Symptoms of Lassa fever

Learn about the symptoms of Lassa fever and what to do if you become ill.

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Symptoms of Lassa fever

In about 80% of people infected with the Lassa virus, the illness is mild or there are no noticeable symptoms. However, in 20% of infected individuals the disease can result in severe illness and hospitalization.

Symptoms can begin 7 to 10 days after exposure. They usually last for 16 days, although a range of 6 to 30 days is possible. Symptoms include:

  • fever
  • diarrhea
  • vomiting
  • headache
  • chest pain
  • facial swelling
  • abdominal pain
  • sore throat and cough
  • bleeding from nose or mouth

Permanent hearing loss can be a common result of the virus.

Symptoms of Lassa fever are similar to those of other viral haemorrhagic fevers and infectious diseases like malaria or typhoid. They affect the vascular system, which controls how blood moves through the body.

The virus can result in significant internal bleeding and organ failure.

What to do if you become ill

See your health care provider immediately if you or anyone in your household:

  • is showing some of the listed symptoms
  • has travelled to an area where the Lassa virus is present
  • has come into contact with someone who has Lassa fever

Make sure to tell your health care provider your full travel history.

Describe your symptoms over the phone before your appointment. This is so that health care staff can arrange to see you without exposing themselves or others to your illness.

The sooner you get treatment, the better your chances are for recovery.

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