Lassa fever has claimed 206 lives across Nigeria in 2025, with five deaths recorded in a single week, pushing the case fatality rate (CFR) to an alarming 23.8 per cent for the week and 18.4 per cent cumulatively for the year, the Nigeria Centre for Disease Control and Prevention (NCDC) has disclosed.
The figures represent a significant increase from the 16.4 per cent CFR recorded at the same period in 2024, raising concerns among public health authorities despite a decline in the number of new infections.
According to the NCDC’s Situation Report for Epidemiological Week 51 (15–21 December), 21 new confirmed cases were recorded nationwide, a drop from 28 cases reported the previous week. However, the agency warned that the sustained high death toll continues to overshadow the reduction in cases.
The report showed that fresh cases during the week were recorded in Bauchi, Ondo, Taraba, Edo, Kogi, Ebonyi and Plateau states, while 21 states and 105 local government areas have now been affected by the outbreak in 2025.
Data from the agency revealed that 88 per cent of all confirmed cases were concentrated in just four states: Ondo (35 per cent), Bauchi (25 per cent), Edo (16 per cent) and Taraba (12 per cent), underscoring persistent transmission in known hotspots.
Young adults remain the most vulnerable group, with those aged 21 to 30 years accounting for the highest number of confirmed cases. Overall, infections were recorded among Nigerians aged between one and 96 years, with a median age of 30 years. Males were slightly more affected than females.
The NCDC attributed the rising fatality rate largely to late presentation of cases, poor health-seeking behaviour and the high cost of treatment in high-burden communities, noting that many patients arrive at health facilities when the disease has already progressed to severe stages. “Late presentation continues to drive up mortality. Early detection and prompt treatment remain critical to survival,” the agency stated.
On a positive note, the report confirmed that no healthcare worker was infected during the week under review, reflecting improvements in infection prevention and control (IPC) practices across treatment centres. During the period, 16 patients were managed in designated facilities, while 77 contacts remained under follow-up nationwide.
The NCDC also highlighted several response efforts undertaken in 2025, including the deployment of 10 National Rapid Response Teams, expansion of IPC training, behavioural risk assessments in hotspot states, environmental sanitation campaigns, vaccine development planning and cross-border collaboration within ECOWAS.
Despite recording fewer suspected and confirmed cases compared with 2024, the agency warned against complacency as Nigeria enters the peak Lassa fever season, urging state governments to intensify community engagement, early case reporting and sanitation efforts.
The NCDC reaffirmed its commitment to working with state governments and development partners to strengthen capacity for early detection, rapid response and effective case management, warning that without improved care-seeking behaviour and environmental hygiene, the virus will continue to claim avoidable lives.
