Host-virus interactions underlying mammalian zoonosis of avian influenza viruses in wild bird reservoirs

Abstract

<p>A large and diverse reservoir of avian influenza A viruses (AIVs) is maintained in the environment in wild aquatic bird populations globally. Human cases of AIV infection have generally originated from exposure to infected poultry or swine rather than wild birds. There are numerous examples of zoonotic transmission events of avian-origin IAVs to humans via infected poultry. Examples include subtypes H5N1, H7N9 in 1997 and 2013, respectively. This is partly due to the closer proximity of humans to poultry and swine as a part of farming practices, while direct contact with wild birds is much rarer, although adaptations of AIVs in these hosts may also facilitate human transmissibility. Whilst relatively little is known about the zoonotic potential of AIVs in wild bird reservoirs, it appears that the capacity for mammalian infection and even transmission may not be uncommon. a group of subtype H1N1 AIVs with different capacity for mammalian transmissibility isolated through ongoing wild bird surveillance at Delaware Bay, USA, an important migratory stop-over site, to gain insights into the host-virus interactions underlying zoonotic AIV transmission.</p>