Vector-borne Diseases Programme

Since 1998, the disease bluetongue (BT), caused by bluetongue virus (BTV), has entered Europe and has reached significantly further north than ever before anywhere in the world including, for the first time, the UK in 2007. We are identifying the origins, serotypes and spread of the virus in Europe using molecular epidemiological techniques and improved diagnostic assays developed within this programme. These methods are now being used by the World Organisation for Animal Health (OIE) and Community (CRL) Reference Laboratories for BT, located within IAH, to monitor the ongoing incidence and spread of the disease in the UK and elsewhere in Europe. The spread of BTV is driven by on-going climate-change, particularly higher temperatures and extreme weather events (e.g. increase in winds), facilitating its transmission by Culicoides (biting midge) species. Modelling of weather conditions, wind directions and seasonal factors, together with the rapid identification of infected animals, is contributing to the design and targeting of control measures to the animals and locations where they are needed within the UK and elsewhere. Measures include vaccination, insect control, animal movement restrictions and husbandry modifications. The occurrence of BTV-8 in northern Europe has demonstrated that the whole continent is now threatened by further incursions of this and other strains of BTV, and by other, related viruses, such as African horse sickness virus (AHSV), epizootic haemorrhagic disease virus, equine encephalosis virus, and potentially by other arthropod-borne viruses (arboviruses).

The original South African ?live? vaccines that were available for BTV actually cause disease in some breeds of European sheep. With input from this programme, safer ?inactivated? vaccines have recently been developed and tested by the pharmaceutical industry, and are now being marketed and deployed. They appear to be dramatically reducing the otherwise expected intensity of disease in the field. However, to date, inactivated vaccines are only available for a limited range of BTV serotypes, and none are available for any serotypes of the related AHSV. These require development.

For the future it is important to know how far north BTV, AHSV and other important arboviruses, including mosquito-borne diseases that can affect people (zoonoses) (e.g. Rift Valley fever, West Nile disease), might expand at a time of ongoing climate-change, and the risk they will pose to livestock and humans. We are developing improved diagnostics and vaccines, investigating the transmission of the viruses, and the ways in which they survive the winter. We are also investigating vector ecology and vector control, the structure/biochemistry/immunology of the target viruses, and modelling disease outbreaks to help predict, understand and mitigate the risks involved.

 

Programme Leader: Dr Philip Mellor
Deputy Programme Leader: Dr Peter Mertens

The Programme consists of the following Workpackages and Principal Investigators:

WP1 Laboratory transmission studies - Philip Mellor, Simon Carpenter
WP2 Vectorial transmission data - Philip Mellor, Simon Carpenter
WP3 Reference Laboratory -Chris Oura
WP4 Molecular epidemiology, phylogenetics - Peter Mertens, Sushila Maan, Chris Oura
WP5 Structural biology of orbiviruses - Peter Mertens, Houssam Attoui
WP6 Immunology, vaccination strategies - Peter Mertens, Geraldine Taylor
WP7 Modelling transmission of vector-borne diseases - Simon Gubbins, Simon Carpenter
WP8 Insect genomics - Peter Mertens, Houssam Attoui, Simon Carpenter