When the Schmallenberg virus (SBV) made its debut on the European arena, in late 2011, Netherlands and Germany were the first to witness and report it, initially as a clinical event in adult dairy cattle discovered close to the German/Dutch border. The clinical signs, starting in August 2011, were mild and included hyperthermia, drop in
milk production and, in some cases, also diarrhea and abortions. In November 2011, by means of a metagenomic approach, for the 1st time the Friedrich-Loeffler Institute (Germany) detected viral RNA belonging to a new virus in blood samples from clinically affected dairy cows. This new virus was called Schmallenberg virus after the place of origin of the collected samples. Phylogenetic analysis revealed that SBV belongs to the genus _Orthobunyavirus_ within the family Bunyaviridae_.
Ortobunyaviruses are widely distributed in the world; mainly in Asia, Africa, Australia, and Oceania, in tropical and subtropical areas, with a warm and humid climate. Their occurrence depends primarily on the presence of _Culicoides_ spp vector and a reservoir for the virus, which are diseased and infected animals. In Europe, since the 1st
cases of SBV infection in 2011 until September 2013, the presence of SBV or specific antibodies were detected in 27 European countries, including 23 EU Member States (Austria, Belgium, Czech Republic, Croatia, Denmark, Estonia, Finland, France, Hungary, Germany, Ireland, Italy, Latvia, Lithuania, Luxembourg, Netherlands, Poland, Romania, Slovenia, Spain, Sweden, United Kingdom, and Greece) and 4 non-Member
States (Switzerland, Norway, Russia, and Serbia). SBV infection was detected mainly in cows and sheep. Most affected farms were in France and Germany. SBV genome has been detected in bull semen; it remains to be clarified, however, whether the infection can be transmitted to dams by insemination.
SBV is not included in OIE's list of reportable diseases, but was reported as an emerging disease. No human health hazard by SBV has been detected to the present day.
The vector (_Culicoides_ spp) activity season is similar to that of bluetongue virus, starting in the summer until the cooler months. Since the current cases will affect young susceptible animals only, the dimensions of the event are expected to be limited though its spread may include additional countries in north and central Europe.
A useful presentation is available.