title: Development of Dirofilaria immitis within the mosquito Aedes (Finlaya) koreicus, a new invasive species for Europe.
abstract: BACKGROUND
  Over the recent decades, container-breeding mosquito species belonging to the genus Aedes have frequently been recorded far from their place of origin. Aedes koreicus was first reported in north-eastern Italy in 2011, in a region endemic for Dirofilaria immitis, the agent of canine heartworm disease. The vector competence of Ae. koreicus for D. immitis was here tested under laboratory conditions, by infecting mosquitoes with a local strain of D. immitis.
  
  
  METHODS
  Blood containing 3000 microfilariae/ml was offered to 54 mosquitoes (T group) while 29 were left as a control (C group). Mosquitoes killed at scheduled days post infection (dpi) and naturally dead were divided in head, thorax and abdomen and examined for D. immitis larval stages by dissection under a microscope and molecularly.
  
  
  RESULTS
  Of the 45 engorged mosquitoes in T, 32 (71.1%) scored positive for D. immitis larval stages. L3 were found as early as 8 dpi in the Malpighian tubules and then in the thorax, salivary glands, palp and proboscis. At the end of the study a total of 18 mosquitoes developed L3 giving an estimated infection rate at 12 dpi of 68.2% and a vector efficiency index of 25.2%. The rate of mortality in T group within the first 9 days post infection was significantly higher in T group (47.6%) than in C group (8.3%) (p < 0.01). The concordance between microscopy and PCR was high (0.8-0.9), however, a positivity for D. immitis in the head was found molecularly at 13 dpi, three days before microscopy.
  
  
  CONCLUSIONS
  Aedes koreicus, a new invasive species for Europe, is most likely a competent vector of D. immitis being of potential relevance in the natural cycle of the parasite. This poses a new threat for animal and human health in endemic areas for dirofilariosis and enhances the risk of spreading the infection in previously non-endemic areas. These results stress the importance of active surveillance and control strategies to minimize the risk of introduction of invasive alien species.
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10; 35020 Legnaro, Padua, Italy. fmontarsi@izsvenezie.it.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Montarsi
authors.affiliation: Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia. silvia.ciocchetta@qimrberghofer.edu.au.|Queensland University of Technology, Brisbane, Queensland, Australia. silvia.ciocchetta@qimrberghofer.edu.au.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ciocchetta
authors.affiliation: Mosquito Control Laboratory, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia. Greg.Devine@qimrberghofer.edu.au.
authors.forename: Gregor
authors.initials: G
authors.lastname: Devine
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10; 35020 Legnaro, Padua, Italy. sravagnan@izsvenezie.it.
authors.forename: Silvia
authors.initials: S
authors.lastname: Ravagnan
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10; 35020 Legnaro, Padua, Italy. fmutinelli@izsvenezie.it.
authors.forename: Franco
authors.initials: F
authors.lastname: Mutinelli
authors.affiliation: Dipartimento di Medicina Animale, Produzioni e Salute, Università degli Studi di Padova, Viale dell'Università, 16; 35020 Legnaro, Padua, Italy. antonio.frangipane@unipd.it.
authors.forename: Antonio
authors.initials: A
authors.lastname: Frangipane di Regalbono
authors.affiliation: Dipartimento di Medicina Veterinaria, Università degli Studi di Bari, Valenzano, 70010, Bari, Italy. domenico.otranto@uniba.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: Otranto
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università, 10; 35020 Legnaro, Padua, Italy. gcapelli@izsvenezie.it.
authors.forename: Gioia
authors.initials: G
authors.lastname: Capelli
mesh_terms: D000330:Aedes / Q000469:parasitology*; D000818:Animals; D004183:Dirofilaria immitis / Q000235:genetics / Q000302:isolation & purification*; D004184:Dirofilariasis / Q000453:epidemiology* / Q000469:parasitology; D004283:Dog Diseases / Q000453:epidemiology* / Q000469:parasitology; D004285:Dogs; D005060:Europe / Q000453:epidemiology; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology*; D058865:Introduced Species; D007558:Italy / Q000453:epidemiology; D007814:Larva