Why are Svalbard Arctic foxes Brucella spp. seronegative?

• Published in: Polar Research
• Main Authors: Nymo, Ingebjørg H., Fuglei, Eva, Mørk, Torill, Breines, Eva M., Holmgren, Karin, Davidson, Rebecca, Tryland, Morten
• Format: Article in Journal/Newspaper
• Language: English
• Published: Norwegian Polar Institute 2022
• Subjects: Infection; serology; smooth Brucella; s-Brucella; Vulpes lagopus; epizootiology; Arctic; Svalbard; Arctic Fox; Iceland; Polar Research; Ursus maritimus; Alaska
• Online Access: https://polarresearch.net/index.php/polar/article/view/7867; https://doi.org/10.33265/polar.v41.7867

Arctic foxes (Vulpes lagopus) are susceptible to smoothBrucella(s-Brucella) infection and may be exposed to such bacteria through the consumption of infected marine mammals, as implied by the finding of s-Brucellaantibodies in polar bears (Ursus maritimus). Arctic foxes in Svalbard have not previously been investigated for s-Brucellaantibodies, but such antibodies have been detected in Arctic foxes in Iceland, Alaska (USA) and Russia. We investigated blood from Svalbard Arctic foxes for s-Brucellaantibodies using an indirect enzyme-linked immunosorbent assay (iELISA). The animals (0–13 years old) were either caught by fur trappers (1995–2003,n= 403) or found dead (1995 and 2003,n= 3). No seropositive animals were detected. Morbidity and mortality due to the infection cannot be ruled out. However, no known, large disease outbreaks of unknown aetiology have been reported. Furthermore, it is unlikely that the Svalbard Arctic fox is resistant to infection as Arctic foxes from other populations are susceptible, and there is circumpolar connectivity between populations. The discrepancy between the findings in Iceland and Svalbard is surprising as both populations are on islands with no known local sources of exposure to s-Brucellaother than marine mammals. However, our negative findings suggest that marine mammals may not be a major source of infection for this species. Comparative investigations are needed in order to draw conclusions regarding the epizootiology of s-Brucellain Arctic foxes in Svalbard and Iceland.