The Federal Government says Nigeria recorded 1,148 confirmed cases and 215 deaths from Lassa fever across 22 states between epidemiological week one and week 52 of 2025.
This is contained in the latest Lassa Fever Situation Report released by the Nigeria Centre for Disease Control and Prevention (NCDC).
According to the report, the number of confirmed cases declined compared with the 1,309 cases recorded during the same period in 2024.
However, fatalities increased, with the case fatality rate (CFR) rising to 18.7 per cent in 2025, higher than the 16.3 per cent recorded in 2024.
The NCDC noted that cumulatively, 215 deaths were recorded in 2025, compared with 214 deaths during the same period in 2024.
The report also showed that the total number of suspected cases in 2025 stood at 9,389, a decrease from 10,098 recorded in 2024.
It stated that new confirmed cases increased from 21 in epidemiological week 51 to 27 in week 52, with infections reported from Bauchi, Ondo, Ebonyi, Taraba and Nasarawa states.
The agency added that no healthcare worker was affected during the reporting week.
According to the NCDC, a total of 22 states recorded at least one confirmed Lassa fever case across 107 local government areas in 2025.
It said that 89 per cent of all confirmed cases were reported from Ondo, Bauchi, Taraba and Edo states.
The report further revealed that the most affected age group remained those aged 21 to 30 years, with cases ranging from one to 96 years and a median age of 30 years.
It added that the male-to-female ratio among confirmed cases was 1:0.8, indicating a slightly higher infection rate among males.
The NCDC identified late presentation of cases, poor health-seeking behaviour due to high treatment costs, poor environmental sanitation and low awareness in high-burden communities as major factors contributing to the high fatality rate.
The agency urged state governments to intensify year-round community engagement on Lassa fever prevention.
It also called on healthcare workers to maintain a high index of suspicion for the disease and ensure timely referral and treatment of suspected cases.
The NCDC emphasised the need for stronger state-level capacity to prevent, detect and respond promptly to Lassa fever outbreaks across the country.