Detection of Schmallenberg virus in Culicoides species of the Obsoletus complex in Germany

Malformed lambs were born on an animal husbandry station in Brandenburg, Germany in January 2012 with signs typical of a Schmallenberg virus (SBV) infection such as torticollis, arthrogryposis and inferior brachygnathia. Infections with SBV were confirmed by post-mortem and laboratory diagnosis. This finding prompted us to retrospectively investigate the eventual presence of SBV in insects collected on pastures of the farm during 2011 while conducting two entomological studies. Insects were collected at dusk with a drop trap from cattle in the first study (16 May - 8 July 2011) and from sheep in the second study (19 September - 5 October 2011) and stored in 70% ethanol. Genome sequences of SBV were detected by a real time quantitative reverse transcription PCR (RT-qPCR) in a pool of biting midges belonging to the Culicoides obsoletus complex that were caught in the week of 26 September 2011. All pools of Aedes and Culex mosquitoes and the Culicoides spp. collected during the first study in May-July 2011 tested negative.