1. Situation update
An outbreak of Ebola Virus Disease (EVD) in West Africa, with onset in December 2013, has rapidly evolved from the epicentre of Guékédou in the forested area of south-eastern Guinea to affect 5 additional areas, including the capital, Conakry, as well as Liberia, Mali and Sierra Leone. Sequencing and phylogenetic analysis has shown that the ebolavirus causing this outbreak is a strain of Ebola Zaire, the most virulent of the ebolavirus species with case fatality rates of 60-90%. This is the first outbreak of EVD in West Africa (except for a single case of Ebola Côte d’Ivoire in 1994) and the first time EVD has affected cities. As of 16 April 2014, the Ministry of Health in Guinea has reported a cumulative total of 197 clinically compatible cases, including 122 deaths, of which 101 are laboratory confirmed by PCR. Guinea has reported 23 clinical cases in health care workers (18 laboratory confirmed and 5 probable cases, with 13 deaths). The date of onset of the most recent cases in Guinea is 15 April.
The Ministry of Health and Social Welfare (MOHSW) of Liberia has reported a cumulative total of 6 laboratory confirmed cases and 21 suspected and probable cases of Ebola Virus Disease (EVD). In Liberia, 13 deaths are being attributed to EVD while awaiting laboratory results.
Sierra Leone has enhanced its surveillance and prevention activities for viral haemorrhagic fevers following the death of 2 probable cases of EVD in one family who died in Guinea and their bodies repatriated to Sierra Leone. Mali had previously reported a cumulative total of 8 suspected cases, all of whom have tested negative for EVD.
As the incubation period for EVD can be up to three weeks, it is likely that the Guinean and Liberian health authorities will report new cases in the coming weeks and additional suspected cases may also be identified in neighbouring countries.
As this is a rapidly changing situation, the number of reported cases and deaths, contacts under medical observation and the number of laboratory results are subject to change due to enhanced surveillance and contact tracing activities, ongoing laboratory investigations and consolidation of case, contact and laboratory data.