Cross-seasonal patterns of avian influenza virus in breeding and wintering migratory birds: a flyway perspective

Vector-Borne and Zoonotic Diseases
By: , and 



The spread of avian influenza viruses (AIV) in nature is intrinsically linked with the movements of wild birds. Wild birds are the reservoirs for the virus and their migration may facilitate the circulation of AIV between breeding and wintering areas. This cycle of dispersal has become widely accepted; however, there are few AIV studies that present cross-seasonal information. A flyway perspective is critical for understanding how wild birds contribute to the persistence of AIV over large spatial and temporal scales, with implications for how to focus surveillance efforts and identify risks to public health. This study characterized spatio-temporal infection patterns in 10,389 waterfowl at two important locations within the Pacific Flyway--breeding sites in Interior Alaska and wintering sites in California's Central Valley during 2007-2009. Among the dabbling ducks sampled, the northern shoveler (Anas clypeata) had the highest prevalence of AIV at both breeding (32.2%) and wintering (5.2%) locations. This is in contrast to surveillance studies conducted in other flyways that have identified the mallard (Anas platyrhynchos) and northern pintail (Anas acuta) as hosts with the highest prevalence. A higher diversity of AIV subtypes was apparent at wintering (n=42) compared with breeding sites (n=17), with evidence of mixed infections at both locations. Our study suggests that wintering sites may act as an important mixing bowl for transmission among waterfowl in a flyway, creating opportunities for the reassortment of the virus. Our findings shed light on how the dynamics of AIV infection of wild bird populations can vary between the two ends of a migratory flyway.
Publication type Article
Publication Subtype Journal Article
Title Cross-seasonal patterns of avian influenza virus in breeding and wintering migratory birds: a flyway perspective
Series title Vector-Borne and Zoonotic Diseases
DOI 10.1089/vbz.2010.0246
Volume 12
Issue 3
Year Published 2012
Language English
Publisher Society for Zoonotic Ecology and Epidemiology
Publisher location Larchmont, NY
Contributing office(s) Western Ecological Research Center
Description 11 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Vector-Borne and Zoonotic Diseases
First page 243
Last page 253
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