The virus, spread by continental midges, causes birth defects in livestock. Appearing for the first time in the UK this year, it has spread from sheep to affect 30 cattle farms.
Nigel Gibbens, chief veterinary officer with the Department for Environment, Food and Rural Affairs (DEFRA), said: “We are working closely with our partners across Europe to understand more about this new virus and support the farming industry’s efforts in dealing with it. An important part of this is closely monitoring cases of Schmallenberg.
“We’re seeing a relatively limited impact on farms. But, of course, this could change as the lambing and calving seasons continue.”
Peter Garbutt, National Farmers Union chief livestock adviser, told FoodManufacture.co.uk that the virus was unlikely to have a large effect on the food supply chain – but that could change.
If the virus started to spread out of its current localised area in the south east, or if it is discovered that the UK midge population is infected, the impact on the supply chain could be significantly worse, he added.
“There’s no way to predict the extent,” said Garbutt.“It’s a funny virus. Adults do not show much in the way of symptoms aside from a small amount of fever and some drop in milk production. The main symptoms occur in calves and lambs.”
The disease, named after the German town where it was detected last November, has been confirmed on 249 farms in England. The virus has been detected on 32 cattle units and 217 sheep farms, according to the Animal Health and Veterinary Laboratories Agency.
The full extent to which the virus has spread among cattle will not be known until DEFRA completes its lambing and calving survey next month.
No vaccine is available to control the virus. Scientists hope that if domestic midges carry the virus, they could also effectively immunise sheep and cattle before the start of the next lambing and calving seasons, said Garbutt.
Across Europe, the disease infected sheep and cows on 2,600 farms in eight EU countries last year.
Alberto Laddomada, head of the European Commission’s animal health unit, acknowledged that the disease had spread “very, very quickly”.
He told Reuters: “It is certainly a warning for the whole world in the sense that, unfortunately, new threats may emerge.”