EMERGENCE OF SUBTYPE ZAIRE EBOLA-VIRUS IN GABON

Gabon has recently been struck three times by Ebola hemorrhagic fever. The first isolate originating from the 1994 outbreak has been subject ed to molecular characterization of its GP and VP24 genes. Sequence an alysis demonstrates that the agent, Gabon-94 virus, belongs to subtype Zaire of Ebola virus. The isolate is closely related to the Kikwit-95 isolate, and both viruses seem to have evolved from a progenitor viru s different from that of the Zaire-76 isolates. The relatively close r elationship of all subtype Zaire viruses isolated at different geograp hical locations and up to 20 years apart suggests an extreme conservat ion in the yet unknown natural reservoir of Ebola viruses. The level o f genetic variability in the human host might be different as indicate d by the comparison of isolates from a single outbreak (Mayinga-76 and Eckron-76), but needs further investigation on clinical material of p atients by PCR since both isolates have different levels of passages i n tissue culture. (C) 1997 Academic Press.