Drivers Shaping Spillover of Aleutian Mink Disease Virus Introduced With American Mink Among Native Mustelids

Invasive alien species pose a major threat to ecosystems by outcompeting native species for resources, altering habitats, enabling potential genetic hybridisation and introducing pathogens into the environment. An understanding of the factors that determine virus transfer between invasive and native species is crucial to the mitigation of the negative impact of the pathogens introduced. This study presents a comprehensive analysis of factors influencing Aleutian mink disease virus (AMDV) infection in native mustelids in Poland, following its introduction by feral American mink. AMDV seroprevalence in American mink varied spatially from 0 in the central and southern regions to 0.8 in the northern regions. Antibodies to AMDV were detected in all six studied mustelids, including a novel finding in weasels. AMDV seroprevalence in other mustelids correlated positively with its occurrence in American mink, and reached 0.54 in areas with the highest mink AMDV seroprevalence. Furthermore, in native mustelids, more closely phylogenetically related to mink, AMDV seroprevalence was higher (0.68 in polecats and weasels) compared to more distantly related species (0.37 in badgers). Over the 27-year study period, AMDV seroprevalence in mustelids has increased from 0.04 to 0.60, despite a decline in seroprevalence in feral mink in subsequent years. These findings suggest that the spread of viral infections as a result of the introduction of invasive species could affect mustelid species and may intensify over time.