Overview
Lassa fever is a viral haemorrhagic illness spread mainly through food or household items contaminated by infected rodents. It is found in parts of West Africa and is occasionally seen in returning travellers, so it is mainly relevant to people who have recently visited an affected area. Early symptoms resemble other tropical fevers, which is why a fever after travel that does not improve needs urgent review. Early hospital treatment greatly improves survival.
Symptoms
- Fever and general weakness
- Headache
- Sore throat
- Muscle and chest pain
- Nausea, vomiting or diarrhoea
- Bleeding from gums, nose or other sites (late, severe sign)
- Hearing problems during recovery
Causes & risk factors
- Contact with food or surfaces contaminated by rat urine or droppings
- Eating rats or poorly stored grains
- Contact with body fluids of an infected person
- Poor food storage that attracts rodents
Treatment & self-care
Suspected Lassa fever needs immediate referral to a hospital or designated treatment centre, where antiviral treatment and supportive care are given under isolation — seek emergency care rather than self-medicating at home. Tell the clinical team about any recent travel so the right precautions are taken. In affected areas, storing food in covered containers and keeping homes rodent-free reduces risk.
See a doctor urgently if
- Fever after recent travel to a West African area where Lassa fever occurs
- Fever with sore throat, vomiting and severe weakness
- Any unusual bleeding from gums, nose, eyes or in urine or stool — seek emergency care
- Fever after contact with a sick person from an outbreak area
This condition can be an emergency. If any of the signs above are severe or getting worse, go to the nearest emergency room now or call your local emergency number — do not wait for an online consultation.