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.

This study reports on a fatal case of a captive great grey owl infected with the West Nile virus (WNV) in the zoological garden Košice, eastern Slovakia (Central Europe). The tissue samples of the dead owl were used for virus isolation and genetic characterization. The novel isolate is genetically closer to Hungarian, Greek, and Bulgarian strains from the central/southern European clade of lineage 2 than to the strains previously isolated in Slovakia. Interestingly, it carries NS3-249P, a molecular virulence determinant associated with higher neurovirulence, which has not previously been observed in Slovakia. Subsequent serological investigation of the captive owls revealed additional seropositive animals, indicating local WNV transmission. Although no WNV-positive mosquitoes were found, the presence of the WNV principal vector Culex pipiens complex together with the described fatal case and further serological findings indicate an endemic focus of bird-neurovirulent WNV variant in the area.

The invasive mosquito Aedes ( Hulecoeteomyia ) koreicus (Edwards, 1917), originally native to East Asia, has recently established populations across several European countries. This study provides the first molecular confirmation of Ae. koreicus in Slovakia. Adult females were collected during nationwide mosquito surveillance conducted between June and October 2024. Morphological identification was confirmed by sequencing a fragment of the mitochondrial cytochrome oxidase I (COI) gene. Phylogenetic analysis revealed that Slovak Ae. koreicus sequences clustered with reference sequences from Italy, Hungary, Belgium, and Germany. BLAST analysis showed 98.4–100% nucleotide identity with European Ae. koreicus isolates. Two principal genetic clusters were detected—one related to Hungarian isolates and another to Italian isolates, suggesting multiple introduction pathways or regional spread from established populations in Central Europe. These findings confirm the ongoing expansion of Ae. koreicus in Central Europe.

In this paper the results of a Phoridae collection from Košice Zoo in eastern Slovakia are reported. An unusual trap method was employed – BG-Sentinel 2 mosquito traps combined with CO₂ as an attractant. Between July and October 2023, 73 species of the Phoridae family were recorded, 24 of which are new to the Slovak fauna (1 species from the genus Woodiphora and 23 species from the genus Megaselia). As a result, the total number of Phoridae species documented in Slovakia has increased to 254.

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 min. 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.