No abstract

West Nile virus (WNV) is a mosquito-borne flavivirus (the genus Flavivirus, the family Flaviviridae). It belongs

The present study reports on serosurvey on the tick-borne encephalitis virus European subtype (TBEV; genus Flavivirus), and the tick-borne Kemerovo (KEMV) and Tribeč (TRBV) orbivirus (genus Orbivirus) infections in tick-infested and non-infested birds. No virus RNA was detected in the blood clots. Birds were infested mostly by Ixodes ricinus, but Haemaphysalis concinna and I. frontalis were observed too. TBEV, KEMV and TRBV neutralising antibodies (NAb) were detected in the screening microtitration neutralisation test (μVNT). Seropositive samples were further examined in simultaneous μVNT to distinguish TBEV infection from WNV and USUV. KEMV and TRBV infections were also further examined by μVNT against each other. The demonstrated results point to increased TBEV and TRBV seroprevalence in birds over the past several years. This is the first study on KEMV infection in the Slovak bird population, and seropositive juvenile birds suggest its occurrence in a new geographic area. The results indicate the significance of tick infestation rates, seropositivity and specific NAb titre. The reservoir role of birds for TBEV, KEMV and TRBV remains unclear. However, targeted monitoring of birds and vectors is an effective measure of surveillance of arbovirus introduction into new geographic areas.

Considering that tick-borne diseases are on the rise, a full understanding of how pathogen–tick–host interactions can lead to vector behavioral modifications is of high value. Successful transmission of pathogens to their hosts depends on vector mobility and their ability to quest for prey and attack hosts. In our research, the behavior of Dermacentor reticulatus ticks (n = 88) that were positive or negative for Rickettsia spp. (prevalence—36.36%) were analyzed using novel behavioral apparatuses. Tick locomotion and their preference for light or darkness were studied utilizing a multirod arena (MA) and a light/dark test (LDT) optimized for ticks. Behavioral tasks were evaluated using a Smart video-tracking system (Panlab, Spain). The majority of ticks (p < 0.0001) explored in the center of MA during the first 15 minutes. Despite that, most of them (p < 0.01) chose the periphery for questing or resting postures. They also preferred the elevated parts of the rods (p < 0.001) for this behavior. Ticks significantly (p < 0.0001) preferred the light part of the LDT. Rickettsia-infected ticks had higher locomotor activity, manifesting as longer trajectories (p = 0.0221). Our results revealed the possible impact of pathogens on some behavioral patterns of ticks as their vectors, which may significantly increase the probability of pathogen transmission.