Clinical and epidemiological characteristics of confirmed Lassa fever cases between December 2024 and February 2025 in Ebonyi State, Nigeria

Introduction: Lassa Fever (LF) is an acute viral haemorrhagic illness endemic to West African countries. The disease remains a major public health concern in Nigeria and accounts for most reported global cases annually. Despite improvements in surveillance and case management, mortality remains high. Ebonyi State experiences recurrent outbreaks, yet limited case-level data exist to guide early detection and clinical response. Methods: A retrospective case series was conducted of laboratory-confirmed LF cases admitted at the designated LF treatment centre in Ebonyi State between December 2024 and February 2025. Data were extracted from hospital records, the Nigeria Centre for Disease Control and Prevention (NCDC) case investigation forms, and state surveillance line lists. The variables included demographic, clinical, and outcome characteristics. Descriptive statistics were summarised using medians and proportions. Results: Ten laboratory-confirmed cases were identified across multiple LGAs. The median age was 25.5 years (interquartile range: 18.8 – 29.0), and 60% were male. The most common presenting symptoms were fever, headache, and generalised weakness. Five of ten patients (50%) were initially treated for malaria or typhoid before LF was suspected. Severe complications, particularly bleeding and AKI, were observed more frequently among fatal cases. The overall case fatality rate was 40%, with all deaths occurring among patients presenting ≥5 days after symptom onset (median time to presentation: 7.5 days [fatal] versus 7.0 days [recovered]). Conclusion: Delayed presentation, initial misdiagnosis and severe complications were observed more frequently among fatal cases during the 2024–2025 LF transmission season in Ebonyi State. Early clinical suspicion, prompt referral, and timely initiation of Ribavirin and supportive care are likely important for improving survival, consistent with evidence from similar Lassa fever treatment settings in West Africa. Strengthening clinician awareness, diagnostic capacity, and community health-seeking behaviour remains essential to reducing LF-related mortality in endemic regions.