New Orthobunyavirus isolated from infected cattle and small livestock - potential implications for human health : Risk assessment

In early November 2011, a new orthobunyavirus, provisionally named the Schmallenberg virus, was detected by metagenomic analysis and virus isolation from infected cattle in Germany. Similar findings have been reported from the Netherlands, where lambs have also been infected with the same virus in utero, resulting in congenital malformations. Based on current evidence, it is not possible to confirm or exclude a causal relationship between detection of the new orthobunyavirus and the observed clinical symptoms in cattle and small livestock. Epidemiological, immunological and microbiological investigations are ongoing in Germany and the Netherlands. According to health authorities in Germany and the Netherlands, further cases in cattle and small livestock can be expected. Diagnostic capacity is currently limited to a real-time RT-PCR, which has to be further validated. Improved diagnostic methods, including serology, will facilitate identification of newly-affected holdings and geographic areas. Previously, genetically similar orthobunyaviruses have not caused disease in humans. It is therefore unlikely that this virus will cause disease in humans, but it cannot be excluded at this stage. Close collaboration between animal and human health services is necessary to ensure rapid detection of any change in the epidemiology of animals and humans. In particular, the health of farmers and veterinarians in close contact with potentially infected animals should be carefully monitored.