Farmers are being advised to consider vaccinating their cattle against the Bluetongue virus (BTV-8) due to outbreaks in Europe.

The risk of BTV incursion into UK population remains at LOW (“rare, but could occur”) to reflect the low levels of infection in northern France but there have been 474 BTV-8 positive cases four in France since the end of July. However there has been no expansion of the surveillance zone and no new cases reported from near the French northern coast.

The lack of disease being reported in the north of France is the main risk mitigation factor. Recent meteorological modelling has shown there have been very few days in the last few months where the wind has been sufficiently strong or in the right direction to reach the UK mainland from the areas in France with the highest level of disease circulation.

Switzerland has now reported BTV-8 in cattle in two regions. Single animals tested positive in herds of 90 and 58 cattle and the single animals were both culled. A restriction zone covering the whole country has been put in place to allow free movement of animals around the regions, but exports to other countries must meet certain conditions.

The cases in Switzerland are not a surprise given the proximity to cases in France. Indeed, the authorities had been communicating to farmers to expect cases, to vaccinate their animals and to report any suspicious signs to their vets. Vaccination against BTV-4 and BTV-8 is allowed, but this is a voluntary measure which farmers are encouraged to take.

These cases appear to be a result of vector movement rather than live animal trade and highlight that proximity to affected areas with high levels of virus circulation and cattle density are key factors in disease transmission.

The detection of PCR positive animals in the UK which recently arrived from France from a region with high virus circulation is not confirmation of disease in UK animals. Instead these were picked up as part of the government's post import checks and those animals which represented an animal health risk were culled. This serves as a reminder that if farmers wish to import from any BTV restricted zone, vaccinating their own herd before-hand would be a sensible risk mitigation measure.