Spatial Dynamics of Human-Origin H1 Influenza A Virus in North American Swine

PLoS Pathogens

Tommy Tsan-Yuk Lam¹  Philippe Lemey²  Marc A. Suchard³  Andrew Rambaut⁴  Martha I. Nelson⁴  Cécile Viboud⁴  Yi Tan⁴  Marie Gramer⁴  Edward C. Holmes⁵  Susan Detmer⁶  Amy Vincent⁷ 

[1] Department of Biology, The Pennsylvania State University, University Park, Pennsylvania, United States of America;Department of Microbiology and Immunology, Katholieke Universiteit Leuven, Leuven, Belgium;Departments of Biomathematics and Human Genetics, David Geffen School of Medicine at UCLA, and Department of Biostatistics, UCLA School of Public Health, Los Angeles, California, United States of America;Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, Maryland, United States of America;Institute of Evolutionary Biology, University of Edinburgh, Ashworth Laboratories, Edinburgh, United Kingdom;The University of Minnesota Veterinary Diagnostic Laboratory, St. Paul, Minnesota, United States of America;Virus and Prion Diseases of Livestock Research Unit, National Animal Disease Center, USDA-ARS, Ames, Iowa, United States of America

关键词: Swine;    Influenza viruses;    Swine influenza;    H1N1;    Phylogenetics;    Phylogeography;    Influenza A virus;    United States;   

DOI  :  10.1371/journal.ppat.1002077

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The emergence and rapid global spread of the swine-origin H1N1/09 pandemic influenza A virus in humans underscores the importance of swine populations as reservoirs for genetically diverse influenza viruses with the potential to infect humans. However, despite their significance for animal and human health, relatively little is known about the phylogeography of swine influenza viruses in the United States. This study utilizes an expansive data set of hemagglutinin (HA1) sequences (n = 1516) from swine influenza viruses collected in North America during the period 2003–2010. With these data we investigate the spatial dissemination of a novel influenza virus of the H1 subtype that was introduced into the North American swine population via two separate human-to-swine transmission events around 2003. Bayesian phylogeographic analysis reveals that the spatial dissemination of this influenza virus in the US swine population follows long-distance swine movements from the Southern US to the Midwest, a corn-rich commercial center that imports millions of swine annually. Hence, multiple genetically diverse influenza viruses are introduced and co-circulate in the Midwest, providing the opportunity for genomic reassortment. Overall, the Midwest serves primarily as an ecological sink for swine influenza in the US, with sources of virus genetic diversity instead located in the Southeast (mainly North Carolina) and South-central (mainly Oklahoma) regions. Understanding the importance of long-distance pig transportation in the evolution and spatial dissemination of the influenza virus in swine may inform future strategies for the surveillance and control of influenza, and perhaps other swine pathogens.

【 授权许可】

CC BY