Ebola virus (EBOV, formerly designated Zaire ebolavirus) is the sole member of the Zaire ebolavirus species, and the most dangerous of the five known viruses within the genus Ebolavirus. Four of the five known ebolaviruses cause a severe and often fatal hemorrhagic fever in humans and other mammals, known as Ebola virus disease. The virus and its species were both originally named for Zaire (now the Democratic Republic of Congo), the country where it was first described, and was at first suspected to be a new "strain" of the closely related Marburg virus; the virus (but not its species) was renamed to "Ebola virus" in 2010 to avoid confusion.
The EBOV genome is approximately 19.000 base pairs long. It encodes seven structural proteins: nucleoprotein (NP), polymerse cofactor (VP35), (VP40), GP, transcription activator (VP30), VP24, and RNA polymerase (L). It is difficult to study due to the virulent nature of the virus. Ebola virus is one of the four ebolaviruses known to cause disease in humans. It has the higest case-fatality rate of these ebolaviruses, averaging 83% since first described in 1976, although fatality rates up to 90% have been recorded in one epidemic (2002-03).
