Bluetongue, a devastating disease of ruminants, has historically made only brief, sporadic incursions into the fringes of Europe. However, since 1998, six strains of bluetongue virus have spread across 12 countries and 800 km further north in Europe than has previously been reported. We suggest that this spread has been driven by recent changes in European climate that have allowed increased virus persistence during winter, the northward expansion of Culicoides imicola, the main bluetongue virus vector, and, beyond this vector's range, transmission by indigenous European Culicoides species - thereby expanding the risk of transmission over larger geographical regions. Understanding this sequence of events may help us predict the emergence of other vector-borne pathogens.
Throughout its establishment and development sociology has been concerned almost exclusively with problems of life, rather than with the subject of death. However, if we take seriously Peter Berger's (1967) point that death is an essential feature of the human condition that requires people to develop means of coping with it, then to neglect death is to ignore one of the few universal parameters in which social and individual life are constructed. In this paper we examine the relationship between self-identity, the sequestration of death, and the period Anthony Giddens terms `late' or `high modernity', and argue that the organisation and experience of death have become increasingly privatised. This has acquired particular significance as a result of three central characteristics of high modernity: the growing role played by the reflexive re-ordering of biographical narratives in the construction of self-identity (Giddens 1991); the increased identification of the self with the body; and the shrinkage of the scope of the sacred. This is not to argue that people lack survival strategies when dealing with death, but that these strategies become increasingly precarious and problematic in the conditions of high modernity.
Summary1. Culicoides biting midges are vectors of internationally important arboviruses including bluetongue virus (BTV). The ecological constraints imposed by the small body size of these insects strongly influence the epidemiology of the diseases they can carry. Bluetongue virus recently emerged in northern Europe, and atmospheric dispersion models have subsequently been employed to simulate vector movement (and hence likely spread of BTV). The data underlying such models, however, have hitherto either been obtained from small-scale studies or from outside the northwestern Palaearctic. 2. The effects of seasonality and local meteorological conditions upon the daily presence and abundance of Culicoides vectors were examined using 2760 samples collected across a network of 12 different habitat types in England during 2008. Over 50 000 individuals were estimated to be in the samples with males constituting 62% of the total collection, allowing straightforward comparison between potential vector species in terms of their activity rates and seasonality. Culicoides abundance was linked to livestock density and land use. Farm-associated Culicoides species were recorded at all sites including species thought to be restricted to this ecosystem by larval habitat, suggesting a greater potential for dispersal over land than previously thought. 3. Synthesis and applications. The model developed has already been applied in a functional dispersion model to predict disease risk from wind-borne infected Culicoides incursion into the UK and elsewhere. The study has expounded the long-distance dispersal potential of Culicoides, essential for future prediction of the incursion and spread of Culicoides-borne pathogens. It has additionally contributed to the understanding of the ecology of highly dispersive insect vectors.
Transmission of bluetongue virus (BTV) by a vector species of Culicoides was studied using immunohistochemistry, virus titration and in vitro transmission tests. Adult female C. variipennis were used from two colonies that are either "transmission competent" or "transmission refractory" after oral infection with BTV. Intrathoracic (i.t.) injection of BTV into the haemocoel always resulted in a fully disseminated infection and transmission of virus in saliva. However, after ingestion of an infectious blood meal, only 30% (approximately) of midges from either colony became persistently infected. Although none of the orally infected insects from the "refractory" colony were able to transmit virus, 12% of those from the "competent" colony (containing > or = 10(3.0)TCID50 of virus/midge) did transmit BTV in their saliva. The most important barriers to BTV transmission in Culicoides vector species appeared to be a mesenteron infection barrier (MIB), which controls initial establishment of persistent infection, a mesenteron escape barrier (MEB) which can restrict virus to gut cells and a dissemination barrier (DB) which can prevent virus which enters the haemocoel from infecting secondary target organs. Culicoides variipennis do not appear to present either a salivary gland infection barrier (SGIB), or a salivary gland escape barrier (SGEB) to BTV.
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