The Nigeria Centre for Disease Control and Prevention (NCDC) has published the Lassa Fever Situation Report for Week 40, covering the period from 29th September to 5th October 2025.
During the week under review, there was an increase in the number of confirmed Lassa fever cases from four in Epidemiological Week 39 to thirteen in Week 40. All the new cases were reported from Ondo State. Cumulatively, as of Week 40, a total of 924 confirmed cases and 172 deaths have been recorded in 2025, representing a case fatality rate (CFR) of 18.6 percent. This is higher than the 17.0 percent recorded during the same period in 2024.
So far, twenty-one states across one hundred and six Local Government Areas (LGAs) have reported at least one confirmed case of Lassa fever. The majority of confirmed cases, about ninety percent, were reported from Ondo, Bauchi, Edo, Taraba, and Ebonyi States. The most affected age group remains individuals between 21 and 30 years. It is noteworthy that no new healthcare worker infection was recorded during the reporting week.
Although the total number of suspected and confirmed cases has decreased compared to the same period in 2024, the increase in the case fatality rate is of concern. This trend may indicate delays in detection, late presentation at health facilities, or challenges in case management. Continued vigilance, early detection, and prompt treatment remain essential to reducing mortality associated with the disease.
The concentration of cases in a few states highlights the need for sustained surveillance and strengthened response activities, particularly in high-burden areas. Infection prevention and control measures must continue to be enforced in healthcare facilities, while community awareness and sensitization efforts should be intensified to encourage early reporting of symptoms and preventive practices. The absence of new infections among healthcare workers is commendable and reflects ongoing efforts to maintain strict infection prevention standards.
The NCDC, in collaboration with state Ministries of Health and partners, continues to enhance coordination, surveillance, laboratory capacity, case management, and risk communication to curb the spread of the disease. Lassa fever remains endemic in Nigeria, and a sustained, multisectoral approach is essential to reduce its impact across affected communities.
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