Epidemiological update: Outbreak of Ebola virus disease in West Africa
An outbreak of Ebola virus disease (EVD) with onset in early February 2014 continues to evolve in West Africa. This is the first such outbreak in the region. Two countries, Guinea and Liberia, have reported confirmed cases. The first cases were reported from the forested region of south-eastern Guinea in Guéckédou prefecture near the border with Liberia and Sierra Leone. Results from sequencing of part of the outbreak virus’ L-gene has shown that it is 98% homologous with an Ebola virus last reported in 2009 in Kasai-Occidental Province of the Democratic Republic of Congo.
Background
An outbreak of Ebola virus disease (EVD) with onset in early February 2014 continues to evolve in West Africa. This is the first such outbreak in the region. Two countries, Guinea and Liberia, have reported confirmed cases. The first cases were reported from the forested region of south-eastern Guinea in Guéckédou prefecture near the border with Liberia and Sierra Leone. Results from sequencing of part of the outbreak virus’ L-gene has shown that it is 98% homologous with an Ebola virus last reported in 2009 in Kasai-Occidental Province of the Democratic Republic of Congo.
Update as of 9 April 2014
Guinea: There are 158 officially reported EVD cases, including 101 deaths (case fatality ratio 64%) in Guéckédou (93 cases, 66 deaths), Macenta (21 cases, 15 deaths), Kissidougou (6 cases, 5 deaths) Dabola (4 cases, 2 deaths), Dinguiraye (2 cases, 1 death), Conakry (30 cases, 13 deaths). Fifteen of the cases are healthcare workers, of which at least eight have died. Sixty-six of the cases are laboratory confirmed. Of the remaining clinical cases, 87 are classified as probable cases and four as suspected cases. Eight of the cases have recovered. The date of onset of the most recently identified suspected clinical cases in Conakry and Guéckédou was 8 April 2014. Medical observation is continuing for 488 contacts, while 453 have been discharged from follow-up. No new contacts were identified since 8 April.
Liberia: The Ministry of Health and Social Welfare of Liberia has so far reported 25 EVD cases, including 12 deaths (case fatality ratio 48%). Cases and deaths are reported from Lofa (10 cases, 9 deaths), Margibi (6 cases, 1 death), Bong (4 cases), Nimba (3 cases, 1 death), Montserrado (1 case, 1 death) and Grand Cape Mount (1 case). At present, 32 contacts remain under medical observation. The laboratory-confirmed cases occurred in Lofa County (4) and Margibi County (1). All were fatal. The date of onset of the most recent confirmed case is 6 April. Six patients are currently hospitalised.
Mali: Mali has reported six suspected cases which are currently being investigated. Two previously suspected cases have been discarded after they tested negative for ebolavirus and other viral haemorrhagic fever viruses in assays conducted by the US Centers for Disease Control and Prevention.
Sierra Leone: Two previously suspected cases have been discarded after testing positive for Lassa fever, a disease that is endemic in the country.
There are no suspected or confirmed cases reported in other West African countries.No cases have been detected in returning travellers in Europe.Control activities supported by WHO, UNICEF, Médecins Sans Frontières and other stakeholders are being implemented, including contact tracing, enhanced surveillance and strengthening of infection control practices, free-of-charge access to healthcare for suspected cases, case isolation and management, and social mobilisation. Information and education materials have been developed and distributed, intensive multimedia communications are underway and psychosocial support is being provided to patients, their families and the affected communities. There is ongoing training for carers in safe practices and for members of local communities in safe burials. A team of EU scientists have set up a field laboratory to test suspect cases, working alongside Médecins Sans Frontières at an isolation centre near the borders with Sierra Leone and Liberia.
