Ebola is the common term for a group of viruses belonging to genus Ebola, family Filoviridae, and for the disease which they cause, Ebola hemorrhagic fever. The viruses are characterised by a long, filamentous morphology surrounded by a protein/lipid viral envelope. Ebola viruses are morphologically similar to the Marburg virus, also in the family Filoviridae, and share similar disease symptoms. Ebola has caused a number of serious and highly publicized outbreaks since its discovery.