Kohn et al.
Dermacentor reticulatus in Berlin/Brandenburg (Germany): Activity patterns and associated pathogens
Ticks Tick Borne Dis., in press, https://doi.org/10.1016/j.ttbdis.2018.10.003
The tick species Dermacentor reticulatus is emerging in Central Europe and is the second most important tick species in various regions of Europe. Habitats for D. reticulatus are heterogenous. This tick can be found in moist areas, alluvial forests and meadows, but also in parks and fallow land in urban areas. It has been shown that D. reticulatus can harbor various pathogens, among which are Borrelia, Rickettsia, Babesia, Francisella, Theileria, Anaplasma and TBE virus. The authors have studied the seasonal patterns of D. reticulatus throughout the year (from 2010 to 2012) in Berlin and in the federal state of Brandenburg (in the northeast of Germany). Furthermore, PCR analyses were carried out for the detection of various pathogens in more than 9000 adult D. reticulatus ticks (collected by flagging). Except for during summer, a significantly higher number of D. reticulatus was found compared to Ixodes ricinus in autumn and winter (and in spring at one site). Questing ticks showed a bimodal pattern of abundance and were found especially in spring (March until end of May) and autumn (September to end of November). Winter time showed an irregular occurrence of D. reticulatus. The D. reticulatus ticks collected showed an average prevalence of 64% for Rickettsia. In contrast to the high frequency of Rickettsia, no Babesia sp. were found in the analyzed ticks. Analyses of DNA specific for Anaplasma sp., Ehrlichia and Candidatus Neoehrlichia mikurensis revealed an overall prevalence of 0.05%. The detection of A. phagocytophilium was the first detection of this species in questing D. reticulatus in Germany. Borrelia was detected from 0% to 0.47% in questing ticks depending on the sampling sites. B. miyamotoi was detected for the first time in D. reticulatus. People should be aware that the ticks I. ricinus and D. reticulatus are co-endemic in various parts of Germany and together can be active throughout the year and can harbor a variety of medically important pathogens.