Molecular and reverse genetics studies of orbivirus transmission host responses epidemiology and diagnostic systems

Since 1998, there have been multiple incursions of bluetongue into Southern, Central and Northern Europe. These outbreaks have involved at least 12 distinct bluetongue virus (BTV) strains, belonging to 9 different serotypes and have lead to the death of more than two million animals. In addition, significant economic losses have been incurred due to loss in productivity, restrictions in animal movements and trade as part of control programmes. These events demonstrate that the entire European Union is now at risk from further introductions of BTV, and potentially of other BTV-related related Orbiviruses, particularly those also transmitted by Culicoides vectors (including African horse sickness virus [AHSV], epizootic haemorrhagic disease virus [EHDV] and equine encephalosis virus [EEV]). Worryingly, AHSV, EHDV and EEV have been detected just outside the EU in Israel, Turkey, as well as North and West Africa and now pose a further significant threat to livestock in Europe. This proposal will establish 'OrbiNet', a network of 9 laboratories focussing on research on BTV and related orbiviruses in 8 European countries and Israel. The 'OrbiNet' Partners include university departments, government laboratories and reference centres that already work on orbiviruses and associated diseases. The goals of OrbiNet are to provide training, share reagents and expertise, and conduct targeted research programmes with the overall aim to better understand orbivirus transmission, epidemiology, pathogenesis and develop better diagnostic techniques. These activities will enhance research capacity and capability and increase the knowledge base and expertise within partner laboratories, thus underpinning the development of improved tools / strategies to prevent and control these economically important animal pathogens. OrbiNet will closely liaise with the scientific community, government agencies, the EU and industry in order to exploit the knowledge generated and help to inform animal health research policies and activities at the EU level.

'OrbiNet' will build a network of research laboratories across 8 European countries and Israel, focussing on bluetongue and other important diseases (including epizootic haemorhagic disease and African horse sickness) that are caused by closely related orbiviruses. The Partners include university departments, government laboratories and reference laboratories that are already established as research centres for these important and emerging pathogens. The OrbiNet coordinator, Prof. Peter Mertens, (IAH Pirbright) has 29 years BTV research experience, and is well suited to steer the network. The Principal Investigators have established and complementary expertise in molecular virology, pathogenesis, epidemiology, viral diagnostics, virus structure, vaccinology and immunology, with access to appropriate resources, facilities and reagents to meet project goals. WP leaders will meet every 6 months to monitor progress and help co-ordinate specific aspects of the programme. Exchange visits between participating laboratories, training modules, and joint meetings / publications will help disseminate results of the work carried out and cement long term relationships.

The spread of BTV has had a major impact on sustainability and productivity of livestock industries across Europe. It has restricted and damaged trade between European Member states, caused major animal health losses associated with fatalities, reduced productivity and associated surveillance control programmes. BTV has been introduced on many occassions to both Southern and Northern Europe, resulting in major disease outbreaks, demonstrating that the disease poses a continuing risk to the region and indicating an increased risk posed by related orbiviral diseases transmitted by the same insect vectors. The importance of research in these areas is highlighted by the success of molecular epidemiology studies, novel assays and vaccination programmes particularly against BTV-1 and 8. However, it is clear that there is still room for further improvement in diagnostic systems, as well as a better understanding of the molecular mechanisms and genetic determinants of the host's immune response to the virus, determinants of virus transmission by the insect vector, overwintering, transplacental transmission, pathogenesis and virulence. Further detailed information in these areas will help us assess risks and develop better control strategies for bluetongue and related diseases.