What is the Schmallenberg Virus?
The Schmallenberg virus is a newly emerging virus in the same family as the Akabane virus. Little is known about it, but new information is coming to light daily. As it is a new virus testing is still being developed and a vaccine is a long way off.
The virus appears to be spread by biting insects most likely midges (similar to bluetongue), however, direct transmission may also occur. Acording to Met office data there were 4-8 days in August to late October when infected midges could have been blown across the channel. Thus disease is emerging now but infection actually took place last year.
It appears that animals which are bitten by infected insects are highly likely to contract the disease, and subsequent insects biting this animal are highly likely to become infected themselves. Spread of the disease therefore is a lot quicker and easier than we have seen with bluetongue.
What does it do?
The clinical signs of Schmallenberg virus seem to primarily be seen in the foetus. These clinical signs consist of severe brain damage/deformities if infection occurs in the first third of pregnancy, limb deformities if infection occurs in the middle third of pregnancy, and brain problems presenting as depression, problems standing/balancing, and inability to suckle if infection occurs in the last third of pregnancy.
Infection in the animal usually has no symptoms at all, although in cattle it may present as diarrhoea, high temperature, and reduced milk yield.
Newborn animals that are affected may or may not be viable, whether the viable effected offspring are a disease risk to other animals is not known, it would be wise to separate any affected offspring with their dam, from the rest of the flock/herd.
At the present time infection has only been confirmed in sheep, but all ruminants are susceptible. Infection rates are variable, but up to 50% of offspring can be affected.
Can it infect humans?
Some viruses in the same family as this can infect humans but it seems Schmallenberg lacks the required genes. Having said this we would recommend women who are pregnant or hoping to become pregnant should not come into contact with ruminant animals, especially around lambing/calving/kidding.
What should I do?
At present the disease is not notifiable, but we encourage you to report any birth abnormalities to us at Three Rivers & Chapelfield Farm Vets.
The DEFRA website is updated daily with all the latest information, so this is a good place to start if you have questions or concerns.