Browsing by Person "Fachet-Lehmann, Katrin"

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From import to establishment? Experimental evidence for seasonal outdoor survival of two Rhipicephalus species in Germany
(2025) Fachet-Lehmann, Katrin; Lindau, Alexander; Mackenstedt, Ute
The brown dog tick (Rhipicephalus sanguineus s.l.), though not endemic in Germany, is regularly introduced via travelers with dogs and imported rescue dogs. Due to its relevance in veterinary and human medicine, its potential to establish in Germany’s climate is of interest. Although previous studies confirm indoor survival and reproduction of R. sanguineus s.s. in Germany, climate change and milder winters may also allow outdoor survival. This study assessed the survival of R. sanguineus s.s. and R. innaei from February 2023 to May 2024 using laboratory-bred ticks placed at indoor and outdoor sites. Tick survival (adults, nymphs, larvae) was monitored weekly, along with temperature and humidity. Reproductive success was evaluated via oviposition and larval hatching. R. sanguineus s.s. adults survived up to 44 weeks, nymphs up to 20 weeks, and larvae up to 5 weeks. R. innaei showed shorter survival (37, 10, and 4 weeks, respectively). Successful oviposition and larval hatching occurred outdoors between May´23 and September´23 for both species. However, winter survival was not observed; all ticks died following sub-zero temperatures in December´23. Despite the inability to overwinter outdoors, both species can survive for extended periods in spring and summer and may enter homes via dogs, where conditions favor year-round survival. Their ability to transition indoors via dogs, where conditions favor year-round survival, suggests a potential for establishment in Germany through combined indoor and seasonal outdoor persistence.
Tick hazard in a Central European country: Mapping Europe’s principal tick-borne disease vector across Germany
(2025) Springer, Andrea; Lindau, Alexander; Fachet-Lehmann, Katrin; Kämmer, Daniel; Bulling, Ingrid; Knoll, Steffen; Król, Nina; Fischer, Dominik; Fischer, Luisa; Drehmann, Marco; Chitimia-Dobler, Lidia; Noll, Madeleine; Vineer, Hannah Rose; Kahl, Olaf; Pfeffer, Martin; Strube, Christina; Mackenstedt, Ute
The most common European tick species, Ixodes ricinus, is the principal vector of Borrelia and tick-borne encephalitis virus and several other pathogens of public health relevance in Europe. Comprehensive data on tick abundance and the underlying ecological drivers are crucial for developing awareness and control strategies and to assess future changes in tick-borne disease risk. We aimed to provide a Germany-wide map of I. ricinus abundance to aid in disease transmission risk assessment. During 2018−2020, questing tick density was assessed at 83 sites across the whole country by drag flagging, whereby 49,344 I. ricinus nymphs and adults were collected. Relationships between climate, land cover, and monthly questing I. ricinus nymph density were explored and used to draw an abundance map. Highest tick hazard was observed in areas near the coast with mild winters and moist springs, and in mid-elevation mountain ranges, which represent popular tourist destinations. The ticks’ seasonal activity pattern was predominantly unimodal. The fact that the observed regional differences are contradictory to a previous estimation based on a combination of regional studies illustrates the need for an extensive and coordinated sampling effort to reliably estimate tick abundance at larger spatial scales. Combined with data on tick-borne pathogens, our study enables estimating the density of infected ticks and consequently the risk of acquiring an infectious tick bite. Moreover, the observed relationships with climate and land cover can help to predict future developments of tick hazard under different climate scenarios in Central Europe.
Unwanted souvenirs - import routes and pathogen detection of the non-endemic tick Rhipicephalus sanguineus s.l. in Germany
(2025) Fachet-Lehmann, Katrin; Lindau, Alexander; Mackenstedt, Ute
Ticks of the Genus Rhipicephalus occur worldwide. Especially members of Rh. sanguineus s.l. are primarily associated with dogs. As unwanted souvenirs, they are introduced by dogs into non-endemic areas such as Germany, where they can establish and reproduce indoors . A citizen-science study was conducted between 2019 and 2024, asking interested citizens to report tick infestations and send in travel related tick findings which were associated with dogs and were focused on Rhipicephalus species. Tick species were identified using the 16S rRNA gene and tested for pathogens associated with the genus Rhipicephalus . In addition, each tick introduction was considered as a case and categorized and analyzed individually. During the study period, 44 cases were reported. In 17 cases tick specimens were identified as Rh. sanguineus s.s., Rh. rutilus , Rh. linnaei, Rh. turanicus , and Rh. haemaphysaloides which were imported from other European countries and Sri Lanka. Neither Hepatozoon canis , Ehrlichia canis nor Babesia vogeli were detected in any of the 780 received specimens. In contrast, Rickettsia spp. was detected in 50 specimens from six independent cases, with Rickettsia massiliae being identified in 44 specimens. The import of dogs from abroad as well as travel with dogs lacking appropriate tick prophylaxis are responsible for more than 80% of cases. This Project highlights the risk of introductions of non-endemic tick species. Also, professionals such as veterinarians, animal welfare organizations and pest controllers need to be made aware of the possible introduction of Rhipicephalus spp. to ensure early recognition and rapid elimination of the ticks.