Avian Influenza (H5N1) Virus in Waterfowl and Chickens, Central China

Abstract

In 2004, 3 and 4 strains of avian influenza virus (subtype H5N1) were isolated from waterfowl and chickens, respectively, in central People’s Republic of China. Viral replication and pathogenicity were evaluated in chickens, quails, pigeons, and mice. We analyzed the sequences of the hemagglutinin and neuraminidase genes of the isolates and found broad diversity among them.

A current review of avian influenza in pigeons and doves (Columbidae)

“…Contact pigeons: 5/6 bELISA positive and 0/6 HI positive. studies conducted by Klopfleisch et al (2006), Yu et al (2007) and Hayashi et al (2011a). Hayashi and co-workers conceded that that the reason for the high mortalities observed (5/14 of pigeons dying within a two-week period) were probably due to environmental stress and not AIV infection, since two of these mortalities were in the sham-inoculated group.…”

“…Variations in severity of infection and duration were observed depending on the strain and inoculum dose (Yu et al, 2007;Jia et al, 2008;Brown et al, 2009;Smietanka et al, 2011;Phonaknguen et al, 2013). In contrast to the sporadic distribution and variability in severity of macro and microscopic lesions and virus detection in the aforementioned organ systems, most studies found that non-suppurative encephalitis is a characteristic finding in pigeons infected with the HPAI viruses, suggesting that the central nervous system in pigeons is frequently affected by this virus, even with asymptomatic infection (Yamamoto et al, 2012;Brown et al, 2009;Klopfleisch et al, 2006;Werner et al, 2007;Jia et al, 2008;Smietanka et al, 2011;Hayashi et al, 2011a;Phonaknguen et al, 2013).…”

Victims and Vectors: Highly Pathogenic Avian Influenza H5N1 and the Ecology of Wild Birds

“…Wet markets have been identified as a primary source of HPAI H5N1 in China (Liu et al, 2003;Wang et al, 2006;Yu et al, 2007) and Thailand (Amonsin et al, 2008) and were the original site of the 1997 outbreak in Hong Kong (Shortridge et al, 1998). Wet markets typically house multiple bird species drawn from populations in different geographic regions together at high densities, which coupled with the daily introduction of new birds is conducive to the exchange of AIV subtypes between hosts (Webster, 2004;Cardona et al, 2009).…”

“…Some wild bird taxa such as corvids, sparrows, and pigeons tolerate human-modified environments and show resistance against HPAI viruses (Perkins and Swayne, 2003). Challenge studies with HPAI H5N1 revealed that pigeons show few clinical symptoms of the virus upon infection (Boon et al, 2007;Yu et al, 2007), and thus, may act as 'silent carriers' within human-modified environments. In rural landscapes, wild birds such as egrets are ubiquitous along canals and agricultural ponds and may also serve as a bridge between domestic and wild birds.…”

Effect on Virulence and Pathogenicity of H5N1 Influenza A Virus through Truncations of NS1 eIF4GI Binding Domain

“…The H5N1 virus A/chicken/Hubei/327/2004 (CKDW/04) was isolated in central China during the outbreak of the highly pathogenic H5N1 avian influenza virus (AIV) in the spring of 2004. Pathogenesis tests in BALB/c mice and specific-pathogen free (SPF) chickens indicated that CKDW/04 was highly pathogenic to mice and had a chicken intravenous pathogenicity index (IVPI) of 3.0 [20]. The sequence accession numbers of HA, NA, and NS genes from CKDW/04 are AY684706, AY684708, and AY684710, respectively.…”