The Nigeria Centre for Disease Control and Prevention has recorded 143 confirmed cases of Lassa fever out of 484 suspected cases from December 30, 2024, to January 12, 2025, across seven states and 32 local government areas.
The centre also reported 22 deaths, resulting in a Case Fatality Rate (CFR) of 15.4 per cent.
This information was contained in the Lassa fever situation report obtained from the NCDC on Wednesday.
According to the report, the deaths occurred in Ondo (6), Edo (5), Bauchi (2), Taraba (6), Ebonyi (2), and Gombe (1).
The World Health Organisation describes Lassa fever as an acute viral haemorrhagic illness caused by the Lassa virus, a member of the arenavirus family. Humans usually contract the virus through exposure to food or household items contaminated by the urine or faeces of infected Mastomys rats.
The disease is endemic to the rodent population in parts of West Africa and is prevalent in countries such as Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo, and Nigeria. It is also likely present in other West African nations.
“Person-to-person infections and laboratory transmission can also occur, particularly in healthcare settings where infection prevention and control measures are inadequate,” WHO stated.
The NCDC report noted: “In week two, the number of new confirmed cases increased from 54 in epidemiological week one of 2025 to 89, reported in Ondo, Edo, Taraba, Bauchi, Gombe, Kogi, and Ebonyi States.
“Cumulatively in week two of 2025, 22 deaths have been reported with a CFR of 15.4 per cent, which is lower than the CFR for the same period in 2024 (16.4 per cent). Seven states have recorded at least one confirmed case across 32 local government areas this year.”
The report further revealed that 77 per cent of all confirmed Lassa fever cases were from Ondo (38 per cent), Edo (22 per cent), and Bauchi (17 per cent), while the remaining 23 per cent were reported from four other states.
It added that the predominant age group affected is 21–30 years (range: 3 to 78 years, median age: 32 years), with a male-to-female ratio of 1:0.7 among confirmed cases.
The number of suspected cases decreased compared to the same period in 2024, the report noted. One new healthcare worker was affected in the second reporting week.
The NCDC also stated that the National Lassa Fever multi-partner, multi-sectoral Incident Management System has been activated to coordinate response activities at all levels.