Ebola Sudan, Ebola Zaire, Ebola Cote d'Ivoire, and Ebola Reston are the four known
strains (subtypes) of Ebola. Ebola and Marburg are the only members of the filovirus
family. Filoviruses (Ebola) are helical, non-segmented, negative, single-stranded
RNA viruses, polymorphic, noninfectious, and have variable lengths.
Infectious Ebola virions are usually 920 nm in length, 80 nm in diameter, and
have a membrane stolen from the host cell by budding. The virus encodes for a
nucleoprotein, a glycoprotein, 7 polypeptides, a polymerase, and 4 other undesignated
proteins. These proteins are made from polyadenylated mRNA transcribed in the
host cell from the virus RNA.
Median unit lengths of EBOR virions range from 1026 to 1083 nm (1)
Other morphological differences amongst the strains remains to
be discovered. They are very difficult to distinguish from each other and are
known to cross-react (2).
References:
Geisbert, T.W. and P.B. Jahrling. "Differentiation of filoviruses by electron
microscopy." Virus Research 39 (1995) 129-150.
Crusberg, Ted. Personal Communication.
Ebola Phylogenetic Tree
Image from Georges-Courbot. "Isolation and Phylogenetic Characterization of
Ebola Viruses Causing Different Outbreaks in Gabon."
