A novel virus, affecting ruminants, found in Europe


<p>In autumn 2011, a hitherto unknown cattle virus was detected in Germany; more recently, it has also been found in the Netherlands and Belgium. The virus also affects sheep and goats. The Schmallenberg virus belongs to the Orthobunyavirus genus, a group of viruses transmitted from animal to animal by insect vectors. In particular, malformations in newborn lambs have been detected, which appear to be caused by this virus. It is unlikely that the virus affects humans.</p>

How was the new virus found?

In August/September, symptoms pointing to a contagious disease were noted in German dairy cattle. The cows suffered from a fever, general indisposition and lack of appetite, as well as a significantly reduced milk yield. Recovery took several days per animal. Similar symptoms were also reported in the Netherlands and Belgium.

Since the symptoms were not caused by any known pathogen, novel molecular biological methods were applied to identify the unknown cause of the disease. In November, the German Friedrich Löffler Institute (FLI) reported the identification of a new cattle virus, named the Schmallenberg virus after its location of discovery. The new PCR method employed in the identification of this virus was developed in Germany.

What is known about the virus?

The Schmallenberg virus belongs to the Orthobunyavirus genus, a group of viruses transmitted by mosquitoes and Culicoides biting midges. Its closest relatives are the Akabane, Aino and Shamonda viruses, all of which affect ruminants. Most significant among these is the Akabane virus, which causes malformations of the same types now found in lambs: stiff or deformed joints, crooked necks and backs as well as serious deformations of the brain (hydrocephaly and underdeveloped brains). After a regular full-term pregnancy, the lambs were either stillborn or died shortly after birth. Deformed calves are expected later in the spring. The virus's pathogenic capabilities are currently under examination and the development of diagnostics, including methods for detecting antibodies and developing a vaccine, is under way.

Where has the virus been found?

So far, the Schmallenberg virus has been reported in Germany, the Netherlands and Belgium. In that region, infection was spread by biting midges during August/September 2011. The area has the densest population of ruminants in Europe. It was here that the Bluetongue virus – which is also carried by culicoides midges – was first found in August 2006. At the moment, inactivity among midges makes the spread of the disease unlikely. Only in Australia and Japan has the closely related Akabane virus caused regular outbreaks of disease, although it also exists in Cyprus, the Middle East, Asia and Africa. Based on current information, it seems unlikely that the disease will spread to Finland.

Report deformations!

It is important to notify the municipal veterinarian of any lambs, kids or calves born with deformations. If farmers suspect that their animal show signs of the disease, they are also obliged to contact the municipal veterinarian.

Evira is monitoring the animal disease situation in Europe.

Further information on the subject:
Standing Committee on the Food Chain and Animal Health (SCFCAH)
European Centre for Disease Prevention and Control 

For further information, please contact:
Ulla Rikula, Senior Researcher, Veterinary Virology Research Unit,
tel. +358 50 563 2052

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