Avian Flu in South America or Swine Flu in Argentina

A PEREDA

Foz do Iguacu

Congreso; Congresso Brasileiro de Virología; 2012

Sociedade Brasileira de Virologia

ntil recently, influenza A viruses from wild waterfowl in South America were rarely isolated and/or characterized. To explore the ecology of influenza A viruses in this region, a long-term surveillance program was established in 2006 for resident and migratory water birds in Argentina. We report the characterization of avian influenza viruses mostly isolated from Anseriforms. These isolates corresponds to different HA and NA subtypes. Eight isolates corresponds to H6 subtype, two to H4, one to H13, one to H9, one to H5 and one to H7. Genetic and phylogenetic analysis of the internal gene segments of these viruses revealed a close relationship with influenza viruses from South America that form a unique clade supporting the notion of independent evolution from influenza A viruses in other latitudes. The presence of NS alleles A and B were also identified. Mostly of these isolates also formed unique HA and NA clades separate from North American and Eurasian viruses with the exception of the HA gene of one isolate that was more closely related to the North American lineage, suggesting possible interactions between viruses of North American and South American lineages. Animal studies using H6 isolates suggested that these viruses could replicate and transmit inefficiently in chickens, indicating limited adaptation to poultry. Our results highlight the importance of continued influenza surveillance in wild birds of South America, especially considering the unique evolution of these viruses.