Changes

Introduction of bluetongue virus to a new area has the potential to occur in several ways. Firstly, infected animals may be transported to the region, and local insect vectors could spread and perpetuate BTV infection within naive animals. It is also possible that local vectors could acquire BTV from infected animals in neighbouring areas, where there is a cross-over in the distribution of ''Culicoides'' species. Finally, infected vectors can be acquired from areas where bluetongue infection exists. ''Culicoides'' can be transported considerable distances on the wind, and it is also conceivable that the distribution of competent vectors may expand to colonise previously unpopulated areas under the influence of climate change.

Introduction of bluetongue virus to a new area has the potential to occur in several ways. Firstly, infected animals may be transported to the region, and local insect vectors could spread and perpetuate BTV infection within naive animals. It is also possible that local vectors could acquire BTV from infected animals in neighbouring areas, where there is a cross-over in the distribution of ''Culicoides'' species. Finally, infected vectors can be acquired from areas where bluetongue infection exists. ''Culicoides'' can be transported considerable distances on the wind, and it is also conceivable that the distribution of competent vectors may expand to colonise previously unpopulated areas under the influence of climate change.

Bluetongue virus infection was first confirmed in the UK in September 2007 when a veterinarian spotted suspicious clinical signs on a cattle holding near Ipswich⁸. It is believed that BTV-laden vectors were dispersed to the UK on the wind, since meteorological conditions on 4th August 2007 were capable of carrying midges from northern Europe to East Anglia. This would be expected to produce disease at a point that would coincide with the first case, given the time necessary for clinical detection to occur.

Bluetongue virus infection was first confirmed in the UK in September 2007 when a veterinarian spotted suspicious clinical signs on a cattle holding near Ipswich⁶. It is believed that BTV-laden vectors were dispersed to the UK on the wind, since meteorological conditions on 4th August 2007 were capable of carrying midges from northern Europe to East Anglia. This would be expected to produce disease at a point that would coincide with the first case, given the time necessary for clinical detection to occur.

==Pathogenesis==

==Pathogenesis==