From 1 January through 25 February 2018, 1081 suspected cases and 90 deaths have been reported from 18 states (Anambra, Bauchi, Benue, Delta, Ebonyi, Edo, Ekiti, Federal Capital Territory, Gombe, Imo, Kogi, Lagos, Nasarawa, Ondo, Osun, Plateau, Rivers, and Taraba). During this period, 317 cases have been classified as confirmed and eight as probable, including 72 deaths (case fatality rate for confirmed and probable cases = 22%). A total of 2845 contacts have been identified in 18 states.
Fourteen health care workers have been affected in six states (Benue, Ebonyi, Edo, Kogi, Nasarawa, and Ondo), with four deaths (case fatality rate= 29%). As of 18 February, four out of the 14 health care workers were confirmed positive for Lassa fever.
Lassa fever case management centers are operational in four states (Anambra, Abakaliki, Edo, and Ondo States). The health care workers working in these centers are trained in standard infection control and prevention (IPC) as well as use of personal protective equipment (PPE). In addition, the suspected cases and deaths reported in community settings are being actively investigated by the field teams and contacts are being followed up. Currently, three laboratories are operational and testing samples for Lassa fever by polymerase chain reaction (PCR). WHO continues to support the outbreak response, mainly in the domains of enhanced surveillance, contact tracing, strengthening of diagnostic capacity and risk communication.
Lassa fever is endemic in the West African countries of Ghana, Guinea, Mali, Benin, Liberia, Sierra Leone, Togo and Nigeria. As of 22 February 2018, 10 suspected cases who fell ill in Nigeria were reported in Benin, and confirmed cases have been reported from Beninese states that border Nigeria. The outbreak of Lassa fever is considered active in one Nigerian state that borders Benin and two that border Cameroon. Lassa fever is not considered endemic in Cameroon and no outbreaks of Lassa fever have been reported in recent years.