Schmallenberg virus infection in small ruminants – First review of the situation and prospects in Northern Europe

Mid November 2011 a new virus, provisionally named Schmallenberg virus was detected in serum samples from dairy cattle with short febrile episodes, milk yield drop, and diarrhoea, using virus isolation and real-time quantitative reverse transcription PCR (RT-qPCR). December 2011, brain tissue samples of congenitally malformed lambs were diagnosed as positive. Schmallenberg virus most likely belongs to the Simbu serogroup of the genus Orthobunyavirus of the family Bunyaviridae and is arthropod-borne. Similar viruses can be found worldwide, but occurrences are rare in Europe. Malformations included arthrogryposis, torticollis, scoliosis and kyphosis, brachygnathia inferior, and mild-to-marked hypoplasia of the cerebrum, cerebellum and spinal cord. Prevention and control is complicated as suitable tools are not yet available. Although zoonotic implications are negligible, further seroepidemiological studies are warranted. Schmallenberg virus infections can have a comprehensive effect on production and substantial economic impact, depending on time of infection and prevalence.