Vulnerabilities to the risks of changes in infectious disease transmission caused by climate change: a modelling study

Abstract

BackgroundThe geographic range, seasonality, and incidence of many infectious diseases might change with climate change. Yet, most models of these effects have not been able to account for the exacerbating or mitigating effects of socioeconomic variables. Vulnerability is understood to be the propensity to be adversely affected by a given cause. We assessed vulnerabilities and how these affect the relations between infectious disease transmission and climate change. MethodsWe developed vulnerability indices at the subnational level for 2035, and 2055. We assessed various datasets for their inclusion in a conceptual framework of vulnerability (consisting of impact and adaptive capacity). We plotted the projected change in absolute precipitation and temperature for European regions and used it as a proxy for change in temperature-sensitive infectious disease incidence. We used climate change projections of European-wide monthly means for daily temperature (Tmin and Tmax in °C) and daily precipitation (in mm) for 2035 and 2055, to map possible changes in infectious disease risk. These projections were based on a multimodel ensemble with three emission scenarios (A1b, A2, B1) and four earth system models (ECHAM5, MIROC3, CNRM, CSIRO3) and downscaled to 1 km resolution. We used a composite adaptive capacity indicator to assess vulnerability on the basis of regional adaptive capacity index developed by the ESPON project. Final vulnerability indices combined the impact and adaptive capacity indices, plotted via ArcGIS to EU regions for 2035 and 2055 and ranked into quintiles. We assessed the key factors driving the impact and vulnerability indices with a Spearman rank correlation test. FindingsMany areas in southeast England, Norway, Denmark, Sweden, and southern Germany had lower rankings for vulnerabilities than for projected impacts, showing a protective effect of strong adaptive capacity. Conversely, regions in Romania, Bulgaria, Greece, and southern Italy were in higher vulnerability index quintiles than impact index quintiles. Precipitation had more of an effect than temperature in driving the impact indices, but this was regionally variable. InterpretationSome European regions probably require additional investment to develop strategies to adapt to climate change for public health. Investing generally in factors that strengthen adaptive capacity could lower vulnerabilities. Presently, modelling vulnerabilities to climate change has many uncertainties and limitations. Systematic collection and analysis is needed of the links between environmental, socioeconomic, demographic, and epidemiologic variables to better understand the risk to health presented by climate change. FundingEuropean Centre for Disease Prevention and Control.