infection throughout a region once it has arrived.
And people have overwhelmingly caught the virus from their backyard
chickens not from passing wild ducks.
“What can we do about the wild birds? Nothing,” says Lubroth – shooting
them just scatters them, and anything they may be carrying. “What can we do about poultry? A lot.”
As I’ve just emailed a group of people interested in H5N1 and conservation:
I think Henry Niman indeed has role here; recall seeing something in New Sci (lighter side), re them having earlier done piece noting all wild birds with H5N1 sick/ding, and Niman wrote to pillory them, mentioning this grebe.
Indeed ridiculous to build case for spread by wild birds on one purportedly healthy bird, with no further info (All seen earlier was a report saying a GCG “showing no clinical symptoms” had been found with H5N1. It gave no details about whether the bird was even dead or alive, nor whether it was HPAI H5N1. Maybe, like four birds in OIE report re Russia, it was hunted, say).
Likewise this assertion that should see more variety in H5N1 clades reaching eastern Europe seems highly dubious. There are huge holes in our knowledge, inc for nw China; Guan Yi – who unlike Niman, does massive testing, saying wild birds not to blame.
But, Niman is indeed King of the Ridiculous; and here has found another willing messenger. (cf Stratis Times guy earlier, doing big piece about H5N1 and Ebola perhaps mixing in Sichuan: neither were present, but still, Niman found another to spread his nonsense)
Bizarre, too, to ignore facts that birds infected in eastern Europe not originating in areas known to have H5N1.
Also re 75,000 – 100,000 other healthy birds tested, all H5N1 negative.
And bizarre to ignore current lack of H5N1 in Asian waterfowl in Asia (ex-Russia). How can they spread to Europe when can’t spread round Asia?
– we have perhaps a hundred Great Crested Grebes wintering in Hong Kong’s Deep Bay, yet no H5N1 evident there (and, happily, nothing further re H5N1 here since the recent magpie robin)
Who on earth is “Ward Hagemeijer of the conservation group Wetlands International”? Believe guy of same name earlier telling Nature wild birds likely to spread H5N1 to Africa.
What does “conservation group” mean here?
And, does anyone know if Wetlands International has received a wad of money for studying relationship between wild birds and H5N1?
[I’d be v curious to know this generally; how many conservation groups, ecologists, have money for such studies.]
I’ve emailed New Sci, with excerpts of the above; and – after re-read thro the piece – also sent Deborah MacK:Quote:Further, re those ducks.
Know they can carry a low path form of H5N1 without sickening; but excrete only small amounts, with most in respiratory tracts.
Ducks not French kissing, nor prone to sneezing that I’ve noticed. So, how to spread this in wild?
Further, does it matter so much they can spread low path form?
Isn’t all the fuss about highly pathogenic H5N1, which also kills ducks?
Dead Ducks Don’t Fly!
“Every outbreak in east Asia tested since 2004 was caused by a strain of H5N1 known as the “Z genotype”. But birds in Qinghai, and in outbreaks to the west, were infected by a slightly different strain, a hybrid of the Z genotype with its immediate ancestor. “
– yet Nature paper by Guan Yi et al said the Qinghai virus was very similar to strains from se China poultry.
Post edited by: martin, at: 2006/01/28 03:5029 January 2006 at 10:59 am #4061Quote:> The grebe was ‘collected’ on 28 July 2005 at a location where poultry had
> been dying of avian influenza since 15 July.
> The grebe was a juvenile and is reported to have shown no clinical
> symptoms of the disease.
> Subsequently hunters reported mass death of wild birds in the area.
> The obvious explanation — given the timing of the above and the fact the
> bird was a juvenile — is because the grebe had just been infected from
> a poultry source and hadn’t yet succombed to the virus when collected.
Although the above explanation looks most obvious, there may be yet
another possibility. If the bird was “collected” in live, it may have
been infected during handling (after vet’s exposure to poultry).
Since this was still in the early stage of Russian outbreaks, local
vets may have not been yet aware of how contagious this virus is.
We probably need to be extremely careful in interpreting “healthy wild
bird tested positive”.
Both vets and ornithologists should pay specialattention not to become “vectors” to wild individuals — this point is generally missing in guidelines (some only refer to prevention of human infections), and would be especially advisable to newly introduced areas or countries.30 January 2006 at 3:37 pm #4062
comments re this grebe and some other wild birds in Russia that were reported to have H5N1
First by Richard Thomas of Birdlife International;Quote:> >[Readers are referred to 2 drafted scientific papers from the D.I.
> >Ivanovsky Institute of Virology, Russian Academy of Medical Sciences. The
> >papers have been opened for discussion at:
> >The papers include details on “indication of influenza A/H5N1 virus by
> >RT-PCR of cloaca/trachea samples” from 5 species of wild birds “without
> >clinical features”, collected near the center of the epizootic in the
> >Novosibirsk region (July 2005).
> >The birds were: Mallard (_Anas platyrhynchos_), 6/12 positives; Pochard
> >(_Aythya ferina_), 12/33 positives; Great crested grebe (_Podiceps
> >cristatus_), 1/2 positive; Coot (_Fulica atra_), 0/5 and Common tern
> >(_Sterna hirundo_), 0/2. Out of a total of 54 non-clinical wild birds, 19
> >(35.2 percent) were positive.
> >The papers also report the isolation of the A/H5N1 strain
> >A/Grebe/Novosibirsk/29/05 from a Great crested grebe “without clinical
> >features”, collected near the center of the epizootic in the Novosibirsk
> >region (July 2005). – Mod.AS]
> I strongly urge you to read the above papers – and please comment.
Needless to say the blame is laid firmly and squarely on wild birds. There’s
some very important information lacking from the papers, but some very
interesting information included too.
> Particularly lacking is any indication as to how the poultry and wild
birds came into contact. I also couldn’t see any indication of timescales of
the episode: clearly poultry were dying before wild birds became infected,
and it is stated many wild birds later died, but it doesn’t say how long
> I am particularly amazed to see that just over a third of the wild birds
tested were positive (more than 95% of the poultry were positive). There is
some analysis of the genetic strains involved. Of particular interest is
that the strain in poultry is said to be very close to the Qinghai strain.
This means that the strain from the Qinghai area was transported to
Novosibirsk by some means. Given the location, time of year and lack of
spread in other directions from the Qinghai area, wild bird
migration–whilst it can’t be ruled out–would seem to be highly unlikely.
> Hence, poultry or something that had come into contact with infected
poultry/faeces in the QInghai area is far more likely. A quick look at the
atlas and you will see Novobirsk is on a railway connection to Lanzhou, the
large city close to Qinghai.
> Interestingly, FAO has reported Lanzhou as the source of an avian
influenza outbreak in Lhasa, in January 2004 – hence there is already a
precedent for long distance movement of infection from the Qinghai region
(Lanzhou to Lhasa is 1,500 km). The Lhasa outbreak was actually at a poultry
market. [Imagine if those birds hadn’t died at the Lhasa market, but had
been bought by several farmers/local people in the region. We’d have a
sudden near simultaneous outbreak across farms/backyard chickens in Tibet. I
wonder where the blame for the outbreak would be placed?]
> There is no indication in either paper as to whether the poultry involved
were recently transported to Novosibirsk, bred locally or purchased at a
poultry market supplied from elsewhere. This should be investigated, as
should other possible links – perhaps through infected animal/fish-farm
feed. I’m sure you’ll not be surprised to learn that Lanzhou is a major
producer of feed too.
a response to this, from a virologist:Quote:I am afraid one possiibility for many positives in the wild bird species is cross contamination and false positives when PCR alone is used to identify infection. An aliquot of the cloacal sample could be sent to another laboratory for verification.
Post edited by: martin, at: 2006/01/30 07:4312 January 2011 at 8:38 pm #4756AnonymousGuest
Until any scientist claims to have physically isolated the alleged H5N1 Bird Flu virus free from contaminating particles,’coated vesicles’ and other cellular debris that look like viruses but are not, H5N1 will remain a VIRTUAL REALITY.
Since NOBODY has come forth and claimed that they have done precisely that to date, any suggestion that H5N1 is the CAUSE of Bird Flu or anything else is a joke.
When it comes to explaining disease monistic causal doctrines are also a joke when you come to think about it, since they either exclude or ignore the action of all other causes in favour of a single general principle of explanation – VIRUS as CAUSE is the easy and lazy way out in explaining the complex phenomena of a particular disease.
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