The Nigeria Centre for Disease Control and Prevention (NCDC) has confirmed a rise in Lassa fever cases, with 162 deaths reported across 21 states as of epidemiological week 35, covering August 25 to 31.
The agency reported 10 new confirmed cases in week 35, an increase from three in the previous week, with infections detected in Edo, Ondo, Bauchi, and Taraba states.
Cumulatively, Nigeria has recorded 7,375 suspected cases and 871 confirmed infections in 2025, with a Case Fatality Rate (CFR) of 11.7 percent, higher than the 8.9 percent recorded during the same period in 2024. Ondo, Bauchi, Edo, Taraba, and Ebonyi states remain the country’s hotspots, accounting for 91 percent of all confirmed cases. The breakdown shows Ondo with 33 percent, Bauchi 23 percent, Edo 18 percent, Taraba 14 percent, and Ebonyi 3 percent.
The NCDC noted that most patients are between 21 and 30 years of age, with a male-to-female ratio of 1:0.8. While the overall number of suspected and confirmed cases is lower compared to the same period in 2024, the agency warned of ongoing risks. It identified late presentation of cases, poor health-seeking behaviour linked to treatment costs, and poor sanitation in high-burden communities as major factors contributing to the high death toll.
Although no new healthcare worker infections were reported in week 35, a total of 23 health workers have been affected since the beginning of the year. To curb the spread, the NCDC said it has deployed 10 rapid response teams to support affected states, strengthened surveillance, and distributed medical countermeasures including ribavirin, personal protective equipment, and sanitisers. It also announced plans to launch a five-year strategic plan (2025–2029) for Lassa fever control.
The agency urged Nigerians, especially in hotspot states, to maintain proper hygiene, control rodents, and seek early medical attention to reduce the impact of the disease. Lassa fever, a viral haemorrhagic illness endemic in Nigeria, spreads primarily through contact with food or household items contaminated by infected rats and can also spread between people, particularly in hospitals without strict infection control. Symptoms include fever, weakness, vomiting, and bleeding, with severe cases leading to organ failure.
Nigeria bears the highest global burden of the disease, with most cases originating from Ondo, Edo, Bauchi, Taraba, and Ebonyi states. The illness peaks in the dry season between December and April and has a high fatality rate when patients present late. Treatment with ribavirin is most effective when started early, alongside supportive care. Lassa fever remains one of the country’s deadliest recurrent outbreaks, driven by rodent exposure, poor sanitation, and delays in seeking medical care.
