With Climate Week coming up and the topic of climate change on everyone’s mind at the moment, Acta Veterinaria Scandinavica has published a timely review by Dr Karsten Hueffer et al. on the changing interactions between pathogens and their hosts in the Arctic to add further food for thought to this important issue.
    
The arctic environment is one of large seasonal changes in temperature and amount of daylight, resulting in the animals that live there becoming highly specialized and adapted to their very specific environment. The seasonal changes of the ice cover through periods of warming and freezing are highly synchronized with the arctic temperatures and the amount of daylight throughout the year. As the climate warms in the Arctic these major cues in seasonal rhythms will change and uncouple, leading to earlier spring melt and less sea ice and exerting pressure on these animals to adapt quickly to the new surroundings. These changes could have drastic consequences on the behaviour of arctic animals and the interactions between them and their pathogens.

With the temperature set to rise, it is predicted that infectious disease agents will be able to move into the northern habitats which were previously too cold for them to survive in. The decrease in sea ice is also likely to increase maritime traffic traveling into the Arctic to extract resources, bringing the highly specialised and sensitive arctic animals into more frequent contact with humans and domestic animals, and introducing pathogens along with this.  

Hueffer et al. discuss the effects that these changes can have on host-pathogen interactions amongst different arctic animals, using several studies on different species to illustrate these effects and how they may change in future. This is an interesting and topical article and helps to explain the current situation in the Arctic, illustrating the amount of research there is still to be done on the threats facing these animals in their fragile ecosystem.