The Nigerian government has said the country recorded 1,148 confirmed cases and 215 deaths of Lassa fever across 22 states from epidemiological week one to week 52 of 2025.
This was revealed in the latest Lassa Fever Situation Report released by the Nigeria Centre for Disease Control and Prevention (NCDC).
The report shows a decline in the number of confirmed cases recorded in 2025 when compared with 1,309 cases reported 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.
Cumulatively, from week one to week 52 of 2025, the report noted that 215 deaths were recorded, with a CFR of 18.7 per cent, compared with 214 deaths and a CFR of 16.3 per cent during the same period in 2024.
The report also noted that the total number of suspected cases recorded in 2025 stood at 9,389, a decrease from 10,098 in 2024.
According to the report, the number of new confirmed cases in epidemiological week 52 increased from 21 in the previous week to 27.
The infections were reported from Bauchi, Ondo, Ebonyi, Taraba and Nasarawa states.
It added that no healthcare worker was affected during the reporting week.
More details
In total, NCDC noted that 22 states recorded at least one confirmed case across 107 local government areas in 2025.
Of all confirmed Lassa fever cases, 89 per cent were reported from Ondo, Bauchi, Taraba and Edo State.
The NCDC said the most affected age group remains those aged 21–30 years, with cases ranging from one to 96 years and a median age of 30 years.
The male-to-female ratio among confirmed cases was 1:0.8, suggesting slightly higher infection rates among males.
Challenges and recommendations
The NCDC identified late presentation of cases, poor health-seeking behaviour driven by high treatment costs, poor environmental sanitation, and low awareness in high-burden communities as key factors contributing to the high fatality rate.
It urged state governments to intensify year-round community engagement on Lassa fever prevention, called on healthcare workers to maintain a high index of suspicion and initiate timely referral and treatment, and emphasised the need for stronger state capacity to prevent, detect and respond promptly to outbreaks.
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Lassa fever
Lassa fever is an acute viral haemorrhagic illness caused by the Lassa virus, which is transmitted to humans primarily through contact with food or household items contaminated by the urine or faeces of infected rats.
It can also spread from person to person through contact with bodily fluids.
The disease often begins with fever, weakness, and headache, and may progress to more severe symptoms such as bleeding, difficulty breathing, swelling, and organ failure.
Early diagnosis and prompt treatment with Ribavirin are critical for improving survival.
