Bunyaviral diseases of animals (excluding Rift Valley fever and Crimean-Congo haemorrhagic fever) : Chapter 3.10.1

The order Bunyavirales has hundreds of members distributed over 12 families with a large number of genera. Most viruses of the different families are transmitted to vertebrates by arthropods (arboviruses). Members of the family Hantaviridae are not arboviruses. The families of veterinary importance are Nairoviridae, Peribunyaviridae and Phenuiviridae. The genus Orthonairovirus contains the zoonotic Crimean–Congo haemorrhagic fever virus (for which see Chapter 3.1.5) and the ruminant pathogen Nairobi sheep disease (NSD) virus (NSDV). The largest genus, Orthobunyavirus, is subdivided into 103 virus species and 48 serogroups including only a few significant pathogens of animals, among them Cache Valley virus (CVV), Akabane virus (AKAV), Schmallenberg virus (SBV) and Shuni virus (SHUV). These viruses have a tropism for fetal tissues and are responsible for prenatal losses and multiple congenital deformities in domestic ruminants. SBV is a novel Orthobunyavirus that emerged in 2011 in Europe. The virus was found in malformed lambs, kids and calves in different European countries and spread to most parts of Europe. Other members of the order Bunyavirales that are of veterinary importance are Rift Valley fever virus (RVFV), a member of the Phenuiviridae family (genus Phlebovirus), described in Chapter 3.1.18 Rift Valley fever. Members of the Orthonairovirus and Orthobunyavirus genera are enveloped spherical or pleomorphic RNA viruses, 80–110 nm in diameter, with three genome segments (S, M and L) of negative polarity