Submitted to: Transboundary and Emerging Diseases
Publication Type: Peer reviewed journal
Publication Acceptance Date: 5/14/2014
Publication Date: 7/23/2014
Publication URL: http://handle.nal.usda.gov/10113/59856
Citation: Ramey, A., Walther, P., Link, P., Poulson, R., Wilcox, B., Newsome, G., Spackman, E., Brown, J., Stallknecht, D. 2014. Optimizing surveillance for South American origin influenza A viruses along the United States Gulf Coast through genomic characterization of isolates from blue-winged teal (Anas discors) . Transboundary and Emerging Diseases. doi: 10.1111/tbed.12244. Interpretive Summary: It is not well known how avian influenza virus moves among ducks between North and South America. Genetic analyses were conducted on avian influenza virus isolates from species of ducks (blue winged teal) which migrate between North and South America to track how the virus moves in the western hemisphere. The virus was genetically distinct from ducks in southern South America (e.g. Argentina) versus viruses from central America and North America which were more closely related. The dissemination of the virus through the Americas is likely affected by geographical features which separate the duck populations, thus keeping the viruses separate. This provides important information on the ecology of avian influenza in natural host species.
Technical Abstract: Relative to research focused on intercontinental viral exchange between Eurasia and North America, less attention has been directed towards understanding the redistribution of influenza A viruses (IAVs) by wild birds between North America and South America. In this study, we genomically characterized 45 viruses isolated from blue-winged teal (Anas discors) along the Texas and Louisiana Gulf Coast during March of 2012 and 2013, coincident with northward migration of this species from Neotropical wintering areas to breeding grounds in the United States and Canada. No evidence of South American lineage genes were detected in IAVs isolated from blue-winged teal supporting restricted viral gene flow between the United States and southern South America. However, it is plausible that blue-winged teal redistribute IAVs between North American breeding grounds and wintering areas throughout the Neotropics, including northern South America, and that viral gene flow is limited by geographical barriers further south (e.g. the Amazon Basin). Surveillance for the introduction of IAVs from Central America and northern South America into the United States may be further optimized through genomic characterization of viruses resulting from coordinated, concurrent sampling efforts targeting blue-wing teal and sympatric species throughout the Neotropics.