Schmallenberg virus activity in cattle in Switzerland in 2013.

SCHMALLENBERG virus (SBV), a novel Orthobunyavirus , was detected for the first time in November 2011 in Germany in blood samples originating from cattle suffering from acute clinical signs such as reduced milk production, high fever and diarrhoea (Hoffmann and others 2012). Viral transmission to domestic and wild ruminants occurs through biting midges. As a consequence of infection, malformations and abortions of newborns in addition to acute clinical signs occurring in adult cattle are described (Doceul and others 2013). The presence of SBV in Switzerland was first demonstrated by the detection of viral RNA in a blood sample from an acutely infected dairy cow in July 2012 (Schorer and others 2012). From then on, a rapid spread of the infection throughout the country and a high seroprevalence of anti-SBV antibodies within the Swiss ruminant population were observed (Balmer and others 2014). No further surveillance projects were performed, and diagnostic investigations were no longer compensated. Thus, knowledge concerning the circulation of infectious virus in Switzerland in 2013 is limited. No indications for acute clinical manifestations in adult cattle or for an increased number of malformations appearing as a consequence were present in 2013. It has to be mentioned that this could be related to the lack of samples due to the altered funding strategy. Recent publications describe the spread and consequences of SBV infection in several European countries (Doceul and other 2013, Dominguez and others 2014, Steinrigl and others 2014, Wernike and others 2014). In contrast, only little information is available on studies investigating SBV circulation in European countries during 2013 following the first intrusions in 2011/2012 …