According to the agency’s latest situation report for 17–23 November 2025, 17 new confirmed cases were reported across Ondo, Bauchi, Edo, and Taraba states, down from 19 cases the previous week. Cumulatively, Nigeria has confirmed 1,012 cases of Lassa fever and 185 deaths as of week 47, representing a case fatality rate of 18.3 percent, higher than the 16.4 percent recorded during the same period in 2024.
The report indicates that 21 states have recorded at least one confirmed case this year, spanning 102 local government areas. However, the disease burden remains concentrated in Ondo, Bauchi, Edo, and Taraba, which together account for 87 percent of all confirmed cases. Ondo state alone reported the highest proportion at 37 percent, followed by Bauchi (21 percent), Edo (17 percent), and Taraba (12 percent).
Lassa fever continues to affect young adults disproportionately. The predominant age group among confirmed cases is 21–30 years, with a median age of 30, and a male-to-female ratio of approximately 1:0.8. The report confirmed that no healthcare worker contracted the disease during the week under review.
Case Numbers Lower than Last Year, Fatalities Driven by Late Care
While both suspected and confirmed cases remain lower than those reported at the same time in 2024, the NCDC warned that delays in seeking medical care are a major contributor to the persistently high fatality rate. Poor health-seeking behaviour, compounded by the high cost of treatment, often leads patients to present late at healthcare facilities, reducing their chances of survival.
Ongoing National and State Response Efforts
The situation report highlighted extensive response measures implemented during the week. National Rapid Response Teams were deployed to multiple states to support surveillance and clinical management, while essential supplies—including personal protective equipment, ribavirin, thermometers, and body bags—were distributed to treatment centres.
Other interventions included behavioural assessments in high-burden states, infection prevention and control activities, After Action Reviews for the 2024/2025 outbreak season, and continued training of Lassa fever clinical management fellows. Collaboration with partners also continues on clinical trials, environmental response campaigns, updated risk communication strategies, and digital learning platforms for infection control.
At the state level, Ondo, Edo, Ebonyi, and Lagos continued targeted measures such as clinician sensitisation, contact monitoring, and community engagement campaigns.
Persistent Challenges Hamper Response
Despite these efforts, the NCDC acknowledged ongoing challenges that hinder effective outbreak control. Late presentation to healthcare facilities remains the most significant barrier to reducing fatalities, while poor sanitation, limited awareness, and high treatment costs continue to contribute to sustained transmission in high-burden communities.
Call for Sustained Vigilance
The agency urged state governments to intensify community engagement and maintain prevention campaigns throughout the year. Healthcare workers are also advised to sustain a high index of suspicion for Lassa fever and ensure timely referral and treatment of suspected cases. The NCDC and its partners pledged to continue strengthening state-level capacity to detect, prevent, and respond to outbreaks more efficiently.
Lassa Fever
Lassa fever is an acute viral haemorrhagic illness caused by the Lassa virus, primarily transmitted through contact with food or household items contaminated by the urine or faeces of infected rodents. Person-to-person transmission can also occur through contact with bodily fluids. The disease often begins with fever, weakness, and headache, potentially progressing to severe symptoms such as bleeding, difficulty breathing, swelling, and organ failure. Early diagnosis and prompt treatment with ribavirin are critical to improving survival.