Control Prevent entry Reduce exposure Vaccination Learn to live with disease

Competent vectors

Contingency plans Developed with core stakeholder group Disparate interests Need to involve all livestock owners Response must be proportionate

Summary of the challenges of BTV Molecular level Continual change in genetic sequence in replication vector and host Re-assortment and genetic drift 24 serotypes – 24 diseases Cell level Avoid host defences within the cell extracellularly Host level Wide variation in virulence of the virus Variation in pathogenicity between species and breeds Vector level Virus factory which can widely disseminate the disease Potential for recruitment of new vector species.

Future challenges Vaccine development e.g. VLP subunit vaccines, killed vaccines Understanding the infection in the midge and host pathogenicity Develop sophisticated control measures base on manipulation of the vector and virus Keeping abreast of changes in sequences and emergence of new strains of BTV so as develop and refine diagnostic tests and epidemiological investigations. Blue tongue virus is a fascinating parasite that manages throught is structure to change and adapt… its success is linked to that of the vector – which ultimately controlled by climate and its genetics – and “competence”. Understanding this virus and its function may lay with the vector rather than animal studies. The structure, the sequences, the variatioin in topotyes, strains and their continual evoluation provides a challenge