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Research article - Peer-reviewed, 2020

Spatial patterns of pathogen prevalence in questing Ixodes ricinus nymphs in southern Scandinavia, 2016

Kjaer, Lene Jung; Klitgaard, Kirstine; Soleng, Arnulf; Edgar, Kristin Skarsfjord; Lindstedt, Heidi Elisabeth H.; Paulsen, Katrine M.; Andreassen, Ashild Kristine; Korslund, Lars; Kjelland, Vivian; Slettan, Audun; Stuen, Snorre; Kjellander, Petter; Christensson, Madeleine; Teravainen, Malin; Baum, Andreas; Jensen, Laura Mark; Bodker, Rene

Abstract

Tick-borne pathogens cause diseases in animals and humans, and tick-borne disease incidence is increasing in many parts of the world. There is a need to assess the distribution of tick-borne pathogens and identify potential risk areas. We collected 29,440 tick nymphs from 50 sites in Scandinavia from August to September, 2016. We tested ticks in a real-time PCR chip, screening for 19 vector-associated pathogens. We analysed spatial patterns, mapped the prevalence of each pathogen and used machine learning algorithms and environmental variables to develop predictive prevalence models. All 50 sites had a pool prevalence of at least 33% for one or more pathogens, the most prevalent being Borrelia afzelii, B. garinii, Rickettsia helvetica, Anaplasma phagocytophilum, and Neoehrlichia mikurensis. There were large differences in pathogen prevalence between sites, but we identified only limited geographical clustering. The prevalence models performed poorly, with only models for R. helvetica and N. mikurensis having moderate predictive power (normalized RMSE from 0.74-0.75, R-2 from 0.43-0.48). The poor performance of the majority of our prevalence models suggest that the used environmental and climatic variables alone do not explain pathogen prevalence patterns in Scandinavia, although previously the same variables successfully predicted spatial patterns of ticks in the same area.

Published in

Scientific Reports
2020, volume: 10, number: 1, article number: 19376
Publisher: NATURE RESEARCH

Authors' information

Kjaer, Lene Jung
University of Copenhagen
Klitgaard, Kirstine
Technical University of Denmark
Soleng, Arnulf
Norwegian Institute of Public Health (NIPH)
Edgar, Kristin Skarsfjord
Norwegian Institute of Public Health (NIPH)
Lindstedt, Heidi Elisabeth H.
Norwegian Institute of Public Health (NIPH)
Paulsen, Katrine M.
Norwegian Institute of Public Health (NIPH)
Andreassen, Ashild Kristine
Norwegian Institute of Public Health (NIPH)
Korslund, Lars
University of Agder
Kjelland, Vivian
University of Agder
Slettan, Audun
University of Agder
Stuen, Snorre
Norwegian University of Life Sciences
Swedish University of Agricultural Sciences, Department of Ecology
Swedish University of Agricultural Sciences, Department of Ecology
Swedish University of Agricultural Sciences, Department of Ecology
Baum, Andreas
Technical University of Denmark
Jensen, Laura Mark
University of Copenhagen
Bodker, Rene
University of Copenhagen

UKÄ Subject classification

Ecology

Publication Identifiers

DOI: https://doi.org/10.1038/s41598-020-76334-5

URI (permanent link to this page)

https://res.slu.se/id/publ/109987