What Is Lassa Fever?
Lassa fever is caused by the Lassa virus, an arenavirus transmitted primarily through contact with infected rodents, especially the multimammate rat (Mastomys natalensis).
Most infections occur through:
- Contaminated food
- Exposure to rodent urine or droppings
- Inhaling contaminated dust
How It Spreads (Person to Person)
Human-to-human transmission happens through:
- Direct contact with blood or bodily fluids of a symptomatic person
- Caregiving without protective barriers
- Contaminated medical equipment
- Sexual contact (virus can persist in semen for up to 3 months)
Early Signs
Incubation period: 2–21 days
Early symptoms often resemble flu:
- Fever (≥37.5°C)
- Weakness and fatigue
- Headache
- Sore throat
- Muscle pain
- Nausea or vomiting
About 80% of infections are mild or asymptomatic.
Severe Warning Signs
In roughly 20% of cases:
- Chest pain
- Facial swelling
- Diarrhoea
- Bleeding (gums, mouth)
- Low blood pressure
- Respiratory distress
- Hearing loss
Severe cases require urgent hospital care.
2026 Outbreak Snapshot (Mid-February)
- 165 confirmed cases
- 754+ suspected cases
- 31 deaths
- Case Fatality Rate (CFR): ~18–20%
Most affected states:
- Bauchi – 43 cases, 8 deaths
- Ondo – 19 cases, 1 death
15 health workers have been infected, highlighting occupational risk in endemic areas.
2025 Outbreak in Context
Full year 2025:
- 955–995 confirmed cases
- 176–184 deaths
- 18.4–18.5% CFR
- 21 states affected
Over 88% of cases were concentrated in:
- Ondo
- Bauchi
- Edo
- Taraba
Higher fatality rates were linked to delayed treatment and poor sanitation.
Treatment & Why Early Action Matters
There is no widely available vaccine.
Early supportive care significantly improves survival:
- Immediate hydration
- Symptom management
- Strict isolation protocols
Ribavirin antiviral is often used early (especially intravenously), with better outcomes when administered within the first few days of illness.
Prevention
Reduce rodent exposure:
- Store food in sealed containers
- Keep homes clean and rodent-proof
- Dispose of waste properly
Healthcare settings must:
- Enforce infection control
- Use gloves, masks, and proper sterilization
Government & Public Health Response
Nigeria’s Nigeria Centre for Disease Control (NCDC) is leading the response.
- National Lassa Fever Emergency Operations Centre (LF-EOC) activated at Response Level 2
- Rapid Response Teams (RRTs) deployed to affected states
- Distribution of PPE and essential medications
- Infection Prevention & Control (IPC) training intensified
- 15 health worker infections recorded
Operational Actions:
- High-level field missions (including Bauchi)
- Laboratory testing and surveillance
- Contact tracing for 110+ suspected cases
- 135 confirmed cases managed in treatment centers
- Isolation units are activated in health facilities
- State-level advisories issued
- Budget advocacy for prevention funding
