BackgroundDespite long-term research on dirofilariosis in Slovakia, little attention has thus far been paid to Dirofilaria vectors. The particular aim of the present study was molecular screening for filarioid parasites in two different habitats of Bratislava, the capital city of Slovakia. In addition, the effect of urbanisation on mosquito species abundance and composition, associated with the risk of mosquito-borne infections, was studied and discussed.MethodsMosquitoes were identified by morphological features, and molecular methods were also used for determination of selected individuals belonging to cryptic species from the Anopheles maculipennis and Culex pipiens complexes. The presence of filarioid DNA (Dirofilaria repens, Dirofilaria immitis and Setaria spp.) was detected using standard PCR approaches and sequencing.ResultsA total of 6957 female mosquitoes were collected for the study. Overall, the most abundant mosquito species was Aedes vexans, closely followed by unidentified members of the Cx. pipiens complex and the less numerous but still plentiful Ochlerotatus sticticus species. Further investigation of mosquito material revealed 4.26% relative prevalence of Dirofilaria spp., whereby both species, D. repens and D. immitis, were identified. The majority of positive mosquito pools had their origin in a floodplain area on the outskirts of the city, with a relative prevalence of 5.32%; only two mosquito pools (1.26%) were shown to be positive in the residential zone of Bratislava. Setaria spp. DNA was not detected in mosquitoes within this study.ConclusionsThe study presented herein represents initial research focused on molecular mosquito screening for filarioid parasites in urban and urban-fringe habitats of Bratislava, Slovakia. Molecular analyses within the Cx. pipiens complex identified two biotypes: Cx. pipiens biotype pipiens and Cx. pipiens biotype molestus. To our knowledge, Dirofilaria spp. were detected for the first time in Slovakia in mosquitoes other than Ae. vexans, i.e. D. repens in Anopheles messeae and unidentified members of An. maculipennis and Cx. pipiens complexes, and D. immitis in Coquillettidia richiardii and Cx. pipiens biotype pipiens. Both dirofilarial species were found in Och. sticticus. The suitable conditions for the vectors’ biology would represent the main risk factor for dirofilariosis transmission.

Until recently Dirofilaria immitis, the causative agent of serious canine heartworm disease, has been detected relatively infrequently in Central Europe in comparison with the predominant D. repens species. In the present study, the elevated number of heartworm cases among dogs from a breeding establishment in south-western Slovakia is described. Out of 25 dogs examined, dirofilariasis was detected by single or several diagnostic approaches in 18 animals, which represents a mean prevalence of 72.0%. D. immitis was confirmed in 16 (64.0%) of the infected dogs and D. repens in 8 dogs (32.0%). All cases of D. immitis infection were detected in areas regarded as D. repens-endemic to date. Following the presented results and discussed circumstances, the question of whether the real prevalence of canine heartworm disease in Slovakia, or even in Central Europe as a whole, has been underestimated, or if D. immitis is currently becoming endemic in this area.

261 SummaryThe aim of our study was to determine the prevalence of toxocariasis in Bratislava and smaller towns in western Slovakia. During 2006 -2011, sand samples collected from 121 sandpits were investigated: 63 sandpits were from Bratislava City and 58 from sandpits in towns outside Bratislava (Malacky, Pezinok Stupava). In Bratislava, 27 % of examined sandpits were contaminated with Toxocara spp. eggs. In smaller towns eggs of Toxocara spp. were found from three sandpits (6.8 %) of Pezinok and Stupava only. In Malacky, no faeces and no eggs were found in any sandpits. Faecal samples of 1436 dogs and 263 cats were investigated. T. canis eggs were found in the faeces of 16.5 % dogs and T. cati in 18.6 % of examined cats. Toxocariasis of dogs was significantly higher in smaller towns such as the city Bratislava (χ2 = 10.88 for P ≤ 0.001). The difference in prevalence of T. cati in cats bred in Bratislava and outside Bratislava was not confirmed (P ≤ 0.05). 382 pregnant women were examined by ELISA. Anti-Toxocara antibodies were detected in 32 women (8.4 %). The difference in seroprevalence of women coming from Bratislava (6.6 %) and smaller towns outside Bratislava (11.0 %) was not statistically significant (χ2 = 1.6; P ≤ 0.05).

Palaeolimnological reconstruction of the aquatic environment in Lake Komořany, based on sedimentology, geochemistry, and diatom and macrofossil analyses in the littoral part of the basin, reflects the mid‐Holocene history of the profile from its origin c. 9100 cal. a BP to its final transformation into an alder carr c. 4100 cal. a BP. The existence of the littoral zone can be best explained by increased precipitation during the studied interval. A stable diatom community, diatom‐inferred total phosphorus (50–80 μg L−1) and pH (~7.6), along with stable concentrations of elements associated with changes in its watershed indicate a long‐lasting, balanced aquatic environment with no major shifts attributable to external factors, including climate change. From c. 4700 cal. BP, there started a transition to terrestrial conditions, caused by either natural infilling processes or decreased precipitation. Alternation of remarkable dry/wet phases was not detected, in contrast to numerous analogous central European and supraregional records. Potential human impact was revealed through increases of Corylus and Populus pollen in the Neolithic. These anthropogenic changes in the lake surroundings had no detectable influence on the lacustrine environment. The gathered data suggest undramatic, balanced mid‐Holocene environmental and climatic settings for this central European locality, in direct contrast to numerous analogous studies from the region emphasizing fluctuations and shifts found in the sediment record.