Dynamics and persistence of rabies in the Canadian Arctic

Rabies persists throughout the circumpolar Arctic and poses an ongoing threat to the health of people and domestic animals in the north. The Arctic fox (Vulpes lagopus) is the primary reservoir for rabies in the Arctic, and... [ view full abstract ]

Rabies persists throughout the circumpolar Arctic and poses an ongoing threat to the health of people and domestic animals in the north. The Arctic fox (Vulpes lagopus) is the primary reservoir for rabies in the Arctic, and rabid foxes may attack and infect domestic dogs, which in turn may bite and infect people. Each year in the communities of the Canadian Arctic, contact with rabid foxes and cases of dog aggression result in expensive interventions to prevent possible rabies. Little is known about the epidemiology of rabies in the Arctic fox and, more specifically, how dog and human exposure may be affected by rapid anthropogenic changes occurring in this region due to resource development and climate warming.
The objective of this study was to use spatial and temporal disease modelling to explore the complex dynamics of rabies risk exposure at the interface between wildlife, domestic animals and people in northern Canada. Specifically, we developed a multi-species dynamic compartmental model and a spatially-explicit agent-based simulation model for Arctic rabies in order to: 1) identify factors underlying the transmission and persistence of rabies in Arctic foxes, 2) explore how rabies dynamics may be affected by anthropogenic changes (climate warming and northern development) occurring in Arctic ecosystems, and 3) provide new tools to predict the timing and spread of outbreaks and explore possible control strategies.
Modelling results suggest that increasing contact between arctic and red foxes synchronizes rabies outbreaks between populations while increasing outbreak intensity, and that multi-annual population cycles of fox prey (lemmings) make rabies outbreaks less regular, less frequent, but more intense.
This study provides the first models of wildlife rabies epidemiology in the Arctic, demonstrating the importance of host ecology and highlighting several important potential impacts of climate change on this system with consequences for animal and public health.