The Ebola virus was first identified in a western equatorial province of Sudan and in a nearby region of Zaire in 1976 after significant epidemics in Yamkubu, northern Zaire, and Nzara, southern Sudan. Between June and November 1976 the Ebola virus inf ected 284 people in Sudan, with 117 deaths. In Zaire there were 318 cases and 280 deaths in September and October. An isolated case occurred in Zaire in 1977, a second outbreak in Sudan in 1979. In 1989 and 1990, a filovirus, named Ebola-Reston, was isola ted in monkeys being held in quarantine in a laboratory in Reston (Virginia), Alice (Texas) and Pennsylvania.
In the Philippines, Ebola-Reston infections occurred in the quarantine area for monkeys intended for exportation, near Manila. A large epidemic o ccurred in Kikwit, Zaire in 1995 with 315 cases, 244 with fatal outcomes. One human case of Ebola haemorrhagic fever and several cases in chimpanzees were confirmed in CĂ´te d'Ivoire in 1994-95. In Gabon, Ebola haemorrhagic fever was first documented in 19 94 and recent outbreaks occurred in February 1996 and July 1996. In all, nearly 1,100 cases with 793 deaths have been documented since the virus was discovered. The natural reservoir of the Ebola virus seems to reside in the rain forests of Africa and Asi a but has not yet been identified.