Scientists confirm Schmallenberg spread by midges
Belgian scientists believe they have discovered conclusively that biting midges spread the Schmallenberg virus. The virus, which causes deformed and stillborn lambs and calves, has been confirmed in 209 farms across the UK.
Scientists examining the virus in Belgium have found out that biting midges, the same that transmit bluetongue in Europe, are the culprits.
Researchers at the Antwerp Institute of Tropical Medicine (ITG) and the Belgian Veterinary and Agrochemical Research Centre (VAR) have discovered three species of midge that can carry the virus.
Working together, they found the virus can be transmitted from animal to animal via three species of midge – Culicoides obsoletus, Culicoides dewulfi and Culicoides pulicaris.
All three viruses are native to Britain. Culicoides obsoletus is widespread on UK farms. This species of midge was responsible for the spread of bluetongue in 2007, when infected midges were blown across the channel, devastating thousands of livestock.
ITG scientists determined the species of each midge by using a “micro-array”, a molecular technology that can be used by non-specialists to identify midges.
They decapitated the midges and gave only the heads to their colleagues at the VAR centre, who had molecular analytical technology to detect the virus.
Scientists were able to detect the Schmallenberg virus in the saliva of the three midges, which suggests that the virus can be transmitted by biting.
Researchers at the Institute of Animal Health (IAH), in Pirbright, Surrey, are currently testing the Schmallenberg virus on midges. They hope to release some of the findings of their work next month.
Dr Simon Carpenter, the institute’s research leader in entomology, told the Daily Telegraph: “The fact that virus genetic material has been isolated from these midge species is bad news for us in the UK as they are abundant on all of our farms.
“All three of these midges are pretty common here in the UK. Culicoides obsoletus is probably the most abundant species on British farms.”
A DEFRA spokesman said: “European research has confirmed the Schmallenberg virus is spread by midges, as we suspected. We continue to believe the cases currently being reported are as a result of infection late last year.
“Symptoms are not seen in adult animals – sadly it is only when they give birth to deformed young that we know they have been affected. As this is a new disease it is vital farmers and their vets are provided with as much information as possible to help them decide if and what measures they want to take.”
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