Journal article
Predicting and mapping human risk of exposure to Ixodes ricinus nymphs using climatic and environmental data, Denmark, Norway and Sweden, 2016
Epidemiology, Division for Diagnostics & Scientific Advice, National Veterinary Institute, Technical University of Denmark1
National Veterinary Institute, Technical University of Denmark2
Norwegian Institute of Public Health3
Norwegian University of Life Sciences4
University of Agder5
Swedish University of Agricultural Sciences6
Department of Applied Mathematics and Computer Science, Technical University of Denmark7
Statistics and Data Analysis, Department of Applied Mathematics and Computer Science, Technical University of Denmark8
Background: Tick-borne diseases have become increasingly common in recent decades and present a health problem in many parts of Europe. Control and prevention of these diseases require a better understanding of vector distribution. Aim: Our aim was to create a model able to predict the distribution of Ixodes ricinus nymphs in southern Scandinavia and to assess how this relates to risk of human exposure.
Methods: We measured the presence of I. ricinus tick nymphs at 159 stratified random lowland forest and meadow sites in Denmark, Norway and Sweden by dragging 400 m transects from August to September 2016, representing a total distance of 63.6 km. Using climate and remote sensing environmental data and boosted regression tree modelling, we predicted the overall spatial distribution of I. ricinus nymphs in Scandinavia.
To assess the potential public health impact, we combined the predicted tick distribution with human density maps to determine the proportion of people at risk. Results: Our model predicted the spatial distribution of I. ricinus nymphs with a sensitivity of 91% and a specificity of 60%. Temperature was one of the main drivers in the model followed by vegetation cover.
Nymphs were restricted to only 17.5% of the modelled area but, respectively, 73.5%, 67.1% and 78.8% of the human populations lived within 5 km of these areas in Denmark, Norway and Sweden. Conclusion: The model suggests that increasing temperatures in the future may expand tick distribution geographically in northern Europe, but this may only affect a small additional proportion of the human population.
Language: | English |
---|---|
Publisher: | European Centre for Disease Prevention and Control (ECDC) |
Year: | 2019 |
Pages: | 35-45 |
ISSN: | 15607917 and 1025496x |
Types: | Journal article |
DOI: | 10.2807/1560-7917.ES.2019.24.9.1800101 |
ORCIDs: | Baum, Andreas |
Animals Climate Denmark Encephalitis, Tick-Borne Environment Environmental Exposure Geography Humans Ixodes Ixodes ricinus Lyme Disease Models, Biological Norway Nymph Phylogeography Population Dynamics Remote Sensing Technology Scandinavian and Nordic Countries Seasons Sweden Tick Infestations boosted regression trees climate environmental satellite data exposure risk human population density northern Europe public health tick-borne disease