Nigeria records decline in Lassa fever cases but fatalities remain high — NCDC

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

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 per cent, which is higher than the 16.4 per cent 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 per cent of all confirmed cases originated from Ondo, Bauchi, Edo, and Taraba states.

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

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.

National and state response activities

The situation report detailed a wide range of response activities implemented during the week.

These include behavioural assessments in high-burden states, ongoing infection prevention and control work, a series of 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.

Persistent challenges

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.

The high cost of treatment, according to the agency, continues to discourage timely care-seeking.

Sustained vigilance

The agency urged state governments to intensify community engagement and sustain prevention campaigns throughout the year.

It also encouraged healthcare workers to maintain a high index of suspicion for Lassa fever and ensure timely referral and treatment of suspected cases.

The NCDC and its partners said they would continue to strengthen state-level capacity to prevent, detect and respond to outbreaks more efficiently.

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.