title: Climate change and the spread of vector-borne diseases: using approximate Bayesian computation to compare invasion scenarios for the bluetongue virus vector Culicoides imicola in Italy.
abstract: Bluetongue (BT) is a commonly cited example of a disease with a distribution believed to have recently expanded in response to global warming. The BT virus is transmitted to ruminants by biting midges of the genus Culicoides, and it has been hypothesized that the emergence of BT in Mediterranean Europe during the last two decades is a consequence of the recent colonization of the region by Culicoides imicola and linked to climate change. To better understand the mechanism responsible for the northward spread of BT, we tested the hypothesis of a recent colonization of Italy by C. imicola, by obtaining samples from more than 60 localities across Italy, Corsica, Southern France, and Northern Africa (the hypothesized source point for the recent invasion of C. imicola), and by genotyping them with 10 newly identified microsatellite loci. The patterns of genetic variation within and among the sampled populations were characterized and used in a rigorous approximate Bayesian computation framework to compare three competing historical hypotheses related to the arrival and establishment of C. imicola in Italy. The hypothesis of an ancient presence of the insect vector was strongly favoured by this analysis, with an associated P ≥ 99%, suggesting that causes other than the northward range expansion of C. imicola may have supported the emergence of BT in southern Europe. Overall, this study illustrates the potential of molecular genetic markers for exploring the assumed link between climate change and the spread of diseases.
authors.affiliation: Evolutionary Biology and Ecology, Université Libre de Bruxelles, Brussels, Belgium. pmarduly@ulb.ac.be
authors.forename: Patrick
authors.initials: P
authors.lastname: Mardulyn
authors.forename: Maria
authors.initials: M
authors.lastname: Goffredo
authors.forename: Annamaria
authors.initials: A
authors.lastname: Conte
authors.forename: Guy
authors.initials: G
authors.lastname: Hendrickx
authors.forename: Rudolf
authors.initials: R
authors.lastname: Meiswinkel
authors.forename: Thomas
authors.initials: T
authors.lastname: Balenghien
authors.forename: Soufien
authors.initials: S
authors.lastname: Sghaier
authors.forename: Youssef
authors.initials: Y
authors.lastname: Lohr
authors.forename: Marius
authors.initials: M
authors.lastname: Gilbert
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D001820:Bluetongue virus; D002519:Ceratopogonidae / Q000235:genetics* / Q000821:virology; D057231:Climate Change; D019295:Computational Biology; D005602:France / Q000453:epidemiology; D056426:Genetic Loci; D005819:Genetic Markers; D014644:Genetic Variation; D005838:Genotype; D007303:Insect Vectors / Q000235:genetics* / Q000821:virology; D007558:Italy / Q000453:epidemiology; D018895:Microsatellite Repeats; D012756:Sheep
chemical_list: D005819:Genetic Markers