Phylogenetics and vector competence of a bovine ephemeral fever virus strain from Israel

Abstract

Bovine ephemeral fever virus (BEFV) [Family Rhabdoviridae: genus Ephemerovirus] causes a transient febrile illness in cattle that results in economic losses and morbidity, with occasional mortality. Epidemics of the disease have been particularly costly in countries of the Middle East, including Israel. The virus is considered a vector-borne pathogen although the exact relationship with a number of blood-feeding arthropods has not been established. In order to improve developments in diagnostic detection, phylogeographic investigations and virus-vector relationships of BEFV we have derived the first genome of this virus from an isolate from Israel and used this to assess recent outbreaks of disease. We have also investigated the vector competence of BEFV with a number of target arthropod species. The complete genome sequence of BEFV (Israel strain 1) is 14 850 base pairs in length and shows over 95 % identity with the only other Middle Eastern genome for BEFV from Turkey. A wider phylogeny shows that these viruses form a clade, previously described as cluster II, which is clearly distinct from BEFV strains derived from China, Japan and Australia. However, there is a distinct separation of those viruses from Israel to others in the Middle East. Preliminary vector competence studies suggest that at least three species of mosquito that are potential transmission vectors of the virus are incapable of infection with, or transmission of, BEFV. Current studies are ongoing to assess other blood-feeding insect species as potential vectors.