French ornitotlogists say wild birds play a minor role in spread.

[Ganseerpel]

Review

Recent expansion of highly pathogenic avian influenza H5N1: a critical review
M. GAUTHIER-CLERC, 1
* C. LEBARBENCHON 1,2
& F. THOMAS
1
Station Biologique de la Tour du Valat, Le Sambuc, 13200 Arles, France
2
GEMI, UMR CNRS/IRD 2724, IRD, 911 av. Agropolis BP 64501, 34394 Montpellier cedex 5, France

Wild birds, particularly waterfowl, are a key element of the viral ecology of avian influenza. Highly pathogenic avian influenza (HPAI) virus, subtype H5N1, was first detected in poultry in November 1996 in southeast China, where it originated. The virus subsequently dispersed throughout most of Asia, and also to Africa and Europe. Despite compelling evidence that the virus has been dispersed widely via human activities that include farming, and marketing of poultry, migratory birds have been widely considered to be the primary source of its global dispersal. Here we present a critical examination of the arguments both for and against the role of migratory birds in the global dispersal of HPAI H5N1. We conclude that, whilst wild birds undoubtedly contribute to the local spread of the virus in the wild, human commercial activities, particularly those associated with poultry, are the major factors that have determined its global dispersal.

full text: http://www.blackwell-synergy.com/doi/full/10.1111/j.1474-919X.2007.00699.x

PS: la Tour du Valat is one of the most important research centers of mediterranian ecology in France

 

[cartski]

Re: French ornitologists say wild birds play a minor role in spread.

Re: French ornitologists say wild birds play a minor role in spread.

Here is a snip from the conclusion to this very interesting paper. It contains the major arguments. (The later paragraphs contain the impact):

J.
__________

The phenology and geographical pattern of expansion of the HPAI H5N1 does not correspond to the pattern of bird migration. First, it took several months for the virus to spread from China to the Balkans. Migratory birds such as ducks and waders travel several hundred kilometres in a single day. If migrating birds mainly dispersed the virus, the virus should also spread by large jumps of thousands of kilometres, throughout the migratory stopping places of Asia and Africa. The observed expansion has rather been by a progressive expansion from isolated outbreaks, the geographical pattern of which corresponds well with major routes and patterns of human commerce. Secondly, from July 2005 onwards, if migratory birds were a main agent of dispersal, one would have expected massive mortalities of wild birds, both in the breeding areas and along all migratory routes, as bird populations would have been encountering this virus for the first time. However, only sporadic cases were observed. The cases in Western Europe after the cold spell on the Black Sea showed that the virus can spread through infected wild birds travelling short distances (Feare 2007), but no evidence for long-distance transmission during seasonal migration has yet been found (Feare 2007). Analysing 52 introduction events into countries, Kilpatrick et al. (2006) concluded that both poultry and the trade in wild birds represent a larger risk than migratory birds for the introduction of HPAI H5N1 to the Americas.

 

[gsgs]

Re: French ornitotlogists say wild birds play a minor role in spread.

since I first saw this debate, I always had the impression that the
ornitologists/birders were biased and not very objective.
They almost always conclude that migratory birds play a minor
role in the spread of H5N1 - should'nt the distribution of opinions
resemble that of other scientists ?

I remember the paper below, which showed a dependance of
H5N1-outbreaks with weather:

http://www.flutrackers.com/forum/showthread.php?t=16644
...
The results show a temperature drop shortly before these outbreaks in birds in each of the Eurasian regions stricken in 2005 and 2006. Dust storms, like those that struck near China's Lake Qinghai around May 4, 2005, exacerbated the spread of this HPAI H5N1 virus, causing the deaths of a record number of wild birds and triggering the subsequent spread of H5N1. Weather monitoring could play an important role in the early warning of outbreaks of this potentially dangerous virus.
...

 

[Ganseerpel]

Re: French ornitotlogists say wild birds play a minor role in spread.

I remember the paper below, which showed a dependance of
H5N1-outbreaks with weather:

The paper supports the hypothesis that odd environmental conditions favor an outbreak but it doesn't state the causality. As mortality in terms of cause of death is far from having been determined in the majority of cases, not all birds must have been dead from infection but could have been victim of unfavorable life conditions. In R?gen there were no more losses than in other years, and this though - in contrast to the past years - winter-feeding had been given up.

 

[Shannon Bennett]

Re: French ornitotlogists say wild birds play a minor role in spread.

Why do I always get the feeling the ornithologists ignore the elephant in the living room? We do not yet know the most likely let alone specific reservoir of flu viruses. Is one species responsible for hosting H5N1 while another is living amiably with H1N1? Are all of them constantly being recirculated in one duck sub group? Perhaps a lone species like the frigate bird that only rarely meets with other species? A rare species would answer a lot of questions. And just as seemingly obvious, domestic birds by definition have evolved to be at least partly dependent on humans for their continued survival. They are also selected for traits that may have nothing to do with surviving HPAI but rather egg production or plumage color. Other species exposed regularly to HPAI would then have a much better chance of living with the disease. So while some wild avian species may only be slightly sick or show no symptoms, domestic birds are wiped out. I do not want to ignore the obvious impact of disease transmission of HPAI in domestic fowl especially in cock-fighting circles but, I do most definitely question it as the primary cause of H5N1 virus dispersal. The elephant in this case is the unknown carrier and ultimate reservoir for the virus. It has been coexisting, incubating and flying for thousands of years if not longer with the scourge, and yet still remains invisible to humans.

 

[cartski]

Re: French ornitotlogists say wild birds play a minor role in spread.

Why do I always get the feeling the ornithologists ignore the elephant in the living room?

I do not want to ignore the obvious impact of disease transmission of HPAI in domestic fowl especially in cock-fighting circles but, I do most definitely question it as the primary cause of H5N1 virus dispersal. The elephant in this case is the unknown carrier and ultimate reservoir for the virus. It has been coexisting, incubating and flying for thousands of years if not longer with the scourge, and yet still remains invisible to humans.

"Elephant in the living room..." - I like that. Reminds of the Peter Seller's movie The Party. Poor animal - glad they washed him/her.

I don't follow how a rare species would provide more answers than what the paper suggests. Geographical epidemiology makes a lot of sense to me especially when dealing with wild vectors. I've always been uneasy with transmission supported by genetic sampling but not necessarily supported by knowledge of migratory patterns.

Besides, how does one move an elephant (e.g. Smokey and the Bandit? )great distances?

J.

 

[HenryN]

Re: French ornitotlogists say wild birds play a minor role in spread.

Why do I always get the feeling the ornithologists ignore the elephant in the living room? We do not yet know the most likely let alone specific reservoir of flu viruses. Is one species responsible for hosting H5N1 while another is living amiably with H1N1? Are all of them constantly being recirculated in one duck sub group? Perhaps a lone species like the frigate bird that only rarely meets with other species? A rare species would answer a lot of questions. And just as seemingly obvious, domestic birds by definition have evolved to be at least partly dependent on humans for their continued survival. They are also selected for traits that may have nothing to do with surviving HPAI but rather egg production or plumage color. Other species exposed regularly to HPAI would then have a much better chance of living with the disease. So while some wild avian species may only be slightly sick or show no symptoms, domestic birds are wiped out. I do not want to ignore the obvious impact of disease transmission of HPAI in domestic fowl especially in cock-fighting circles but, I do most definitely question it as the primary cause of H5N1 virus dispersal. The elephant in this case is the unknown carrier and ultimate reservoir for the virus. It has been coexisting, incubating and flying for thousands of years if not longer with the scourge, and yet still remains invisible to humans.

These papers are well beyond the elephant in the living room. It is well known that detection of H5N1 in live wild birds is VERY difficult, so ornithogists generate massive amounts of negative data and then publish utter nonsense (like no H5N1 in Africa).

These papers are part of a rather obvious agenda.

 

[Ganseerpel]

Re: French ornitotlogists say wild birds play a minor role in spread.

It is well known that detection of H5N1 in live wild birds is VERY difficult, so ornithogists generate massive amounts of negative data and then publish utter nonsense (like no H5N1 in Africa).

When it is there, it is not much more difficult than any other AI virus, in terms of virus detection, though methodical problems may play a role. Data of the available surveillance studies show a widely variable over-all- prevalence depending on geographic and seasonal circumstances and observation period.

 

[Shannon Bennett]

Re: French ornitotlogists say wild birds play a minor role in spread.

The rare animal equals the rare encounter. There is no doubt the geographical spread is difficult to explain. There are a couple of possibilities.

If all wild ducks in a given flock, as an example, were infected they then would infect all other ducks they met on a flyway or coexisted nearby. Then every pond along the flyways would be viral soups and infection centers and all susceptible birds visiting them would then be infected as the birds intermingled. We would see a steady geographical spread in our pattern emanating from the epicenter outwards. It would not account for the sporadic spread we see now.

If the infection were passed in a chain migration pattern we would see the ponds along flyways littered with a steadily decreasing number of avian corpses from the point of origin to the eventual last dead bird located at some distance from the first sick/dead bird. But only if the virus were able to infect only one family of bird. We already know the virus can infect many species not even remotely related. That pattern then if it were a typical chain migration would look very different. Instead of seeing a drop-off in the number of dead birds you would see an increasing number of corpses as new susceptible species were encountered. There are two things wrong with this scenario. The first is we don't see a typical bell curve of bird deaths with the highest number near the original site of infection with few occurring outward along flight paths. The only exception to this was the outbreak in Qinghai. Neither are we seeing a steadily larger pool of infected and dying birds spreading outwards from Southern China. The pattern then doesn't fit the template of typical chain migration coupled with additional host species.

The argument for commercial trade of domestic birds as the primary source of infection ignores the rapid deaths of domestic birds. Any conclave of commercial bird raisers would take immediate note of a competitors sudden loss of fowl. It would be virtually impossible to hide the illness. Flocks don't die over a period of months but rather in a few days. Buyers of the flocks would be forced to purchase new birds swiftly from new sources as their previously contracted producers suddenly were unable to meet quotas. Arguments listing one grower meeting another and somehow then passing the virus unbeknownst to the second are spurious. Virus don't live long outside of a moist cool environment. While arguments stating one man visiting a convention of poultry raisers and leaves infected chicken manure where another could track it home are indeed far-fetched.

Birds from small to medium sized flocks are more likely to be one of the causal sources for infection. Also too are birds used for cock-fighting. But again we run into the problem of the rapid death of domestic birds. If the primary spread were due to cock-fighting then by now all birds raised for that purpose would be infected. One sick bird could infect virtually all of the birds brought to a cock fight. These birds then would be returned home where they would infect the rest of the flock. In many parts of the world where H5N1 is endemic, birds are free range. And in cases where the cockerels were caged we have not heard an outcry from devoted owners of the sudden death of all their prized stock at least on a massive scale. We don't have any data that I have read about this kind of geographical spread. The only exception to this would be if cock-fighting in all affected areas was limited to a time-span that prevented re-infection of new fighting cocks. For instance, cock-fighting was only held on the third Thursday of each month. It is my understanding this is not the case. In fact on any given day you can watch a fight in much of South East Asia.

Backyard flocks also have the same limiting factor. Birds die quite suddenly. How too do you account for those on the other side of natural barriers such as oceans or mountain ranges to suddenly acquire the virus with no known hosts between the two? The argument that dead birds don't fly is far more applicable to domestic fowl then it is to wild birds. You could make an argument for the spread of the disease through backyard flocks if the pattern spread outward steadily from a central location. I find it hard to support the thesis that visitors from China smuggle fowl under their coats to Azerbaijan or Turkey without arriving with either a dead or severely ill bird. I also am convinced anecdotal stories to corroborate a visiter from another country preceded the deaths of Joe Farmers flock in Central Africa.

So where is the infection coming from? I wish I knew. I surmise the routes are not limited to one pathway. I am virtually certain that domestic flocks have played a role. But, I am more convinced wild birds are the larger vector. We already know the virus in all of its forms is found in waterfowl. That is where we initially identified the different strains. We also know that at least some waterfowl survive the infections with few symptoms. We may add a number of other bird species are also susceptible to the virus some more so than others i.e. swans. Add to that some birds are not limited to a specific geographical location and can indeed cross mountain ranges and oceans. We also now know the geographical epicenter appears to be in Guandong, China. So, we are left with reconciling the pattern we see with a template that matches. The obvious pathways I mentioned above do not fit. However, one possible explanation would be if the real reservoir of avian influenza was in a fairly rare species. Ducks and other waterfowl then might be intermediate hosts and occasional vectors rather than responsible for the whole reservoir.

The virus has to not kill its host or it will go the way of the dodo bird. If it didn't do this we wouldn't be worried about a pandemic today. Guandong is not in the Arctic so the argument for overwintering in frozen ponds is specious. It has to be circulating in some species and not killing its hosts all the time. Ipso facto it cannot be in a commercial breed for as we know domestic fowl are killed quickly. It cannot be in a common bird or again ipso facto we would have seen a far more rapid and predictable spread of the disease and a much faster reoccurrence of all the strains. I am not familiar with many of the bird species in that part of the world but, as a geographer I would begin to focus my attention on a rare species that sometimes comes into contact with domestic birds in Guandong China. It may not be the answer but it would fit the pattern.

 

[HenryN]

Re: French ornitotlogists say wild birds play a minor role in spread.

When it is there, it is not much more difficult than any other AI virus, in terms of virus detection, though methodical problems may play a role. Data of the available surveillance studies show a widely variable over-all- prevalence depending on geographic and seasonal circumstances and observation period.

The teal in Egypt was negative initially. It took additional steps to detect the H5N1 that was clearly THERE (and in Africa, negative nonsense not withstanding)

LOCUS EF042624 1596 bp cRNA linear VRL 15-NOV-2006
DEFINITION Influenza A virus (A/teal/Egypt/14051-NAMRU3/2005(H5N1))
hemagglutinin (HA) gene, partial cds.
ACCESSION EF042624
VERSION EF042624.1 GI:117395044
KEYWORDS .
SOURCE Influenza A virus (A/teal/Egypt/14051-NAMRU3/2005(H5N1))
ORGANISM Influenza A virus (A/teal/Egypt/14051-NAMRU3/2005(H5N1))
Viruses; ssRNA negative-strand viruses; Orthomyxoviridae;
Influenzavirus A.
REFERENCE 1 (bases 1 to 1596)
AUTHORS Saad,M.D., Gamal-Eldein,M.A., Ahmed,L.S., Yingst,S.L., Parker,M.A.
and Monteville,M.R.
TITLE Possible Introduction of Avian Influenza H5N1 in Egypt by a
Migratory Bird
JOURNAL Unpublished
REFERENCE 2 (bases 1 to 1596)
AUTHORS Saad,M.D., Gamal-Eldein,M.A., Ahmed,L.S., Yingst,S.L., Parker,M.A.
and Monteville,M.R.
TITLE Direct Submission
JOURNAL Submitted (04-OCT-2006) Viral and Zoonotic Diseases Research
Program, U.S. Naval Medical Research Unit No. 3, Extension of
Ramses Street, Nasr City, Cairo 11517, Egypt
FEATURES Location/Qualifiers
source 1..1596
/organism="Influenza A virus
(A/teal/Egypt/14051-NAMRU3/2005(H5N1))"
/mol_type="viral cRNA"
/strain="A/teal/Egypt/14051-NAMRU3/2005"
/serotype="H5N1"
/isolation_source="cloacal swab"
/specific_host="teal duck"
/db_xref="taxon:409944"
/segment="4"
/country="Egypt: Damietta governorate"
/collection_date="Dec-2005"
gene <1..>1596
/gene="HA"
CDS <1..>1596
/gene="HA"
/codon_start=3
/product="hemagglutinin"
/protein_id="ABK34513.1"
/db_xref="GI:117395045"
/translation="YHANNSTEQVDTIMEKNVTVTHAQDILEKTHNGKLCDLDGVKPL
ILRDCSVAGWLLGNPMCDEFLNVPEWSYIVEKINPANDLCYPGNFNDYEELKHLLSRI
NHFEKIQIIPKSSWSDHEASSGVSSACPYQGRSSFFRNVVWLIKKDNAYPTIKRSYNN
TNQEDLLVLWGIHHPNDAAEQTRLYQNPTTYISVGTSTLNQRLVPKIATRSKVNGQSG
RMEFFWTILKPNDAINFESNGNFIAPENAYKIVKKGDSTIMKSELEYGNCNTKCQTPI
GAINSSMPFHNIHPLTIGECPKYVKSNRLVLATGLRNSPQGERRRKKRGLFGAIAGFI
EGGWQGMVDGWYGYHHSNEQGSGYAADKESTQKAIDGVTNKVNSIIDKMNTQFEAVGR
EFNNLERRIENLNKKMEDGFLDVWTYNAELLVLMENERTLDFHDSNVKNLYDKVRLQL
RDNAKELGNGCFEFYHRCDNECMESVRNGTYDYPQYSEEARLKREEISGVKLESIGTY
QILSIYSTVASSLALAIMVAGLS"
ORIGIN
1 gttaccatgc aaacaactcg acagagcagg ttgacacaat aatggaaaag aacgtcactg
61 ttacacacgc ccaagacata ctggaaaaga cacacaacgg gaaactctgc gatctagatg
121 gagtgaagcc tctaatttta agagattgta gtgtagctgg atggctcctc gggaacccaa
181 tgtgtgacga attcctcaat gtgccggaat ggtcttacat agtggagaag atcaatccag
241 ccaatgacct ctgttaccca gggaatttca acgactatga agaactgaaa cacctattga
301 gcagaataaa ccattttgag aaaattcaga tcatccccaa aagttcttgg tcagatcatg
361 aagcctcatc aggggtgagc tcagcatgtc cataccaggg aaggtcctcc ttttttagaa
421 atgtggtatg gcttatcaaa aaggacaatg crtacccaac aataaagaga agttacaata
481 ataccaacca agaagatctt ttggtactgt gggggattca ccatccaaat gatgcggcag
541 agcagacaag gctctatcaa aacccaacta cctatatttc cgttgggaca tcaacactaa
601 accagagatt agtaccaaaa atagctacta gatctaaggt aaacgggcaa agtggaagga
661 tggagttctt ttggacaatt ttaaaaccga atgatgcaat aaactttgag agtaatggaa
721 atttcattgc tccagaaaat gcatacaaaa ttgtcaagaa aggggactca acaattatga
781 aaagtgagtt ggaatatggt aactgcaaca ccaagtgtca aactccaata ggggcgataa
841 actctagtat gccattccac aacatccacc ctctcaccat cggggaatgc cccaaatatg
901 tgaaatcaaa cagattagtc cttgctactg ggctcagaaa cagccctcaa ggagagagaa
961 gaagaaaaaa gagaggacta tttggagcta tagcaggttt tatagaggga ggatggcagg
1021 gaatggtaga tggttggtat gggtaccacc atagcaacga gcaggggagt gggtacgctg
1081 cagacaaaga atccactcaa aaggcaatag atggagtcac caataaggtc aactcgatca
1141 ttgacaaaat gaacactcag tttgaggctg ttggaaggga atttaataac ttagaaagga
1201 gaatagaaaa tttaaacaag aagatggaag acggattcct agatgtctgg acttataatg
1261 ctgaacttct ggttctcatg gaaaatgaga gaactctaga ctttcatgac tcaaatgtca
1321 agaaccttta cgacaaggtc cgactacagc ttagggataa tgcaaaggag cttggtaacg
1381 gttgtttcga gttctatcac agatgtgata atgaatgtat ggaaagtgta agaaacggaa
1441 cgtatgacta cccgcagtat tcagaagaag caagattaaa aagagaggaa ataagtggag
1501 taaaattgga atcaatagga acttaccaaa tactgtcaat ttattcaaca gtggcgagct
1561 ccctagcact ggcaatcatg gtggctggtc tatctt

http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=117395044

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=Nucleotide&cmd=Search&dopt=DocSum&term=txid409944[Organism:noexp]

 

[Ganseerpel]

Re: French ornitotlogists say wild birds play a minor role in spread.

The problems start with the denomination:
"Teal" is not a taxonomic denomination. I could not find more precise information

It includes:

• Cinnamon teal [Anas cyanoptera]
• Ringed Teal,Callonetta leucophrys
• The Common Teal, Anas crecca
• Green-winged Teal, Anas carolinensis
• Black Teal, Aythya novaeseelandiae
• Brown Teal, Anas aucklandica
• Silver Teal, Anas versicolor
• Cape Teal, Anas capensis
• Marbled Teal, Marmaronetta angustirostris
• Blue-winged Teal, Anas discors ?

If we want to clear up cause and effect in terms of spread by migration we need additional information including ornithological, veterinary, serological data (which lacks in many if not most of the cases).

 

[HenryN]

Re: French ornitotlogists say wild birds play a minor role in spread.

The problems start with the denomination:
"Teal" is not a taxonomic denomination. I could not find more precise information

It includes:

• Cinnamon teal [Anas cyanoptera]
• Ringed Teal,Callonetta leucophrys
• The Common Teal, Anas crecca
• Green-winged Teal, Anas carolinensis
• Black Teal, Aythya novaeseelandiae
• Brown Teal, Anas aucklandica
• Silver Teal, Anas versicolor
• Cape Teal, Anas capensis
• Marbled Teal, Marmaronetta angustirostris
• Blue-winged Teal, Anas discors ?

If we want to clear up cause and effect in terms of spread by migration we need additional information including ornithological, veterinary, serological data (which lacks in many if not most of the cases).

The story is in the sequence, and the migration patterns are quite clear. The bird was alive and migratory.

Very few have identified H5N1 in live birds, because the assays used cannot detect Qinghai H5N1 in live wild birds.

Ornithologists have flooded the news media and journals with negative data, which is pure nonsense. They failed to find H5N1 in Africa, which pretty much sums up their efforts (and propaganda).

The sequneces in wild birds, domestic poultry, and humans paint a VERY clear picture of H5N1 migration via wild birds.

 

[Anne]

Re: French ornitotlogists say wild birds play a minor role in spread.

doctor Niman,do you have something clear about Hungary and Bernard Mattews turkey
and chinese one day chickens and Nigeria ?
it's not clear for me..

 

[HenryN]

Re: French ornitotlogists say wild birds play a minor role in spread.

The problems start with the denomination:
"Teal" is not a taxonomic denomination. I could not find more precise information

It includes:

• Cinnamon teal [Anas cyanoptera]
• Ringed Teal,Callonetta leucophrys
• The Common Teal, Anas crecca
• Green-winged Teal, Anas carolinensis
• Black Teal, Aythya novaeseelandiae
• Brown Teal, Anas aucklandica
• Silver Teal, Anas versicolor
• Cape Teal, Anas capensis
• Marbled Teal, Marmaronetta angustirostris
• Blue-winged Teal, Anas discors ?

If we want to clear up cause and effect in terms of spread by migration we need additional information including ornithological, veterinary, serological data (which lacks in many if not most of the cases).

Here's a live healthy great crested grebe (Podiceps cristatus) in Russia

http://www.ncbi.nlm.nih.gov/entrez/viewer.fcgi?db=nucleotide&val=76097668

The story remains in the sequence (Qinghai, Clade 2.2)

LOCUS DQ190857 271 bp RNA linear VRL 27-SEP-2005
DEFINITION Influenza A virus (A/grebe/Novosibirsk/29/05(H5N1)) hemagglutinin
(HA) gene, partial cds.
ACCESSION DQ190857
VERSION DQ190857.1 GI:76097668
KEYWORDS .
SOURCE Influenza A virus (A/grebe/Novosibirsk/29/2005(H5N1))
ORGANISM Influenza A virus (A/grebe/Novosibirsk/29/2005(H5N1))
Viruses; ssRNA negative-strand viruses; Orthomyxoviridae;
Influenzavirus A.
REFERENCE 1 (bases 1 to 271)
AUTHORS Lvov,D.K., Shchelkanov,M.Y., Deryabin,P.G., Grebennikova,T.V.,
Prilipov,A.G., Nepoklonov,E.A., Onishchenko,G.G., Vlasov,N.A.,
Aliper,T.I., Zaberezhny,A.D., Kireev,D.E., Krascheninnikov,O.P.,
Kiryukhin,S.T., Burtceva,E.I. and Slepuschkin,A.N.
TITLE Isolation of Influenza A/H5N1 virus strains from poultry and wild
birds during epizootic outbreak in Western Siberia (July 2005) and
their incorporation in Russian State Collection of Viruses (August
08, 2005)
JOURNAL Vopr. Virusol. (2005) In press
REFERENCE 2 (bases 1 to 271)
AUTHORS Lvov,D.K., Shchelkanov,M.Y., Deryabin,P.G., Grebennikova,T.V.,
Prilipov,A.G., Nepoklonov,E.A., Onishchenko,G.G., Vlasov,N.A.,
Aliper,T.I., Zaberezhny,A.D., Kireev,D.E., Krascheninnikov,O.P.,
Kiryukhin,S.T., Burtceva,E.I. and Slepuschkin,A.N.
TITLE Direct Submission
JOURNAL Submitted (01-SEP-2005) Virus Evolution and Ecology, D.I. Ivanovski
Virology Institute, 16 Gamalei Str., Moscow 123098, Russia
FEATURES Location/Qualifiers
source 1..271
/organism="Influenza A virus
(A/grebe/Novosibirsk/29/2005(H5N1))"
/mol_type="genomic RNA"
/strain="A/grebe/Novosibirsk/29/05"
/serotype="H5N1"
/isolation_source="great crested grebe (Podiceps
cristatus) without clinical signs of influenza"
/db_xref="taxon:353252"
/country="Russia"
/note="type: A"
gene <1..>271
/gene="HA"
CDS <1..>271
/gene="HA"
/codon_start=3
/product="hemagglutinin"
/protein_id="ABA39516.1"
/db_xref="GI:76097669"
/translation="INSSMPFHNIHPLTIGECPKYVKSNRLVLATGLRNSPQGERRRK
KRGLFGAIAGFIEGGWQGMVDGWYGYRHSNEQGSGYAADKESTQKA"
ORIGIN
1 tgataaattc tagcatgcca ttccacaaca tccaccctct caccatcggg gaatgcccca
61 aatatgtgaa atcaaacaga ttagtccttg cgactgggct tagaaatagc cctcaaggag
121 agagaagaag aaaaaagaga ggactatttg gagctatagc aggttttata gagggaggat
181 ggcagggaat ggtagatggt tggtatgggt accgccatag caacgagcag gggagtgggt
241 acgctgcaga caaagaatcc actcaaaagg c

 

[Ganseerpel]

Re: French ornitotlogists say wild birds play a minor role in spread.

There is no doubt that wild birds can survive infection with quinhai strains, as verification of H5 Ab's in swans shows clearly. Another question is, if really, at no time point, there are no clinical signs present. In swans it has been shown that even LPAI infection reduces fitness and migratory performance.

On the other hand it is noteworthy that in the cited article the presence of HPAI infection in clinically healthy poultry. It is not specified what kind of poultry was involved and if it was livestock farming or industrial husbandry.

(Vopr Virusol. 2006 Jan-Feb;51(1):11-4. Links
[Isolation of influenza A/H5N1 virus strains from poultry and wild birds in West Siberia during epizooty (July 2005) and their depositing to the state collection of viruses (August 8, 2005)][Article in Russian]
L'vov DK, Shchelkanov MIu, Deriabin PG, e a)

 

[canagica]

Re: French ornitotlogists say wild birds play a minor role in spread.

The rare animal equals the rare encounter. There is no doubt the geographical spread is difficult to explain. There are a couple of possibilities...
...It has to be circulating in some species and not killing its hosts all the time. Ipso facto it cannot be in a commercial breed for as we know domestic fowl are killed quickly. It cannot be in a common bird or again ipso facto we would have seen a far more rapid and predictable spread of the disease and a much faster reoccurrence of all the strains. I am not familiar with many of the bird species in that part of the world but, as a geographer I would begin to focus my attention on a rare species that sometimes comes into contact with domestic birds in Guandong China. It may not be the answer but it would fit the pattern.

I think you bring up a good point-that there is no concrete pattern, and that rarity probably plays a big role in H5N1 transmission; however, as Ganserspeel points out, there can even be asymptomatic poultry (which indicates domestic fowl aren't necessarily unimpeachable). Tests of cages in markets turned up HPAI H5N1, smuggled birds have turned up H5N1, asymptomatic wild waterfowl have been found (though the methods used to determine the migratory status have been questioned), plus poorly conducted vaccination attempts may also be masking the prevalence of H5N1 in poultry flocks.

It seems like a different way to view the issue is to not constrain thinking to a "rare species", but rather to rare events (or a group of rare events). It's an issue of probability:

What is the likelihood of infected chicken manure in cages transferring the pathogens long distance?
What is the chance of infected wild or domestic birds being smuggled into a country? Imported legally?
What is the likelihood of LPAIs getting into domestic flocks and mutating?
What is the likelihood of an asymptomatic HPAI H5N1 wild migratory bird overlapping with/infecting domestic poultry or ducks?
What about asymptomatic non-migratory birds? Felines/carnivores? etc.

For each of these "rare events", geography, politics, biosecurity, etc. play a role in assigning a probability. No one contests that LPAIs are endemic in waterfowl, and that they are the natural reservoir; but a template such as the one you describe that takes into account each of these possible vectors for transmitting AIs might better reflect the reality that there are a complex set of interacting factors that have differential influences on the spread of H5N1 that change based on geography, etc.

 

[HenryN]

Re: French ornitotlogists say wild birds play a minor role in spread.

I think you bring up a good point-that there is no concrete pattern, and that rarity probably plays a big role in H5N1 transmission; however, as Ganserspeel points out, there can even be asymptomatic poultry (which indicates domestic fowl aren't necessarily unimpeachable). Tests of cages in markets turned up HPAI H5N1, smuggled birds have turned up H5N1, asymptomatic wild waterfowl have been found (though the methods used to determine the migratory status have been questioned), plus poorly conducted vaccination attempts may also be masking the prevalence of H5N1 in poultry flocks.

It seems like a different way to view the issue is to not constrain thinking to a "rare species", but rather to rare events (or a group of rare events). It's an issue of probability:

What is the likelihood of infected chicken manure in cages transferring the pathogens long distance?
What is the chance of infected wild or domestic birds being smuggled into a country? Imported legally?
What is the likelihood of LPAIs getting into domestic flocks and mutating?
What is the likelihood of an asymptomatic HPAI H5N1 wild migratory bird overlapping with/infecting domestic poultry or ducks?
What about asymptomatic non-migratory birds? Felines/carnivores? etc.

For each of these "rare events", geography, politics, biosecurity, etc. play a role in assigning a probability. No one contests that LPAIs are endemic in waterfowl, and that they are the natural reservoir; but a template such as the one you describe that takes into account each of these possible vectors for transmitting AIs might better reflect the reality that there are a complex set of interacting factors that have differential influences on the spread of H5N1 that change based on geography, etc.

The story is in the sequence. No Qinghai west of China prior to Qinghai Lake.

 

[sharon sanders]

Re: French ornitotlogists say wild birds play a minor role in spread.

Thanks everyone for such an illuminating thread.

Clearly the spread of H5N1, or any other disease, involves a myriad of factors as stated above by Canagica. Spread by wild birds is only one method.

One of the major control measures for the spread of H5N1 is the disposal on site of dead infected poultry. The transportation of dead carcasses to disposal areas and the resultant debris is another potential spread mechanism. The list of "spread vectors" is endless.

One control method that does not work is the elimination of wild birds. This is a not a realistic control measure. We must control our immediate environments (home, work, etc) and use various methodologies to control our personal exposure (frequent hand-washing, etc.).

 

[sharon sanders]

Re: French ornitotlogists say wild birds play a minor role in spread.

Thanks Pam for a "first-hand" account.

http://www.flutrackers.com/forum/showpost.php?p=75033&postcount=2

 

[canagica]

Re: French ornitotlogists say wild birds play a minor role in spread.

The story is in the sequence. No Qinghai west of China prior to Qinghai Lake.

I don't completely understand the importance of your statement; it would seem that, regardless of where an epidemic/epizootic occurs, that once that strain is introduced or found, that it may be transmitted via the same potential routes as any other strain of H5N1; so, even if you feel the evidence strongly points to migratory birds as being the source of the Qinghai outbreak (and there is some discussion due to the presence of captive rearing programs for Bar-headed Geese along the shores of Qinghai Lake), unless there is no possible way other than migratory birds for that virus to be transmitted from that location (e.g. planes, trains, and automobiles related to trade/smuggling/culture/etc?), that further expansion would need to be evaluated based on some of the factors mentioned previously in this thread.

Note that I am not saying that it's not possible, but that I don't understand why it has to be migratory birds, so maybe there's something fundamental that I am missing; can you fill me in on why the sequence would be singularily illuminating?

(sorry if this thread is the wrong forum to ask this question of Dr. Niman)