Avian Influenza Virus Prevalence in Migratory Waterfowl in the United States, 2007–2009

• Published in: Avian Diseases
• Main Authors: Scott R. Groepper, Thomas J. DeLiberto, Mark P. Vrtiska, Kerri Pedersen, Seth R. Swafford, Scott E. Hygnstrom
• Format: Text
• Language: English
• Published: American Association of Avian Pathologists 2014
• Subjects: Alta; Pacific; Anas acuta; Anas clypeata; Northern Shoveler; Shoveler
• Online Access: https://doi.org/10.1637/10849-042214-Reg.1

We analyzed 155,535 samples collected for surveillance of avian influenza viruses (AIVs), in the United States from 2007 to 2009, from migratory waterfowl (ducks, geese, and swans). The goal was to elucidate patterns of prevalence by flyway and functional groups to determine targets for future surveillance. Apparent prevalence of AIV was highest in the Pacific Flyway in 2007–2008 (14.2% and 14.1%, respectively), in the Mississippi Flyway in 2009 (16.8%), and lowest each year in the Atlantic Flyway (range, 7.3%–8.9%). Dabbling ducks had higher apparent prevalence of AIV (12.8%–18.8%) than diving ducks (3.9%–6.0%) or geese and swans (3.6%–3.9%). We observed highest apparent prevalence in hatch-year waterfowl (15.6%–18.9%). We further analyzed 117,738 of the 155,535 samples to test the hypothesis mallard (Anas platyrhynchos) had highest prevalence of AIV. We compared apparent prevalence and odds ratios for seven species of ducks and one species of goose commonly collected across the United States. Mallards had highest apparent prevalence (15%–26%) in half of comparisons made, whereas American green-winged teal (Anas creeca, 12%–13%), blue-winged teal (Anas discors, 13%–23%), northern pintail (Anas acuta, 16%–22%), or northern shoveler (Anas clypeata, 15%) had higher apparent prevalence in the remaining comparisons. The results of our research can be used to tailor future surveillance that targets flyways, functional groups, and species with the highest probability of detecting AIV.Prevalencia del virus de la influenza aviar en aves acuáticas migratorias en los Estados Unidos, 2007–2009.Se analizaron 155,535 muestras recolectadas para la vigilancia de los virus de influenza aviar (AIV), en los Estados Unidos desde el año 2007 al año 2009, procedentes de aves acuáticas migratorias (patos, gansos y cisnes). El objetivo fue determinar los patrones de prevalencia por vías migratorias y por grupos funcionales para determinar los objetivos de vigilancia en el futuro. La prevalencia aparente de influenza aviar fue más alta ...