The Nigeria Centre for Disease Control and Prevention (NCDC) has reported a slight decrease in new Lassa fever infections in epidemiological week 47, even as fatalities from the disease continue to surpass last year’s figures.

In its latest situation report for 17–23 November 2025, the agency said 17 new confirmed cases were recorded across Ondo, Bauchi, Edo, and Taraba states, a drop from the 19 cases reported the previous week.

Cumulatively, Nigeria has confirmed 1,012 Lassa fever cases and 185 deaths as of week 47.

This represents a case fatality rate of 18.3 percent, which is higher than the 16.4 percent recorded within the same period in 2024.

The report shows that 21 states have recorded at least one confirmed case this year, with infections spread across 102 local government areas.

The burden remains concentrated, as 87 percent of all confirmed cases originated from Ondo, Bauchi, Edo, and Taraba states.

Ondo accounted for the highest proportion with 37 percent, followed by Bauchi with 21 percent, Edo with 17 percent, and Taraba with 12 percent.

The report shows that the disease continues to affect young adults the most. The predominant age group is 21–30 years, with a median age of 30. The male-to-female ratio among confirmed cases is 1:0.8.

The NCDC also reported that no healthcare worker was infected in week 47.

Case numbers remain lower than last year.

The agency noted that both suspected and confirmed cases are fewer than those reported at the same time in 2024.

However, it warned that delays in seeking care remain a major driver of the high fatality rate. Poor health-seeking behaviour, coupled with the high cost of treatment, continues to push many patients to present late at health facilities, reducing their chances of survival.

The situation report detailed a wide range of response activities implemented during the week, including behavioural assessments in high-burden states, ongoing infection prevention and control work, After Action Reviews for the 2024/2025 outbreak season, and continued training of Lassa fever clinical management fellows.

National Rapid Response Teams were also deployed to multiple states to support surveillance and treatment, while essential supplies such as personal protective equipment, ribavirin, body bags, and thermometers were distributed to treatment centres.

The NCDC also highlighted ongoing collaboration with partners on clinical trials, environmental response campaigns, updated risk communication strategies, and digital learning platforms for infection control.

Several states, including Ondo, Edo, Ebonyi, and Lagos, continued state-level interventions ranging from clinician sensitisation to temperature monitoring of contacts.

Despite these efforts, the NCDC acknowledged persistent challenges affecting the national response.

It said late presentation remains one of the most significant barriers to reducing fatalities.

It also noted that conditions in many high-burden communities remain poor, with inadequate sanitation and limited awareness contributing to sustained transmission.