Last reviewed May 16, 2026

Lassa fever explained for Nigerians

Lassa fever is a viral illness linked to rodents and is an important public-health concern in Nigeria and parts of West Africa.

Quick answer

Lassa fever is caused by Lassa virus. People can become infected through food or household items contaminated by urine or faeces from infected multimammate rats. Person-to-person spread can also happen, especially in healthcare settings without strong infection control.

If you have fever or severe symptoms, do not self-diagnose. Seek medical care quickly.

Possible symptoms

Symptoms may begin gradually with fever, weakness, headache, and malaise. Other symptoms can include sore throat, muscle pain, chest pain, nausea, vomiting, diarrhoea, cough, and abdominal pain. Severe cases may involve bleeding, low blood pressure, shock, or organ complications.

How Lassa fever spreads

The main route is contact with food or household items contaminated by infected rodent urine or faeces. Person-to-person transmission can occur through contact with blood, body fluids, or contaminated materials.

Prevention

  1. Store food in covered containers.
  2. Keep homes and surroundings clean to reduce rodents.
  3. Avoid drying food where rodents can reach it.
  4. Wash hands and avoid contact with blood or body fluids of sick people.
  5. Seek care early if symptoms appear.

Related: Lassa fever vs malaria, Hantavirus vs Lassa fever, Rat urine disease.