Alkhurma virus is a member of the Flaviviridae virus family (class IV) so has a positive sense single stranded RNA genome and the virus will replicate in the cytoplasm of the infected host cell. It has been shown to be a variant of the Kyasanur Forest disease virus (KFDV) as it shares 89% nucleotide sequence homology. The virus genome is able to mimic mRNA in host cells and so can use some of the host cells enzymes and machinery for its own gene expression, the virus encodes a single polyprotein which is cleaved to form mature proteins.
This virus was first isolated in Saudi Arabia in the 1990s and since then there have been 24 reported cases, mainly occurring among butchers, with the fatality rate around 25%. It causes a type of tick-borne haemorrhagic fever with the symptoms including fever, headache, joint pain, muscle pain, vomiting and thrombocytopenia which lead to haemorrhagic fever and encephalitis which can result in death. Camels and sheep are the natural hosts of this virus but it is not yet known if other mammals are also involved in its life cycle. There appears to be more than one possible route of transmission seen in people who have become infected with this virus. These are a bite by an infected tick, ingestion of unpasteurised camel milk or entry via a skin wound.
- Low diversity of Alkhurma hemorrhagic fever virus, Saudi Arabia, 1994-1999. Emerg Infect Dis. 2005 May;11(5):683-8. Charrel RN, Zaki AM, Fakeeh M, Yousef AI, de Chesse R, Attoui H, de Lamballerie X.
- Complete coding sequence of the Alkhurma virus, a tick-borne flavivirus causing severe hemorrhagic fever in humans in Saudi Arabia. Biochem Biophys Res Commun. 2001 Sep 21;287(2):455-61 Charrel RN, Zaki AM, Attoui H, Fakeeh M, Billoir F, Yousef AI, de Chesse R, De Micco P, Gould EA, de Lamballerie X.