title: Understanding West Nile virus ecology in Europe: Culex pipiens host feeding preference in a hotspot of virus emergence.
abstract: BACKGROUND
  Understanding wildlife disease ecology is becoming an urgent need due to the continuous emergence and spread of several wildlife zoonotic diseases. West Nile Virus (WNV) is the most widespread arthropod-borne virus in the world, and in recent decades there has been an increase both in geographic range, and in the frequency of symptomatic infections in humans and wildlife. The principal vector for WNV in Europe is the common house Culex pipiens mosquito, which feeds on a wide variety of vertebrate host species. Variation in mosquito feeding preference has been described as one of the most influential parameters driving intensity and timing of WNV infection in the United States, but feeding preferences for this species have been little studied in Europe.
  
  
  METHODS
  Here, we estimated feeding preference for wild Cx. pipiens in northern Italy, using molecular analysis to identify the origin of blood meals, and avian census to control host abundance variations. Additionally, we used host bird odour extracts to test experimentally mosquito preferences in the absence of environmental variations.
  
  
  RESULTS
  For the first time, we demonstrate a clear feeding preference for the common blackbird (Turdus merula), both for wild collected specimens and in the lab, suggesting a potential important role for this species in the WNV epidemiology in Europe. A seasonal decrease in abundance of blackbirds is associated with increased feeding on Eurasian magpies (Pica pica), and this may be linked to seasonal emergence of WNV in humans. Feeding preferences on blackbirds are more marked in rural areas, while preference for magpies is higher in peridomestic areas. Other species, such as the house sparrow (Passer domesticus) appear to be selected by mosquitoes opportunistically in relation to its abundance.
  
  
  CONCLUSIONS
  Our findings provide new insights into the ecology of Cx. pipiens in Europe and may give useful indications in terms of implementing targeted WNV surveillance plans. However, a clearer understanding of spatio-temporal variations of Cx. pipiens feeding preferences, and targeted studies on reservoir competence for WNV for these species are therefore now urgently needed as this is essential to describe disease dynamics and quantify virus transmission risk.
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach. 1, 38010 San Michele all'Adige, Trento, Italy. annapaola.rizzoli@fmach.it.
authors.forename: Annapaola
authors.initials: A
authors.lastname: Rizzoli
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach. 1, 38010 San Michele all'Adige, Trento, Italy. luca.bolzoni@izsler.it.|Direzione Sanitaria - Servizio di Analisi del Rischio, Istituto Zooprofilattico Sperimentale della Lombardia e dell'Emilia Romagna, Via dei Mercati 13, 43100, Parma, Italy. luca.bolzoni@izsler.it.
authors.forename: Luca
authors.initials: L
authors.lastname: Bolzoni
authors.affiliation: Cardiff University, School of Biosciences, Biomedical Science Building, Museum Avenue, Cardiff, CF10 3AX, United Kingdom. chadwickea@cardiff.ac.uk.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Chadwick
authors.affiliation: Laboratory of Parasitology - Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020, Legnaro (Padova), Italy. gcapelli@izsvenezie.it.
authors.forename: Gioia
authors.initials: G
authors.lastname: Capelli
authors.affiliation: Laboratory of Parasitology - Istituto Zooprofilattico Sperimentale delle Venezie, Viale dell'Università 10, 35020, Legnaro (Padova), Italy. fmontarsi@izsvenezie.it.
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Montarsi
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach. 1, 38010 San Michele all'Adige, Trento, Italy. michela.grisenti@fmach.it.|Department of Veterinary Sciences, University of Torino, Largo Paolo Braccini 2, 10095, Grugliasco, Torino, Italy. michela.grisenti@fmach.it.
authors.forename: Michela
authors.initials: M
authors.lastname: Grisenti
authors.affiliation: Department of Wetland Ecology Estación Biológica Doñana, Consejo Superior de Investigaciones Cientificas, Avda. Americo Vespucio s/n, 41092, Sevilla, Spain. jmp@ebd.csic.es.
authors.forename: Josue Martínez
authors.initials: JM
authors.lastname: de la Puente
authors.affiliation: Department of Wetland Ecology Estación Biológica Doñana, Consejo Superior de Investigaciones Cientificas, Avda. Americo Vespucio s/n, 41092, Sevilla, Spain. quini@ebd.csic.es.
authors.forename: Joaquin
authors.initials: J
authors.lastname: Muñoz
authors.affiliation: Department of Wetland Ecology Estación Biológica Doñana, Consejo Superior de Investigaciones Cientificas, Avda. Americo Vespucio s/n, 41092, Sevilla, Spain. jordi@ebd.csic.es.
authors.forename: Jordi
authors.initials: J
authors.lastname: Figuerola
authors.affiliation: Department of Wetland Ecology Estación Biológica Doñana, Consejo Superior de Investigaciones Cientificas, Avda. Americo Vespucio s/n, 41092, Sevilla, Spain. soriguer@ebd.csic.es.
authors.forename: Ramon
authors.initials: R
authors.lastname: Soriguer
authors.affiliation: Department of Sustainable Ecosystems and Bioresources, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach. 1, 38010 San Michele all'Adige, Trento, Italy. gianfranco.anfora@fmach.it.
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Anfora
authors.affiliation: Department of Infectious, Parasitic and Immune-Mediated Diseases, Istituto Superiore di Sanità, Viale Regina Elena, 299, 00161, Rome, Italy. marco.diluca@iss.it.
authors.forename: Marco
authors.initials: M
authors.lastname: Di Luca
authors.affiliation: Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, Via E. Mach. 1, 38010 San Michele all'Adige, Trento, Italy. roberto.rosa@fmach.it.
authors.forename: Roberto
authors.initials: R
authors.lastname: Rosà
mesh_terms: D000818:Animals; D001717:Birds / Q000097:blood / Q000235:genetics; D003465:Culex / Q000502:physiology* / Q000821:virology; D004247:DNA / Q000235:genetics; D004197:Disease Reservoirs; D005247:Feeding Behavior / Q000502:physiology*; D009812:Odorants; D013045:Species Specificity; D014901:West Nile Fever / Q000453:epidemiology* / Q000821:virology; D014902:West Nile virus / Q000302:isolation & purification*
chemical_list: D004247:DNA