Barbara Eigner

Autochthonous Dirofilaria repens in Austria

BackgroundIn Europe animal and human infections due to Dirofilaria repens are increasing.FindingsIn a nationwide screening for filarioid parasites in Austria, 7,632 mosquitoes were collected from June till October 2012 and divided into 437 pools according to same trapping date and sight and mosquito species. For the molecular detection, a real-time PCR approach was followed by conventional PCR. D. repens was detected in the villages Moerbisch and Rust, Burgenland in one Anopheles maculipennis group and one Anopheles algeriensis species pool, respectively.ConclusionsThe geographical distribution of the two positive pools points to the invasion of D. repens from Eastern neighboring countries. The finding of D. repens in mosquito vectors suggests the occurrence of the causative agent for cutaneous dirofilariosis in Austria.

Screening blood-fed mosquitoes for the diagnosis of filarioid helminths and avian malaria.

BackgroundBoth Dirofilaria repens and recently D. immitis are known to be endemic in Hungary. As one of several recent cases, the fatal case of a dog infested with D. immitis in Szeged, Southern Hungary, received attention from the media. Hence it was decided to catch mosquitoes in the garden where the dog lived to screen for filarioid helminths and Plasmodium spp. using molecular tools.MethodsMosquitoes were caught in Szeged, in the garden where the infected dog was kept, in July 2013 with M-360 electric mosquito traps and were stored in ethanol until further procedure. Female mosquitoes were classified to genus level by morphology. Each mosquito was homogenized and analyzed for filarioid helminths and avian malaria using standardized PCR techniques. Positive mosquito samples were further identified to species level by comparing a section of the mitochondrial COI gene to GenBank® entries.ResultsIn this study, 267 blood-fed mosquitoes were caught in July 2013 in Szeged. Subsequent molecular screening revealed that not only D. immitis was present in the analyzed specimens but also DNA of D. repens, Setaria tundra and Plasmodium spp. was confirmed.ConclusionsThe analysis of blood-fed mosquitoes for the diagnosis of Dirofilaria spp. and other mosquito-borne pathogens seems to be an adequate technique to evaluate if filarioid helminths are present in a certain area. Usually only unfed female mosquitoes are analyzed for epidemiological studies. However, blood-fed mosquitoes can only be used for screening if a pathogen is present because the role of the mosquito as vector cannot be classified (blood of bitten host). Furthermore, Setaria tundra was confirmed for the first time in Hungary.

Landscape structure affects distribution of potential disease vectors (Diptera: Culicidae)

BackgroundVector-pathogen dynamics are controlled by fluctuations of potential vector communities, such as the Culicidae. Assessment of mosquito community diversity and, in particular, identification of environmental parameters shaping these communities is therefore of key importance for the design of adequate surveillance approaches. In this study, we assess effects of climatic parameters and habitat structure on mosquito communities in eastern Austria to deliver these highly relevant baseline data.MethodsFemale mosquitoes were sampled twice a month from April to October 2014 and 2015 at 35 permanent and 23 non-permanent trapping sites using carbon dioxide-baited traps. Differences in spatial and seasonal abundance patterns of Culicidae taxa were identified using likelihood ratio tests; possible effects of environmental parameters on seasonal and spatial mosquito distribution were analysed using multivariate statistical methods. We assessed community responses to environmental parameters based on 14-day-average values that affect ontogenesis.ResultsAltogether 29,734 female mosquitoes were collected, and 21 of 42 native as well as two of four non-native mosquito species were reconfirmed in eastern Austria. Statistical analyses revealed significant differences in mosquito abundance between sampling years and provinces. Incidence and abundance patterns were found to be linked to 14-day mean sunshine duration, humidity, water–level maxima and the amount of precipitation. However, land cover classes were found to be the most important factor, effectively assigning both indigenous and non-native mosquito species to various communities, which responded differentially to environmental variables.ConclusionsThese findings thus underline the significance of non-climatic variables for future mosquito prediction models and the necessity to consider these in mosquito surveillance programmes.

Molecular analysis of Anaplasma phagocytophilum and Babesia divergens in red deer (Cervus elaphus) in Western Austria.

Wild ungulates may act as reservoirs of various vector borne pathogens that can infect humans and domestic animals. In the present study, blood samples from 196 red deer (Cervus elaphus) from Western Austria (Vorarlberg, Tyrol and Salzburg) were collected on filter paper and tested for Anaplasmataceae, Piroplasmida, Rickettsia and filarioid helminths using molecular tools. Babesia divergens was detected in ten (5.1%) and Anaplasma phagocytophilum in three (1.5%) of the 196 samples. Filarioid helminths, Rickettsia spp. and Theileria spp. were not detected. These findings indicate that red deer may serve as reservoirs of Babesia divergens and Anaplasma phagocytophilum in Western Austria. Further investigations are needed to assess the presence of these pathogens in ticks in this geographical region, and the significance of these pathogens in both animals and humans.

First record of Orthopodomyia pulcripalpis (Rondani, 1872) (Diptera: Culicidae) in Austria

During a three-year mosquito monitoring from 2014 to 2016, the strictly ornithophilic, originally Mediterranean species Orthopodomyia pulcripalpis (Rondani, 1872) was collected as single specimen for the first time in Austria in the district of Penzing in Vienna. Morphological species determination was confirmed by analysis of the mitochondrial cytochrome c oxidase subunit I gene. We thus not only confirm the existence of another mosquito species in Austria, but also add a new genus to the Austrian Culicidae taxa list.

Morphological and molecular genetic analysis of Synhimantus (Synhimantus) laticeps (Rudolphi, 1819) (Nematoda, Acuariidae) from the barn owl (Tyto alba) and the common kestrel (Falco tinnunculus) in Austria

Summary In the framework of the biodiversity initiative and barcoding project “Austrian Barcode of Life” (ABOL) post mortem examinations of the gastro-intestinal tracts of different species of wild birds were carried out and several adult helminths were retrieved. In the gizzard of two barn owls (Tyto alba) and one common kestrel (Falco tinnuculus) acuariid nematodes belonging to the species Synhimantus (Synhimantus) laticeps (Rudolphi, 1819) were discovered. This report illustrates the identification of this parasitic nematode by morphometric comparison and scanning electron microscopic photographs. Furthermore, genetic identification of individual parasites based on a fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene and the nuclear 18S ribosomal RNA gene was carried out. This report constitutes the first COI-based DNA barcoding of S. (S.) laticeps and its first record in the barn owl (Tyto alba) in Austria.