Rift Valley fever is considered to be one of the most important viral zoonoses in Africa. In 2000, the Rift valley fever virus spread to the Arabian Peninsula and caused two simultaneous outbreaks in Yemen and Saudi Arabia.
It is transmitted to ruminants and to humans by mosquitoes. The viral agent is an arbovirus, which belongs to the Phlebovirus genus in the Bunyaviridae family.
This family of viruses comprises more than 300 members grouped into five genera: Orthobunyavirus, Phlebovirus, Hantavirus, Nairovirus, and Tospovirus.
Several members of the Bunyaviridae family are responsible for fatal hemorrhagic fevers: Rift Valley fever virus (Phlebovirus), Crimean-Congo hemorrhagic fever virus (Nairovirus), Hantaan, Sin Nombre and related viruses (Hantavirus), and recently Garissa, now identified as Ngari virus (Orthobunyavirus).
References
Flick R, Bouloy M. Rift Valley fever virus. Curr Mol Med. 2005 Dec;5(8):827-34. PMID: #16375716#