from Peter J. Walker, Kim R. Blasdell and D. Albert Joubert writing in Rhabdoviruses: Molecular Taxonomy, Evolution, Genomics, Ecology, Host-Vector Interactions, Cytopathology and Control:
The genus Ephemerovirus comprises arthropod-borne rhabdoviruses that infect primarily ruminants. They include bovine ephemeral fever virus (BEFV) which is one of the most important vector-borne pathogens of cattle, Berrimah virus (BRMV), Kimberley virus (KIMV) and Adelaide River virus (ARV) which were isolated in Australia, Malakal virus (MALV), Obodhiang virus (OBOV) and kotonkan virus (KOTV) from Africa, and Puchong virus (PUCV) from Malaysia. Ephemeroviruses have similar morphology to other animal rhabdoviruses but have large complex genomes encoding a non-structural glycoprotein (GNS) and several small accessory proteins. BEFV is enzootic in tropical and sub-tropical regions of Africa, Asia and Australia, extending into temperate climes in sometimes extensive epizootics. Clinical signs include fever, nasal and ocular discharge, stiffness, anorexia, rumenal stasis, joint swelling and limb paralysis. BEFV has been isolated from mosquitoes and biting midges (Culicoides spp.) but the specific vectors responsible for transmission are not defined. Disease outbreaks are usually associated with heavy rainfall or conditions that favour the proliferation of insect populations. KOTV also causes an ephemeral fever-like illness but other ephemeroviruses are not known to cause disease. Live-attenuated and inactivated BEFV vaccines are available but require multiple doses and the adoption rate, particularly in extensive beef industries is low.