Authors: Jonathon D. Gass Jr.
1,†, Robert J. Dusek
2, Jeffrey S. Hall
2, Gunnar Thor Hallgrimsson
3, Halldór Pálmar Halldórsson
4, Solvi Runar Vignisson
4,5, Sunna Bjork Ragnarsdottir
6, 7, Jón Einar Jónsson
8, Scott Krauss
9, Sook-San Wong
9,ŧ,
Xiu-Feng Wan
10, 11, 12, 13, Sadia Akter
10, 11, 12, 13,*, Srinand Sreevatsan
14, Nídia S. Trovão
15, Felicia B. Nutter
1, Jonathan A. Runstadler
1, Nichola J. Hill
1,16 1 Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine, Tufts University
2 U.S. Geological Survey, National Wildlife Health Center
3 Institute of Biology, University of Iceland
4 University of Iceland’s Research Centre in Suðurnes
5 Suðurnes Science and Learning Center
6 Icelandic Institute of Natural History
7 The Southwest Iceland Nature Research Centre
8 University of Iceland's Research Center at Snæfellsnes
9 Department of Infectious Diseases, St. Jude Children’s Research Hospital
10 Center for Influenza and Emerging Infectious Diseases (CIEID), University of Missouri, Columbia
11 Department of Molecular Microbiology and Immunology, University of Missouri, Columbia
12 Bond Life Sciences Center, University of Missouri, Columbia
13 Department of Electronic Engineering and Computer Science, University of Missouri, Columbia
14 College of Veterinary Medicine, Michigan State University
15 Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health
16 Department of Biology, University of Massachusetts, Boston
† Corresponding author
ŧ Present address: State-Key Laboratory of Respiratory Diseases, Guangzhou Medical University and School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong * Present address: Department of Molecular Microbiology, Washington University School of Medicine in St. Louis
Abstract
Influenza A viruses (IAV) circulate endemically among many wild aquatic bird populations that seasonally migrate between wintering grounds in southern latitudes to breeding ranges along the perimeter of the circumpolar arctic. Arctic and subarctic zones are hypothesized to serve as ecologic drivers of the intercontinental movement and reassortment of IAVs due to high densities of disparate populations of long distance migratory and native bird species present during breeding seasons. Iceland is a staging ground that connects the East Atlantic and North Atlantic American flyways, providing a unique study system for characterizing viral flow between eastern and western hemispheres. Using Bayesian phylodynamic analyses, we sought to evaluate the viral connectivity of Iceland to proximal regions and how inter-species transmission and reassortment dynamics in this region influence the geographic spread of low and highly pathogenic IAVs. Findings demonstrate that IAV movement in the arctic and subarctic reflects wild bird migration around the perimeter of the circumpolar north, favoring short-distance flights between proximal regions rather than long distance flights over the polar interior. Iceland connects virus movement between mainland Europe and North America, consistent with the westward migration of wild birds from mainland Europe to Northeastern Canada and Greenland. Though virus diffusion rates were similar among avian taxonomic groups in Iceland, gulls play an outsized role as sinks of IAVs from other avian hosts prior to onward migration. These data identify patterns of virus movement in northern latitudes and inform future surveillance strategies related to seasonal and emergent IAVs with potential public health concern.
Keywords: Influenza A virus, Iceland, wild birds, phylodynamics, transmission, subarctic