Imported Hyalomma ticks in the Netherlands 2018–2020

Abstract Background Ticks of the genus Hyalomma , which are vectors for several tick-borne diseases, occasionally found in areas outside their endemic range including northern parts Europe. The objective this study was to analyse adult ticks that were recently Netherlands. Methods morphologically identified. Cluster analysis, based upon sequence data ( cox1 barcoding) molecular identification, and pathogen detection performed. Additionally, a cross-sectional survey horses conducted actively search summer 2019. Analysis temperature done assess possibility (i) introduced engorged nymphs moulting adults (ii) establishment populations Results Seventeen (one 2018, eleven 2019, five 2020) by citizens reported. Fifteen detected on two humans. Twelve identified as H. marginatum one rufipes four, only photographic images available, sp. No Crimean-Congo haemorrhagic fever virus or Babesia / Theileria parasites detected. One tick tested positive Rickettsia aeschlimannii . In horse survey, no found. temperatures showed arriving migratory birds spring able moult 2019 2020, cumulative daily Netherlands lower than with established populations. Conclusions Our results show regularly nymphs. Under Dutch weather conditions, these develop stage, can be sighted vigilant citizens. Only human pathogen, ticks. risk introduction diseases via is considered low. Establishment permanent unlikely under current climatic conditions. Graphical