Windswept midges brought Schmallenberg to UK

The Schmallenberg virus that causes birth defects in sheep and cattle was carried to the UK by midges blown over from French and Belgian farms, say Oxford University scientists. Schmallenberg was first seen in Germany in 2011 and spread rapidly across Europe through Culicoides midges, the same insects that carry the bluetongue virus. The researchers showed that Schmallenberg spreads more widely than is revealed by birth defects and is also highly dependent on wind direction. The model suggests that the disease, which first hit UK farms in 2011, was introduced from across the Channel by infected midges from at least ten farms in France and Belgium. It also shows that around half of infected farms across Europe are 'dead-ends' that do not go on to spread the disease further. These latest findings, published in Scientific Reports , could help farmers and policymakers to understand more about the spread of viruses such as Schmallenberg and plan how best to control them. 'We found that most birth defects in sheep were caused by Schmallenberg infections approximately five to six weeks after conception,' said Dr Luigi Sedda of Oxford University's Department of Zoology, lead author of the paper.