The Nigeria Centre for Disease Control and Prevention (NCDC) has reported 1,119 confirmed cases of Lassa fever in 2025, with young adults emerging as the most affected age group nationwide.
The agency disclosed this in its Lassa Fever Situation Report for Epidemiological Week 51, covering Dec. 15 to 21, 2025, which provided an overview of cases, deaths and affected states across the country.
According to the report, individuals aged 21 to 30 years accounted for the highest number of confirmed infections, while the median age of patients was 30 years.
The NCDC noted that males were slightly more affected than females, suggesting differences in exposure risks or health-seeking behavior in communities with high transmission.
As of the reporting period, 206 deaths had been recorded among confirmed cases, representing a case fatality rate of 18.4 per cent. This is higher than the 16.4 per cent recorded during the same period in 2024.
During Epidemiological Week 51, 21 new confirmed cases and five deaths were reported, a decline from the 28 cases recorded in the previous week, indicating a modest reduction in new infections.
The cases were reported from Bauchi, Ondo, Taraba, Edo, Kogi, Ebonyi and Plateau states. Overall, 21 states across 105 Local Government Areas recorded at least one confirmed case in 2025.
Four states—Ondo, Bauchi, Edo and Taraba—accounted for 88 per cent of all confirmed cases, with Ondo State alone contributing 35 per cent of the national total.
The NCDC identified late presentation at health facilities, poor health-seeking behavior due to high treatment costs, and poor environmental sanitation in high-burden communities as major challenges to outbreak control.
It urged healthcare workers to maintain a high index of suspicion for Lassa fever, ensure early diagnosis and prompt treatment, and called on state governments to strengthen risk communication and community engagement.
The agency said it would continue to coordinate a multi-sectoral national response, including surveillance, case management, laboratory support, and infection prevention and control activities in affected and at-risk areas.
Lassa fever is an acute viral haemorrhagic illness transmitted mainly through contact with food or household items contaminated with the urine or faeces of infected rodents. Human-to-human transmission can also occur, particularly in healthcare settings.
