Ličková et al.
Dermacentor reticulatus is a vector of tick-borne encephalitis virus
Ticks Tick Borne Dis. 2020, in press, doi.org/10.1016/j.ttdis.2020.101414
The principal vector for TBE virus are Ixodes ricinus (associated with the European subtype) and I. persulcatus (associated with the Siberian and Far Eastern subtypes). Reports are accumulating on the detection of TBE virus in the tick Dermacentor reticulatus. However, in these studies the detection of TBE virus specific genome is reported, and it cannot directly be concluded that this tick species contributes to the TBE virus transmission cycle. Therefore, the vector competence of D. reticulatus was evaluated through experimental tick infection and in vivo transmission studies.
Adult female D. reticulatus ticks were infected by transcoxal inoculation of 500 PFU of TBE virus. Virus load reached 2.5 x105 gene copies per tick and 6.4×104 PFU per tick after 21 days. Similar results could also be detected after the infection of nymphs. When infected females D. reticulatus ticks were put together with Haemaphysalis inermis nymphs on mice for 1 to 8 days for feeding, virus was detectable in various organs of the mice and also in the nymphs showing that female D. reticulatus can transmit the virus to mice and co-feeding uninfected H. inermis nymphs. Overall, the virus transmission was similar to comparative studies when I. ricinus was used instead of D. reticulatus. The authors concluded that D. reticulatus may play an important role in TBE virus circulation like other proven vector tick species.