, 2012, Eurosurveillance Editorial, 2012 and Reusken et al., 2012). To date, these studies have not found any evidence of human infection. It is clear, however, that the potential role of Culicoides in transmitting arboviruses both to and between humans in Europe has not been considered in detail from an entomological perspective ( Reusken et al., 2012). In order to gain a clearer

understanding of the likelihood of transmission by Culicoides of arboviruses both to and between humans it is therefore Selleckchem Decitabine necessary to consider both the likelihood of future incursions and their potential for wider-scale spread in this context. The routes by which Culicoides-borne arboviruses can be introduced into new ecosystems have been reviewed in detail, particularly with reference to the BTV-8 outbreak in northern Europe

( Carpenter et al., 2009, Mintiens et al., 2008 and Napp et al., 2013). Most commonly, incursions arise from the wind-assisted movement of infectious Culicoides midges ( Burgin et al., 2013, Mellor and Wittmann, 2002 and Sellers, 1992) or imported viraemic livestock ( Sellers and Taylor, PD173074 in vitro 1980) and hence are predictable in a wider sense where monitoring of occurrence is carried out and reported effectively in regions of transmission. The unlicensed use of partially-attenuated BTV vaccine strains is also relatively straightforward to trace using molecular phylogenetics and is known to have resulted in the transient appearance of BTV-6 ( van Rijn et al., 2012) and BTV-11 ( De Clercq et al., 2009) in Europe. While these routes can explain the majority of incursions of Culicoides-borne arboviruses into Europe, the method(s) of movement of BTV-8, BTV-25 and SBV into the region remain unknown ( Carpenter et al., 2009 and Maan et al., 2008). During the initial stages of the BTV-8 outbreak, there was a general assumption that the incursion was precipitated by increases in global shipping of cargo, livestock, wildlife and humans, factors that have been invoked frequently to explain

the emergence of other vector-borne ID-8 diseases (Kilpatrick and Randolph, 2012). Circumstantial evidence that these routes of entry could be involved was initially provided by the identification of BTV-8 index cases in the Maastricht region of the Netherlands, an international transport hub for plants, animals and humans, although later studies appeared to suggest early occurrence of the virus in ruminants on farms close to national parks in Belgium (Saegerman et al., 2010). The epidemiological relevance of this conclusion in mode of introduction has not been investigated in detail. Introduction of arboviruses such as BTV-8 could occur through the movement of infected Culicoides vectors associated with animal or human transport or through inadvertent inclusion with other cargoes, such as cut flowers.