The Met Office is working closely with the Institute for Animal Health (IAH) at Pirbright, Defra and the Animal Health and Veterinary Laboratories Agency (AHVLA) to provide advice on the possible wind-borne spread of the Schmallenberg Virus.
It is believed that the virus is carried by midges. Although the prevailing winds in Britain are from the southwest, conditions are right for a few days a month for midges to be blown across the North Sea from areas where infection has been recorded and into the eastern and southern counties.
We have been using our atmospheric dispersion model, NAME, to determine if there were any suitable occasions for infected midges to be blown from the near continent to UK.
The NAME model had been previously adapted to model wind-borne Culicoides midges to simulate the spread of bluetongue virus. It was used during the first outbreak of bluetongue in the UK in 2007 and helped in the design of targeted vaccination policies during 2008 to prevent further outbreaks.
Since bluetongue, we have been monitoring warm spells over Europe between April to November, and factoring in sunny and warm days when midges would take off. For the current Schmallenberg Virus outbreak we compiled an assessment of the highest risk areas of the UK from July to November 2011. This highlighted that all south east, south and south west coastal counties from Norfolk to Cornwall were at risk of exposure to windborne Culicoides midges from infected areas of the continent.
Many uncertainties are associated with this virus and the Met Office will continue to work closely with the AHVLA and Defra to inform their decision making. As further information becomes available, a more detailed meteorological analysis can be carried out.