The International Scientific and Technical Committee, established by the World Health Organization (WHO) in Zaire, officially announced today the end of the recent outbreak of Ebola haemorrhagic fever in this country. Dr Ebrahim M. Samba, WHO Regional Director for Africa was present at the ceremony.

The last identified case was admitted to hospital in Kikwit on 24 June 1995 and was discharged on 14 July 1995. Since two maximum incubation periods, that is 42 days, have elapsed without any new reported cases, the conditions allowing the outbreak to be officially declared over are now met.

Active surveillance and tracing of cases and deaths retrospectively have shown that the first identified case related to the outbreak had onset of illness on 6 January 1995.

The final total of confirmed cases is 315, including 244 deaths, which represents

a mortality rate of 77%. One hundred sixty-six of the 315 cases were females and 149 males. Mortality is slightly higher among males (81%) than among females (74%).

The cases ranged in age from 3 days to 71 years, with a median of 35 years. Twenty six cases were less than 17 years old and 13 were over 60 years old. The median age among survivors was 29 years, among fatal cases 35 years.

Of the 286 cases with known professional occupation, 75 (26%) were nurses or students, 61 (21%) housewives. Retrospective case-finding is going on to assess the full magnitude of this outbreak.

The cases have occurred in three Sub-Regions of Bandundu Region, with one case in the Kwango Sub-Region and the rest in Sub-Regions Kikwit and Kwilu. Two hundred sixty-six cases have been reported in Kikwit, the remaining in Bulungu (13 cases), Fashi (1), Gungu (4), Idiofa (1), Mosango (23) Mokala (1) and Vanga (6).

Since the reservoir of the virus is not known, during the outbreak and subsequent studies, field teams captured more than 3000 birds and mammals, including small rodents, and several thousands possible insect vectors. Samples from these animals is now being processed for virus isolation.

Blood samples from patients, patient contacts and health care workers potentially exposed are being investigated in the WHO collaborating Centre for Reference and Research on Special Pathogens at the Centers for Disease Control and Prevention, Atlanta, Georgia, USA, and in the WHO Collaborating Centre for Reference and Research on Haemorrhagic Fevers and Arboviruses at the National Institute of Virology, Johannesburg, South Africa.