Xenomonitoring of Mosquitoes (Diptera: Culicidae) for the Presence of Filarioid Helminths in Eastern Austria

Abstract

Information on mosquito-borne filarioid helminths in Austria is scarce, but recent discoveries of Dirofilaria repens indicate autochthonous distribution of this parasite in Eastern Austria. In the current xenomonitoring study, more than 48,000 mosquitoes were collected in Eastern Austria between 2013 and 2015, using different sampling techniques and storage conditions, and were analysed in pools with molecular tools for the presence of filarioid helminth DNA. Overall, DNA of D. repens, Setaria tundra, and two unknown filarioid helminths were documented in twenty mosquito pools within the mitochondrial cox1 gene (barcode region). ese results indicate that S. tundra, with roe deer as definite hosts, is common in Eastern Austria, with most occurrences in floodplain mosquitoes (e.g., Aedes vexans). Moreover, DNA of D. repens was found in an Anopheles plumbeus mosquito close to the Slovakian border, indicating that D. repens is endemic in low prevalence in Eastern Austria. is study shows that xenomonitoring is an adequate tool to analyse the presence of filarioid helminths, but results are influenced by mosquito sampling techniques, storage conditions, and molecular protocols.

DNA-aided identification of Culex mosquitoes (Diptera: Culicidae) reveals unexpected diversity in underground cavities in Austria

“…Mosquitoes (Culicidae) include vectors of human and veterinary pathogens such as arboviruses, haemosporidians and filarioid nematodes (Norris 2004 ; Schoener et al 2017 ; Übleis et al 2018 ). Distribution and transmission of these pathogens are regulated through communities of potential vector organisms (Zittra et al 2017a ).…”

Screening of mosquitoes for filarioid helminths in urban areas in south western Poland—common patterns in European Setaria tundra xenomonitoring studies

“…Lack of S. tundra infections in Culex mosquitoes could be explained by their rare feeding on C. capreolus (Börstler et al 2016 ). Therefore, the host preference might be the most likely explanation why S. tundra has not been found in Culex mosquitoes in most European xenomonitoring studies (Czajka et al 2012 ; Kronefeld et al 2014 ; Zittra et al 2015 ) with the exception of the very recent Austrian study (Übleis et al 2018 ). The results of the phenology, feeding patterns, and molecular xenomonitoring studies constitute complementary sources of information on parasite biology, and the results of independent European studies seem to be mutually confirmatory with respect to Ae.…”

The Incidence of Dirofilaria immitis in Shelter Dogs and Mosquitoes in Austria

“…algeriensis and An. maculipennis complex in Austria near the Hungarian border, and no DNA of D. immitis has been found to date [ 11 ]. Still, the noticeable increase in the prevalence of dirofilariosis in imported shelter dogs is a serious risk factor for endemisation, particularly because of the presence of several mosquito species in Austria potentially able to transmit Dirofilaria spp.…”

“…The occurrence of D. repens could be considered a model for the estimated future distribution of D. immitis , as the heartworm seems to be spreading mainly to the areas where D. repens has already established itself [ 4 , 8 ]. The first autochthonous findings of D. repens in mosquitoes in Austria were made in 2012, and seven cases of cutaneous dirofilariosis in dogs were thought to be autochthonous infections until 2014, while the first autochthonous D. repens infection in humans was found even earlier, in 2006 [ 9 , 10 , 11 ]. By 2014, a total of 25 infections with D. immitis had been reported in dogs in Austria.…”