Tularemia above the Treeline: Climate and Rodent Abundance Influences Exposure of a Sentinel Species, the Arctic Fox (<i>Vulpes lagopus</i>), to <i>Francisella tularensis</i>
Kayla Buhler,
Émilie Bouchard,
Stacey Elmore,
Gustaf Samelius,
Jessica Jackson,
Matilde Tomaselli,
Heather Fenton,
Ray Alisauskas,
Emily Jenkins
Affiliations
Kayla Buhler
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
Émilie Bouchard
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
Stacey Elmore
Division of Natural Sciences, University of Maine Fort Kent, 23 University Drive, Fort Kent, MA 04743, USA
Gustaf Samelius
Snow Leopard Trust, 4649 Sunnyside Ave North, Suite 325, Seattle, WA 98103, USA
Jessica Jackson
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
Matilde Tomaselli
Canadian High Arctic Research Station, Polar Knowledge Canada, 1 Uvajuq Road, P.O. Box 2150, Cambridge Bay, NU X0B 0C0, Canada
Heather Fenton
Government of The Northwest Territories, Department of Environment and Natural Resources, 5th Floor Scotiabank Centre, P.O. Box 1320, Yellowknife, NT X1A 2P9, Canada
Ray Alisauskas
Prairie and Northern Wildlife Research Centre, Wildlife Research Division, Environment and Climate Change Canada, 115 Perimeter Road, Saskatoon, SK S7N 0X4, Canada
Emily Jenkins
Department of Veterinary Microbiology, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK S7N 5B4, Canada
Tularemia is a zoonotic disease found throughout most of the northern hemisphere that may experience range expansion with warming temperatures. Rodents and lagomorphs are reservoirs for the disease, and outbreaks of tularemia often follow peaks in their abundance. As small mammals dominate the diet of arctic foxes (Vulpes lagopus), we determined whether they may serve as sentinels by identifying antibodies in live-captured and harvested foxes from northern Canada. Overall seroprevalence was 2% (CI95 1–2%) in 176 foxes harvested in 2018–2019 compared to 17% (CI95 12–22%) of 230 foxes captured live in 2011–2021. Prevalence was at an all-time high in 2018, following a peak in vole abundance in 2017. Antibodies were identified in fox pups born in 2018 and 2019, suggesting that F. tularensis was actively transmitted during the summers. High precipitation during the summer, increased snow cover and colder temperatures in May, and a higher abundance of voles were all associated with increased seroprevalence in live-captured foxes. Thus, exposure to F. tularensis is largely mediated through climate and rodent populations in the Canadian Arctic, and arctic foxes are useful sentinels for F. tularensis in northern ecosystems. Further studies should investigate whether infection impacts arctic fox survival and reproductive success in the circumpolar North.
