Lassa fever is a viral hemorrhagic fever caused by the Lassa virus, transmitted to humans through contact with infected rodents or contaminated food and water. It’s prevalent in West Africa, particularly in Nigeria.

Lassa fever is a significant public health concern in Nigeria, with outbreaks occurring annually, particularly during the dry season from November to May. The Nigeria Centre for Disease Control and Prevention (NCDC) has reported 318 confirmed cases and 70 deaths across the country between December 29, 2025, and February 15, 2026, with a case fatality rate of 22%.

The outbreak is concentrated in five states: Bauchi, Ondo, Taraba, Edo, and Plateau, which account for 91% of confirmed cases. The NCDC has activated its Incident Management System and deployed Rapid Response Teams to eight affected states to enhance surveillance, case management, and community sensitization. Laboratory testing commodities, treatment medicines, personal protective equipment (PPE), and infection prevention materials have been distributed nationwide.

The disease is transmitted to humans primarily through contact with food or household items contaminated by the urine or feces of infected rodents, and secondary transmission can occur person-to-person, especially in healthcare settings. Symptoms include fever, headache, sore throat, muscle pain, vomiting, and diarrhea, with severe cases leading to bleeding, respiratory distress, and organ failure.

The NCDC has urged state governments to intensify active case search and contact tracing, scale up community risk communication, address treatment cost barriers, and enforce infection prevention and control measures. Healthcare workers are advised to maintain a high index of suspicion and ensure timely referral and treatment of suspected cases.