The Nigeria Centre for Disease Control and Prevention (NCDC) says 166 people died from Lassa fever between January and September 2025, with the case fatality rate now higher than 2024 year.
This is contained in Epidemiological Week 37, covering Sept. 8 to 14, cited on the NCDC website on Thursday.
The Public Health agency said that 895 confirmed cases were recorded across 21 states and 106 local government areas.
It said that this represents a case fatality rate (CFR) of 18.5 per cent, compared to 16.9 per cent reported within the same period in 2024.
The agency noted that while suspected and confirmed cases were fewer than those reported last year, more patients are dying because of late presentation and poor health-seeking behaviour, often linked to the high cost of treatment.
According to NCDC, Ondo, Bauchi, Edo, Taraba and Ebonyi states continue to account for 90 per cent of all confirmed cases, with Ondo alone responsible for a third of infections.
The NCDC also confirmed that no new healthcare worker was infected during the reporting week.
However, it warned that poor environmental sanitation, weak awareness in high-burden communities and delayed treatment continue to fuel the spread and severity of the disease.
It was, reported that Lassa fever is an acute viral haemorrhagic illness caused by the Lassa virus.
It is transmitted to humans through contact with food or household items contaminated by infected rodents, particularly the multi-mammate rat.
Human-to-human transmission can also occur, especially in healthcare settings without adequate infection control.
Symptoms include fever, headache, sore throat, chest pain, vomiting, diarrhoea and in severe cases, unexplained bleeding.
The disease is endemic in parts of West Africa, with Nigeria bearing the highest burden.
To strengthen control, the NCDC said it had deployed 10 rapid response teams to affected states, launched new infection prevention and control (IPC) training modules and supported clinical management fellowship programmes in collaboration with local and international partners.
The agency urged states to intensify community engagement and preventive campaigns and reminded healthcare workers to maintain high suspicion and initiate early treatment when symptoms appear.
