Wildvögel und H5N1

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Update on the Avian Influenza situation
(As of 19/06/2006) – Issue no. 40
The information summarized below is gathered from official and non official sources, which are quoted in the
text. AIDE news is prepared by the FAO Technical Task Force on Avian Influenza.

Should wild birds now be considered a permanent reservoir of the virus?
The animal species playing a role in the transmission, spread or introduction of the highly pathogenic avian influenza (HPAI) H5N1 virus are essentially domestic and wild birds.
Although some fifty non-domestic bird species have proved susceptible to infection from the virus, it would appear from the epidemiological data currently available that, among the wild birds implicated in the transboundary introduction of the virus, aquatic birds play a major role.
In most European countries where the H5N1 virus has appeared, it has been with wild birds. In East and Southeast Asia, the disease was arguably spread by a combination of domestic and wild birds, while in Africa it appears that the poultry trade, both legal or informal, and traffic were responsible. No doubt more field (retrospective) work is
required.

http://www.fao.org/docs/eims/upload/...AVIbull040.pdf

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Aus dem Paper von Domenech ea (FAO)
http://www.fao.org/docs/eims/upload/...e_aug07_ai.pdf

According to the Friedrich Loeffler Institute,
phylogenetic analysis of the Czech isolate for HA1 reveals closest genetic similarity (99.5% at the nucleotide level) to recent viruses isolated from poultry and ‘captive hunting’ falcons in Kuwait in March 2007. These isolates group more widely with contemporary and 2006
strains from Bangladesh, Pakistan, and Azerbaijan, but they appear to be less related to viruses isolated from both wild birds and poultry
during the outbreaks in EU Member States in 2006 and different from the viruses obtained during outbreaks in Hungary and the UK at the
beginning of 2007. Therefore, the current outbreak in Europe represents a new introduction of virus into Europe, however the source remains unknown.,

Was halten wir denn davon?

[HCS]

Na, da müsste man doch mal nachschauen, wo der tschechische Betrieb sein Futter her hatte. Zugvögel sind ja eher unwahrscheinlich, wegen Jahreszeit und Herkunft des Virus, überwinterte Viren scheiden definitiv aus, damit wird die Wildvogel-Hypothese höchst fraglich, und da fällt einem dann doch am ehesten das Futter ein.

Hans-Christoph

[gsgs]

koennte doch mit den Lebensgewohnheiten der Wildvoegel zusammenhaengen, z.B. fluegge werdende Jungschwaene,
Mauser oder so.

Ist es denn Zufall, dass Gefluegelbetriebe und Schwaene,
Haubentaucher jetzt gleichzeitig H5N1 haben ?

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@ Deufy

On s'achemine de plus en plus vers une reconnaissance unanime de ces évidences :
1. les oiseaux migrateurs ne sont pas responsables de la propagation de l'épizootie.
2. les oiseaux d'eau sont des révélateurs de la présence du virus dans l'environnement ("sentinelles" ou "agents de surveillance passive") parce que celui-ci est plus persistant (dans des proportions contaminantes) dans l'eau (...que dans l'air, la terre, le feu, ou le vide intersidéral ).

Quoi qu'il en soit, le suivi des sequences montre clairement -
- une diversité croissante de souches circulantes, ce qui laisse supposer une évolution relativement longue dans des multiples foyers.
- un nombre considérable de cas dans le o. sauvages dans des zones, voire des pays où jamais des installations avicoles n'étaient atteintes.
- Des rapports génétiques Europe /Afrique /Asie centrale donc des sites géographiquement très distants.
- Avant la survenue du clade 2.2 (Qinghai) en 2005 (peutêtre 2004) le H5 n'a jamais été observé à l'ouest de la Chine, alors que tous les "phénomènes de civilisation humaine", traffic de volaille, fientes/engrais infectées, rôle de la FAO étaient bien existants.

4. Les virus aviaires sont présents - "endémique" ? - dans la filiaire avicole industrielle mondiale et s'épanouïssent plus particulièrement dans les élevages industriels de dindes.

La base de cette hypothèse n'a jamais été mise en evidence- du moins en dehors des pays est-asiatiques - et cela malgré d'un bon nombre de programmes de surveillance intensive.

5. il existe un problème en Europe centrale et de l'Est, dont les élevages, dans des installations parfois vétustes et délabrées, ne peuvent être efficacement et hermétiquement isolés par rapport à des régions voisines où des épizooties de grande ampleur ont été constatées en 2005/2006 (Roumanie, Bulgarie, Ukraine) et où le recours à la vaccination généralisée a pour conséquence de laisser le virus circuler discrétement - "à bas bruit" - (Russie).
6. La persistance du H5N1 HP dans les biotopes contaminés, et sa volatilité apparente rendent inopérante la prophylaxie fondée sur "l'éradication des foyers en anneaux". L'OIE et l'U.E. seront conduites à reconnaître la faillite de leur stratégie de lutte contre l'expansion de l'épizootie. Et tôt ou tard, l'U.E. en viendra à précoiser la vaccination généralisée de l'ensemble de ses volailles et oiseaux domestiques, plutôt que de les détruire, comme cela se pratique en Afrique ou aux Pays Bas ...

Cela s'impose en effet. Ceci étant dit, malgré les risques associés à une campagne de vaccination.

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FAO: Guidelines on wild bird surveillance for H5N1
Vittorio Guberti & Scott H.. Newman
1 Istituto Nazionale Fauna Selvatica, Ozzano E. (BO), Italy
2 Wildlife Conservation Society, Bronx, NY, USA
3 Food and Agriculture Organization, Rome, Italy
Power point presentation

Wildlife Surveillance for H5N1
• Difficult to accomplish
• Complicated in nature, especially logistics
• Will require a large, coordinated team(s)
• Many things can (and will) go wrong
• Planning is almost as important as field sampling to
ensure that things go as smoothly as possible
• Targeted species testing, not random
• Collect samples from both live and dead birds
• Concurrently collect additional surveillance samples (serology, heavy metals, ecotoxins, isotope work, genetics, etc.

OBJECTIVES OF EPIZOOTIOLOGICAL SURVEILLANCE STUDIES
• Epidemiological (humans) sampling or epizootiological (animals) sampling is based testing large numbers of individuals but extrapolating results to populations
– Determine prevalence of disease (endemic or not)
– Determine its significance to the population
– Describe & characterize the environmental variables associated with disease emergence – Identify factors that may lead to disease emergence
(natural history, ecology, anthropogenic activities, etc.)
– Determine methods to monitor, prevent, control, & reduce disease
– Identify management steps that can be taken to minimize disease transmission with an emphasis on preventing transmission to agricultural species and humans

Families & Species Found by FAO/OIE to Be Positive as of 15 May 2006
● Accipitridae ● Falconidae
– Northern Goshawk – Common Kestrel
– Common Buzzard – Peregrine Falcon
– Rough-Legged Hawk
● Strigidae ● Sturnidae
– Eagle Owl – Crested Myna
● Corvidae
– Crows (House, Carrion, Jungle or Large-Billed)
– Common Magpie
● Zosteropidae ● Columbidae
– Japanese White-Eye – Collared Dove
● Anatidae
– Ducks (Northern Pintail, Mallard, Smew, Greater Scaup, Tufted Duck, Common Merganser, Pochard & Scoter)
– Geese (Lesser White-Fronted, Grey-Lag, Canada)
– Swan (Whooper, Mute)
● Rallidae ● Ardeidae
– Coots (American, Common) – Gray Heron, Little Egret
● Laridae ● Phalacrocoracidae
– Gull (Herring, Black-Headed – Great Cormorant
● Podicipedidae
– Great Crested Greb

Can we make a “top 10” list of species to sample ?
• YES
• But…….the list will change wherever sampling is performed
• Multiple factors contribute to decision involved in what species to sample

International Wildlife Surveillance
• Based on cllearlly defiined aiims
• Based on sound epiidemiiollogiicall justtificattions for sampling
• Requires suffiicient technical skills from biollogists,, veterinarians,, and others
– Conducting field work (bird captures/sampling) to ensure that quality samples are collected in a minimally invasive way, stored and transported appropriately
– Approved laboratory

International Wildlife Surveillance
• Should contain 3 parts:
1) Passive Surveillance
– Rehabilitation centers
– Oil spill response efforts
– Zoological collections
– Bird banders/ringers
– Other wild bird research
– Mortality event investigations
– Hunters
– Beached birds survey
programs methods that meet FAO/OIE standards
• Requiires exttensiive collaboration
• Should partsShould contain 3 parts:
2) Actiive Surveillance
– Species that have died from H5N1
– Species known to be carriers of other Avian Influenza viruses
– Species that are social and occur in high aggregations at certain times of the year
– Species that potentially use habitat near poultry/duck/goose farms or back yard flocks
– Species that have seasonal movements or migratory patterns that may explain disease emergence from country to country, or trans-continentally

CLINICAL STUDIES NECESSARY TO COMPLIMENT SURVEILLANCE ACTIVITIES
• Clinical studies- based on individuals & determine cause-effect relationships between host (wild birds) & pathogen (H5N1)
– If exposed, do wild birds become clinically ill, develop immunity and survive, die, or some combination ?
– If exposed, do wild birds shed virus? If so, for how long after exposure?
– If exposed, are birds healthy enough to migrate ?
– If yes, for how many days do they shed virus while on the move ?
– Are there species differences as far as disease
susceptibility, virus shedding, ability to migrate, etc.?

Take Home Points
• Both live and dead bird surveillance is warranted
• More funding is necessary to start to understand disease prevalence among wildlife species
• We can make a top 10 species list, but understanding the variables that guide decisions as to which birds to sample is more important, and factors will vary regionally
• If surveillance is conducted, a wildlife contingency plan should exist and a mechanism to respond to positive test results should be in place
• To fully understand the disease ecology, we need a combination of clinical studies, wildlife surveillance results, and ecological information

Unhealthy Ecosystems
Loss of ecosystem services
A high prevalence of disease is one of the key indicators of ecosystem pathology
A sick ecosystem iincreases the health risks of its components (other speciies)
Rapport 1999
BSE
Avian Malaria
Lyme Disease
Chytridiomycosis
Avian influenza
Tick Borne Encephalitis
Human Malaria
Monkey Pox
Nipah Virus
SARS

Health connects all species

http://www.fao.org/ag/againfo/subjec...rti-Newman.pdf

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Influenza surveillance in wild birds in Eastern Europe, the
Middle East, and Africa: preliminary results from an ongoing FAO-led survey
---------------------------------------------------------------------------
From mid-January to mid-May 2006, field campaigns were conducted in
14 countries, including recently infected countries. In total, 5256
samples were collected in large wetland areas where Eurasian and
Afro-tropical waterbirds congregate. The overall prevalence of avian
influenza viruses detected by RT-PCR was 3.3 percent, with no
positivity for HPAI H5N1 virus. From the RT-PCR-positive samples, 5
distinct virus isolates were obtained. Low pathogenic avian influenza
(LPAI) viruses were detected and isolated in both Eurasian and
Afro-tropical bird species, indicating that low pathogenic viruses
were circulating in Africa during the northern winter. These findings
reveal that LPAI virus persists in wild birds in subtropical
environments and support the hypothesis that avian influenza viruses
could be perpetuated in wild birds throughout the year, including in
Palearctic waterbirds wintering in sub-Saharan Africa before their
northward spring migration.

[Reference: Nicolas Gaidet, Tim Dodman, Alexandre Caron, Gilles
Balanca, Stephanie Desvaux, Flavie Goutard, Giovanni Cattoli, Vincent
Martin, Astrid Tripodi, Francois Lamarque, Ward Hagemeijer, Francois
Monicat: Influenza surveillance in wild birds in Eastern Europe, the
Middle East, and Africa: preliminary results from an ongoing FAO-led
survey. J Wildl Dis 2007 43: S22-S28. Abstract
Full text PDF available at
<http://www.jwildlifedis.org/cgi/repr...Supplement/S22>]

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Wild birds and the epidemiology of avian influenza
--------------------------------------------------
Although wild birds are the recognized source and reservoir for all
subtypes of avian influenza viruses (AIV), the complex interaction
among these diverse host and virus populations has not received
adequate attention. A general concept of AIV epidemiology in wild
birds exists; however, the presence of highly pathogenic avian
influenza (HPAI) H5N1 viruses in wild birds has reinforced the need
for a much more detailed understanding of AIV natural history.
Worldwide, the wild avian reservoirs for AIV are incompletely
defined, even within well-studied groups such as the Anseriformes and
Charadriiformes. This lack of clarity applies not only to avian host
species, but also to the various subtypes of AIV present within these
populations. Even with the extensive number of AIV isolations
previously reported from wild birds, the reservoir species and global
distribution for many of these AIV subtypes are not completely
understood. To date, studies related to AIV epidemiology in wild
birds primarily focused on the agent. To move forward, we need to
apply this same level of scrutiny and detailed understanding to the
natural host populations and the environments they utilize. Research
to date clearly demonstrates that species and population structure
are important in AIV maintenance, transmission, and possibly
long-distance movement. Species-related differences related to
general behavior, spatial and temporal distribution, habitat
utilization, migration behavior, population age structure, and
individual species susceptibility, all potentially influence a
species' role in AIV epidemiology. The unprecedented mortality
associated with HPAI H5N1 infection in wild birds provides a new
window from which to view the potential for exchange of AIV between
wild and domestic birds, and further demonstrates and expands the
varied roles that wild birds may play in AIV epidemiology. These
roles must be clearly defined if we are going understand the full
implications of current HPAI H5N1 virus introduction into the wild
bird populations and most importantly prevent the next one.

[Reference: David E. Stallknecht, Justin D. Brown: Wild birds and the
epidemiology of avian influenza. J Wildl Dis 2007 43: S15-S20. Abstract
Full text PDF available at
<http://www.jwildlifedis.org/cgi/repr...Supplement/S15>]

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Evolution of influenza A viruses in wild birds
----------------------------------------------
Influenza virus surveillance studies in wild bird populations in the
Americas, Europe, and Asia confirmed that wild aquatic birds are the
reservoir for all known influenza A viruses. Phylogenetic analysis
groups the influenza viruses in wild aquatic birds into 2 distinct
superfamilies -- one in the Americas and one in Eurasia. The
separation of viruses into American and Eurasian clades implies that
transmission of HP [highly pathogenic] H5 into the Americas by wild
birds is likely to be a rare event. The rapid evolution of the
Eurasian H5N1 viruses makes them a continued threat to poultry and
humans worldwide.

[Reference: Robert G. Webster, Scott Krauss, Diane Hulse-Post,
Katharine Sturm-Ramirez: Evolution of influenza A viruses in wild
birds. J Wildl Dis 2007 43: S-S6. Abstract
Full text PDF available at
<http://www.jwildlifedis.org/cgi/repr..._Supplement/S1>]

[gsgs]

http://www.pnas.org/cgi/content/abstract/103/51/19368

H5N1-Eintraege in Laender in
Asien: 9/21 durch Gefluegel , 3/21 durch Wandervoegel
Europa: 20/23 durch Wandervoegel
Afrika:2/8 durch Gefluegel , 3/8 durch Wandervoegel