The few available direct surveys of biting rates inflicted by livestock-associated species on human populations have indicated either low or intermittent attack rates ( Dzhafarov, 1964, Overgaard Nielsen, 1964 and Szadziewski and Kubica, 1988). These rates can occasionally be increased by the removal of alternative hosts or transient increases in suitable larval habitat, particularly in species that can develop in organically enriched environments e.g. C. nubeculosus ( Szarbό, 1966). In contrast to species inflicting biting nuisance on humans, all the primary Culicoides vectors of livestock arboviruses worldwide

are currently believed to require a blood meal before egg production (anautogeny), including AZD2281 research buy C. brevitarsis in Australasia Metformin purchase ( Kettle and Campbell, 1983); C. sonorensis in the Nearctic ( Linley and Braverman, 1986) and C. imicola in the Afrotropic region

( Braverman and Mumcuoglu, 2009). In 2011 a novel pathogen, provisionally named Schmallenberg virus (SBV), was discovered in Germany in adult cattle presenting clinical signs including reduced milk yield and diarrhoea (Hoffmann et al., 2012 and Garigliany et al., 2012). Subsequently, SBV was demonstrated to cause congenital deformities in calves and lambs when dams were infected in the first trimester following insemination and this has since been identified as SBV’s primary impact on ruminant production (Davies et al., 2012 and Elbers et al.,

2012). Following detection, a range of Culicoides species were rapidly implicated in the transmission of SBV through a series of studies in the Netherlands ( Elbers et al., 2013) and Belgium ( De Regge et al., 2012). Species thought to be involved included many of those previously implicated in transmission of bluetongue virus (BTV) during unprecedented incursions into both northern and southern Europe ( Carpenter et al., 2009 and Purse et al., 2005). Before these excursions into northern Europe, the risk of BTV infection causing clinical disease in humans was known to be negligible, and it subsequently was rapidly dismissed in discussions in the public domain. In contrast, the novel nature NADPH-cytochrome-c2 reductase of SBV led to difficulties in immediately assessing the probability and consequences of human exposure ( Ducomble et al., 2012). From phylogenetic characterization, it was inferred that SBV shares a close relationship with other arboviruses that were not known to cause appreciable clinical disease in humans, including Shamonda, Aino and Akabane viruses (Doceul et al., 2013 and Reusken et al., 2012). While this information was useful in informing risk assessments, it was clear that policy makers were unsure about the degree of confidence that could be assigned to a low risk of pathogenicity inferred on this basis (Ducomble et al., 2012, Eurosurveillance Editorial, 2012 and Reusken et al., 2012).