Schmallenberg virus: emergence of an Orthobunyavirus among ruminants in Western Europe

Abstract

Recently, a novel virus has been identified among ruminants in Western Europe. This virus, the so-called Schmallenberg virus, belongs to the family Bunyaviridae, genus Orthobunyavirus, serogroup Simbu and is closely related to Akabane, Aino and Shamonda virus. In cattle, acute symptoms in the dam and adult animals generally include high fever, milk drop and diarrhea. More importantly, infection during gestation may lead to abortion, stillbirth and congenital malformations. As all bunyaviruses, Schmallenberg virus also uses vectors for efficient transmission. Closely related viruses causing similar symptoms, such as Akabane and Akabane- like viruses, are mainly transmitted by Culicoides. It is very likely that Schmallenberg virus is transmitted by similar vectors. This review provides an overview of Bunyaviridae, their epidemiology, symptoms, prevention and control. Special emphasis is put on the Simbu serogroup of the Orthobunyavirus genus pointing out the similarities between them and closely related members.