Yersinia pestis is a gram-negative bacterium, primarily transmitted via flea bite, that causes plague in numerous mammal species. While rare, humans in the United States (US) can suffer major pathology and plague is of conservation concern for endangered mammal species. Surveillance in wildlife can shed light on pathogen persistence and epizootic events; however, wildlife surveillance is often characterized by uneven sampling effort and non-random sampling strategies. Therefore, the utility of using wildlife surveillance data to inform our understanding of plague ecology has been limited. Zoonotic diseases are influenced by climate variables because climate determines the ecological niche of hosts and interactions between hosts, vector, and pathogen. Because of their high tolerance to plague pathology paired with their ecological interactions with rodent species, Canis latrans (coyotes) are used as wildlife sentinel species for plague. A kernel density based ecological niche model was conducted using ~29,000 locations of coyotes tested for plague antibodies 2000 – 2015 and PRISM 30-Year Average Normals. A Monte Carlo based statistical comparison of spatial densities was used to detect significantly different habitat types where plague was and was not detected in coyotes. These habitats were then identified in the US.
Results/Conclusions
Habitat types where plague was significantly more likely to be detected in coyotes compared to habitat types were plague was not detected in coyotes include cooler, semi-arid areas across the Western US such as the leeward side of high mountain ranges and high-plateaued regions the Rocky Mountains. The Yersinia pestis niche in coyotes was identified in areas where coyotes were not sampled or may not be observed in high frequency because of host habitat preferences. Also, due to the nature of Canis latrans behavior and limits of sampling resources, coyotes are collected and tested by US government agencies unevenly across the US. Coyotes are sampled by these agencies across known coyote habitats when compared to ~14,000 coyote observations from museum collections, with under sampling occurring in high precipitation areas such as the windward side of the Cascade Range and high alpine areas of the Rocky Mountains. Future research will explore data- and modeling-based approaches to incorporate these findings. The kernel density based plague niche is likely a conservative estimate of potential plague habitat in the US. These results can be used to strategize which coyotes to test for plague, potentially from undersampled areas.