Berl Munch Tierarztl
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Berl Munch Tierarztl · Nov 2009
Review[Bird populations--hatching grounds of pandemic influenza viruses?].
Aquatic wild birds constitute the natural reservoir of influenza A viruses. Under appropriate selection pressure these viruses display a remarkable genetic flexibility which is based on their high mutation rate. At least 16 subtypes of the viral hemagglutinin glycoprotein (HA) und 9 of the viral neuraminidase (NA) are distinguishable as a result of natural evolution. ⋯ Subtype H5 and H7 viruses which are maintained in the natural reservoir hosts, in contrast, are of low pathogenicity (LPAI) and harbour monobasic HA cleavage sites restricting their tissue tropism to epithelia of the respiratory and gastronintestinal tracts. This context forms the basis of all legal measures targeting the monitoring, prevention and eradication of HPAIV and LPAIV of subtypes H5 and H7 in poultry. Results of such measures in Germany in 2008 are presented and discussed.