Climate-change Effects on the Geographic Distribution of Infectious Diseases in the Arctic

Tomas Thierfelder

Swedish University of Agricultural Sciences SLU, Tomas.Thierfelder@slu.se

Introduction: Climate change is considered to have a significant impact on the epidemiology of Arctic infectious diseases, that threatens Arctic societies by terms of socio-economy, culture, health, welfare, security, animal husbandry, and food supply (etc.). With arctic societies being generally dependent on husbandry animals, the erosion of animal welfare introduced with emerging zoonotic diseases adds to the effects of human exposure, where the resulting dynamic scenario requires a holistic OneHealth study-approach.

Methods: The authorities that administer national programs of infectious diseases control have been engaged in the acquirement of diseases data covering Denmark/Greenland, Iceland, Norway, Sweden, Finland and Russia/Siberia through the past 30-year climate reference period, regarding incidences of anthrax, borreliosis, brucellosis, cryptosporidiosis, leptospirosis, hantavirus infection, Q-fever, tick born encephalitis, and tularaemia. These data were supplemented with satellite-sensed climate and landscape data covering the same reference period of time with approximately 35 standard variables ranging from different temperature cumulations, via snow-cover duration, to chlorophyll density. When combined, climate and landscape data were down-scaled to characterise administrative diseases report districts (basically at county-level) and used to statistically infer the observed spatiotemporal variation of diseases incidences. The selection of diseases and climate variables was made via a process of expert review, and all diseases data were anonymised.

Results: Preliminary studies indicate strong climate sensitivity regarding some diseases, and no sensitivity regarding others. With climate sensitivity indicating a potential of diseases migrating with landscape effects of climate change, and where this potential is much regulated by the ecological characteristics of the vector and reservoir organisms that carry diseases pathogens through the landscape, climate sensitive infections (CSI’s) may hence be identified and further assessed with respect to societal effects and adequate counter-measures. In addition, the average incidence scenarios that cover the 30-year IPCC climate reference period define a “diseases climate” from western Greenland to the Russian Pacific.

Discussion: By geographically correlating the spread of climate and landscape characteristics with CSI incidences, future CSI scenarios may be predicted as a function of the IPCC climate projections. Such CSI projections constitute invaluable decision support in the process of strengthening the climate resilience of Arctic societies and cultures.