Demographic and Spatiotemporal Patterns of Avian Influenza Infection at the Continental Scale, and in Relation to Annual Life Cycle of a Migratory Host

Authors

Rodolfo Nallar, University of Saskatchewan
Zsuzsanna Papp, Environment Canada, Science & Technology Branch, Saskatoon, Saskatchewan, Canada
Tasha Epp, University of Saskatchewan
Frederick A. Leighton, University of Saskatchewan
Seth R. Swafford, United States Department of Interior, US Fish and Wildlife Service, Yazoo City, Mississippi
Thomas J. DeLiberto, USDA/APHIS/WS National Wildlife Research CenterFollow
Robert J. Dusek, United States Geological Survey, National Wildlife Health Center
Hon S. Ip, United States Geological Survey, National Wildlife Health Center
Jeffrey Hall, United States Geological Survey, National Wildlife Health CenterFollow
Yohannes Berhane, National Centre for Foreign Animal Disease, Canadian Food Inspection Agency, Winnipeg, Manitoba, CanadaFollow
Samantha E.J. Gibbs, United States Fish and Wildlife Service, Division of Migratory Bird Management, Laurel, Maryland
Catherine Soos, University of SaskatchewanFollow

Date of this Version

2015

Citation

Nallar R, Papp Z, Epp T, Leighton FA, Swafford SR, DeLiberto TJ, et al. (2015) Demographic and Spatiotemporal Patterns of Avian Influenza Infection at the Continental Scale, and in Relation to Annual Life Cycle of a Migratory Host. PLoS ONE 10(6): e0130662.

Comments

U.S. Government Work

Abstract

Since the spread of highly pathogenic avian influenza (HPAI) H5N1 in the eastern hemisphere, numerous surveillance programs and studies have been undertaken to detect the occurrence, distribution, or spread of avian influenza viruses (AIV) in wild bird populations worldwide. To identify demographic determinants and spatiotemporal patterns of AIV infection in long distance migratory waterfowl in North America, we fitted generalized linear models with binominal distribution to analyze results from 13,574 blue-winged teal (Anas discors, BWTE) sampled in 2007 to 2010 year round during AIV surveillance programs in Canada and the United States. Our analyses revealed that during late summer staging (July-August) and fall migration (September-October), hatch year (HY) birds were more likely to be infected than after hatch year (AHY) birds, however there was no difference between age categories for the remainder of the year (winter, spring migration, and breeding period), likely due to maturing immune systems and newly acquired immunity of HY birds. Probability of infection increased non-linearly with latitude, and was highest in late summer prior to fall migration when densities of birds and the proportion of susceptible HY birds in the population are highest. Birds in the Central and Mississippi flyways were more likely to be infected compared to those in the Atlantic flyway. Seasonal cycles and spatial variation of AIV infection were largely driven by the dynamics of AIV infection in HY birds, which had more prominent cycles and spatial variation in infection compared to AHY birds. Our results demonstrate demographic as well as seasonal, latitudinal and flyway trends across Canada and the US, while illustrating the importance of migratory host life cycle and age in driving cyclical patterns of prevalence.