Avian Influenza in Poultry

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Avian influenza is a viral disease affecting the respiratory, digestive and/or nervous system of many species of birds. Avian influenza virus infection can occur in most, if not all, species of birds, both domestic and wild. Influenza viruses vary widely in their ability to cause disease (pathogenicity) and their ability to spread among birds. Wild species of birds usually do not develop clinical disease, but some influenza viruses cause severe illness or death in chickens, turkeys and guinea fowl.

http://edis.ifas.ufl.edu/pdffiles/PS/PS03200.pdf

[Sarcelle]

Implications of wildlife trade on the movement of avian
influenza and other infectious diseases
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The global trade in wildlife provides disease transmission mechanisms
that not only result in human disease outbreaks, but also threaten
livestock, international trade, rural livelihoods, native wildlife
populations, and the health of ecosystems. Global movement of animals
for the pet trade is estimated at some 350 million live animals,
worth approximately USD 20 billion per year. Approximately
one-quarter of this trade is thought to be illegal, hence not
inspected or tested. Disease outbreaks resulting from trade in
wildlife have caused hundreds of billions of dollars of economic
damage globally. Rather than attempting to eradicate pathogens or the
wild species that may harbor them, a practical approach would include
decreasing the contact rate among species, including humans, at the
interface created by wildlife trade. Wild animals are captured,
transported, and sold either live or dead and commingled throughout
the process in a system of scale-free networks with major hubs rather
than random or evenly distributed supply systems. As focal points for
distribution and sales, the hubs provide control opportunities to
maximize the effects of regulatory efforts as demonstrated with
domestic animal trading systems (processing plants and wholesale and
retail markets, for example). Focusing efforts at markets to
regulate, reduce, or in some cases, eliminate the commercial trade in
wildlife could provide a cost-effective approach to decrease the
risks for disease in humans, domestic animals, wildlife, and ecosystems.

[Reference: William B. Karesh, Robert A. Cook, Martin Gilbert, James
Newcomb: Implications of wildlife trade on the movement of avian
influenza and other infectious diseases. J Wildl Dis 2007 43: S55-S59. Abstract
Full text PDF available at
<http://www.jwildlifedis.org/cgi/repr...Supplement/S55>]