Avian influenza virus in water: infectivity is dependent on pH, salinity and temperature.

Wild birds in the Orders Anseriformes and Charadriiformes are the natural reservoir for avian influenza (AI) viruses. Transmission within these aquatic bird populations occurs through an indirect fecal-oral route involving contaminated water on shared aquatic habitats. In order to better understand the influence that aquatic environments exert on AI transmission and maintenance in the wild-bird reservoir system, we determined the duration of persistence for 12 wild-bird origin AI viruses under natural ranges of pH, salinity, and temperature.

Susceptibility of wood ducks to H5N1 highly pathogenic avian influenza virus.

Since 2002, H5N1 highly pathogenic avian influenza (HPAI) viruses have caused mortality in numerous species of wild birds; this is atypical for avian influenza virus (AIV) infections in these avian species, especially for species within the order Anseriformes. Although these infections document the susceptibility of wild birds to H5N1 HPAI viruses and the spillover of these viruses from infected domestic birds to wild birds, it is unknown whether H5N1 HPAI viruses can persist in free-living avian populations. In a previous study, we established that wood ducks (Aix sponsa) are highly susceptible to infection with H5N1 HPAI viruses.