Mallards and Highly Pathogenic Avian Influenza Ancestral Viruses, Northern Europe

摘要

Outbreaks of highly pathogenic avian influenza (HPAI),which originate in poultry upon transmission of low patho-genic viruses from wild birds, have occurred relatively fre-quently in the last decade. During our ongoing surveillancestudies in wild birds, we isolated several influenza A virus-es of hemagglutinin subtype H5 and H7 that contain vari-ous neuraminidase subtypes. For each of the recorded H5and H7 HPAI outbreaks in Europe since 1997, our collec-tion contained closely related virus isolates recovered fromwild birds, as determined by sequencing and phylogeneticanalyses of the hemagglutinin gene and antigenic charac-terization of the hemagglutinin glycoprotein. The minorgenetic and antigenic diversity between the viruses recov-ered from wild birds and those causing HPAI outbreaksindicates that influenza A virus surveillance studies in wildbirds can help generate prototypic vaccine candidates anddesign and evaluate diagnostic tests, before outbreaksoccur in animals and humans