Most of our people still do not recognize that Lassa Fever in Nigeria continues to pose a serious public health threat, with the Nigeria Centre for Disease Control (NCDC) reporting confirmed cases and deaths in states like Ondo, Edo, Bauchi, and Taraba during the 2025–2026 season. This viral hemorrhagic fever, primarily transmitted through contact with infected multimammate rats, has seen outbreaks peak annually from December to April, affecting thousands and claiming hundreds of lives each year. Understanding Lassa Fever in Nigeria, its symptoms, causes, and proven prevention strategies, is essential for communities, healthcare workers, and travelers to reduce transmission and improve survival rates.pmc.ncbi.nlm.nih+3
What is Lassa Fever?
Definition and virus biology
Lassa fever is an acute viral illness caused by the Lassa virus, a member of the Arenaviridae family, first identified in 1969 in Lassa town, Nigeria. The virus naturally infects multimammate rats (Mastomys natalensis), which serve as the primary reservoir and shed the virus in their urine, droppings, and saliva without becoming ill. Humans become infected through direct contact with these rodent excreta, contaminated food, or surfaces, with an incubation period of 6 to 21 days.who+2
About 80% of infections are mild or asymptomatic, but the remaining 20% can progress to severe disease, particularly in vulnerable groups. Unlike Ebola, Lassa fever is not airborne but spreads via mucous membranes, cuts, or ingestion, making hygiene and rodent control central to prevention.who+2
Lassa fever burden in Nigeria
Nigeria accounts for the majority of global Lassa fever cases, with the disease now endemic in over 34 states, up from about 20 a decade ago. Annual outbreaks typically report 500–1,000 confirmed cases, but under reporting means the true burden is likely much higher, with case fatality rates (CFR) ranging from 1% overall to 15–20% among hospitalized patients. In the first quarter of 2025 alone, NCDC recorded cases with 118 deaths, prompting heightened surveillance.cidrap.umn+5
The economic toll is significant, including healthcare costs, lost productivity, and disruptions in endemic areas like the Middle Belt and Southeast. Healthcare workers face elevated risks due to nosocomial transmission, with multiple infections reported yearly.frontiersin+3
Current Lassa Fever Outbreak in Nigeria
Nigeria’s 2025–2026 Lassa season follows patterns of resurgence, with Ondo State reporting 107 confirmed cases and 10 deaths by late 2025, alongside clusters in Edo, Bauchi, Gombe, Kogi, and Ebonyi (Lassa fever outbreak 2026 Nigeria states). Epi Week 45 (Nov 2025) situation reports note ongoing transmission, with NCDC activating emergency operations centres (NCDC Lassa fever response Nigeria).fmino+4
Response includes expanded treatment centres (15+ nationwide), contact tracing (thousands traced), and cross‑border alerts, amid challenges like low testing rates and HCW infections.fmino+1
Symptoms of Lassa Fever
Recognizing Lassa fever symptoms early is crucial, as timely medical intervention can dramatically lower fatality rates from over 50% in untreated severe cases to around 15% with supportive care. Symptoms often start mildly, mimicking malaria or typhoid, which delays diagnosis in Nigeria’s resource‑limited settings.pmc.ncbi.nlm.nih+3
- Fever, weakness, and malaise: Persistent high fever (above 38°C), extreme fatigue, and general unwell feeling mark the onset, lasting 3–5 days (Lassa fever symptoms in Nigeria).cdc+1
- Headache, sore throat, and muscle pain: Severe frontal headache, painful throat with white patches (exudative pharyngitis), and body aches, especially in the chest and back (Lassa fever early symptoms Nigeria).who
- Nausea, vomiting, diarrhoea, cough, and abdominal pain: Gastrointestinal upset, dry cough, and stomach cramps develop next, sometimes with constipation (severe Lassa fever signs in Nigerians).who
- Facial swelling, fluid in lungs, bleeding, low blood pressure, and shock: In severe cases (10–15%), swelling around eyes/face, respiratory distress, mucosal bleeding, hypotension, and organ failure signal high risk (Lassa fever complications Nigeria).who+1
- High‑risk groups: Pregnant women face 30% fetal loss and higher maternal mortality; young children under 2 and malnourished individuals suffer worse outcomes (Lassa fever risks pregnant women Nigeria).who
Causes and Transmission
Primary causes and risk factors
The root cause of Lassa fever is exposure to the Lassa virus carried asymptomatically by multimammate rats, which thrive in Nigeria’s agricultural areas, homes, and farmlands. Risk factors include poor housing with gaps allowing rodent entry, improper food storage, and inadequate sanitation—common in rural and peri‑urban communities (Lassa fever causes in Nigeria homes).pmc.ncbi.nlm.nih+3
Malnutrition, immunosuppression (e.g., HIV), and delayed healthcare access exacerbate severity, while seasonal farming increases rodent contact (Lassa fever transmission Nigeria rural areas).pmc.ncbi.nlm.nih+1
How Lassa fever spreads
- Zoonotic transmission: Primary route via inhaling aerosolized rat urine/droppings when sweeping, eating contaminated grains/nuts, or touching surfaces then mouth/eyes (Lassa fever rat prevention Nigeria).who
- Human‑to‑human spread: Secondary via direct contact with blood, vomit, feces, or urine of infected persons, mainly in healthcare settings without gloves/masks (hospital transmission Lassa fever Nigeria).afenet-journal+1
- No airborne or casual contact: Unlike flu, it requires close fluid exposure; low international risk but monitor air travel from endemic zones (Lassa fever travel risk from Nigeria).cdc+1
Diagnosis and Treatment of Lassa Fever in Nigeria
Diagnostic methods
Diagnosis combines clinical suspicion (fever + exposure history in endemic areas) with lab tests like reverse transcription polymerase chain reaction (RT‑PCR) for viral RNA or enzyme‑linked immunosorbent assay (ELISA) for IgM antibodies, available at NCDC reference labs and treatment centres (Lassa fever diagnosis Nigeria).ncdc+1
Challenges include nonspecific early symptoms, rural lab access gaps, and overburdened systems during peaks (Lassa fever testing challenges Nigeria). Rapid antigen tests are under evaluation, but PCR remains gold standard.pmc.ncbi.nlm.nih+2
Treatment options
No specific antiviral cure exists, but ribavirin (IV, started within 6 days) reduces mortality in severe cases, per WHO/NCDC guidelines, alongside aggressive supportive care: IV fluids, pain management, oxygen, and bleeding control (Lassa fever treatment ribavirin Nigeria).ncdc+2
Isolation in designated centres with PPE prevents spread; CFR falls to <10% with early admission (Lassa fever survival rate Nigeria). Experimental therapies like monoclonal antibodies show promise in trials.who+2
Lassa Fever Prevention in Nigeria
Rodent control and home hygiene
Effective prevention targets rodents and hygiene, as no licensed vaccine exists yet (phase 2 trials ongoing).
- Store food securely: Use metal/rodent‑proof containers for grains, nuts; dispose waste daily in covered bins (prevent Lassa fever home Nigeria).ncdc+2
- Block entry points: Seal cracks, doors, windows; keep compounds clean, avoid clutter (Lassa fever prevention tips Nigeria).pmc.ncbi.nlm.nih+1
- Safe cleaning: Wet mop floors, wear nose masks/gloves when cleaning rodent areas; cook food thoroughly (Lassa fever rodent control Nigeria).pmc.ncbi.nlm.nih+1
Community and healthcare measures
- Personal hygiene: Frequent handwashing with soap, avoid touching face; safe burial for deceased (Lassa fever community prevention Nigeria).afenet-journal+1
- Healthcare protocols: HCWs use full PPE, single‑use needles, patient isolation; report suspects to NCDC hotline 0800-9700-2010 (NCDC Lassa fever guidelines).who+1
- Public education: Community sensitization on risks, early reporting; rodent trapping campaigns (Lassa fever vaccine update Nigeria).afenet-journal+1
Expert Opinions and Quotes
Experts stress integrated prevention amid rising cases.
- WHO (2023): “From 1 January to 6 March 2023, Nigeria reported 127 confirmed cases… including 32 deaths (case-fatality ratio: 25%)… robust response ongoing.” Calls for vigilance. who
- Frontiers Public Health (2025): “Fatality rate… 13.5–18.3% underscores limitations in early detection… paradigm shift toward preventive strategies essential for Nigeria.” Frontiers Public Health
- PMC Economic Impact Study (2025): “The resurgence… imposes substantial economic burden… controlling Lassa fever requires political will, sustained financing, multisectoral strategy.”
- WHO Fact Sheet (2024): “Early diagnosis and supportive care improve outcomes… no licensed vaccine, but candidates in trials; rodent control primary prevention.” Global view.
- Afenet Journal (2023): Local study found “multi‑sectoral approach effective for prevention… but gaps in knowledge translation persist.”
Frequently Asked Questions
What is Lassa fever?
Lassa fever is a viral hemorrhagic illness caused by Lassa virus from infected rats, endemic in Nigeria (Lassa fever definition Nigeria).who
What are Lassa fever symptoms in Nigeria?
Starts with fever, headache, sore throat; progresses to vomiting, swelling, bleeding in severe cases (early Lassa fever symptoms).cdc+1
How does Lassa fever spread in Nigeria?
Via rat urine/food contamination or human fluids in hospitals (Lassa fever transmission modes).who
Is Lassa fever deadly?
Yes, 1–2% overall CFR, up to 20% hospitalized; worse for pregnant women (Lassa fever fatality rate Nigeria).pmc.ncbi.nlm.nih+1
How to prevent Lassa fever in Nigeria?
Rodent‑proof homes, safe food storage, hygiene, early reporting (Lassa fever prevention home).ncdc+1
Lassa fever treatment in Nigeria?
Supportive care + ribavirin; isolation at centres (ribavirin Lassa fever Nigeria).ncdc+1
Final Thoughts
Our hope is that with adequate knowledge on the causes, symptoms, prevention and treatment of Lassa Fever in Nigeria, individuals and communities will be empowered with the right knowledge needed to act amid ongoing outbreaks. By prioritizing rodent control, hygiene, and rapid reporting to NCDC, Nigerians can curb transmission and save lives, stay vigilant this season.ncdc+3
Medical Disclaimer: This post provides general information only and is not medical advice. Consult a healthcare professional for symptoms or concerns. Sources cited for accuracy.who
Related Reading
RELATED POSTS
View all
