Lassa fever and other arenavirus infections

Arenaviruses are a type of small virus commonly found in rodents. When a person becomes infected with an arenavirus, symptoms usually begin within 10 days. Arenaviruses can cause two main types of disease: neurological disease (caused by Lymphocytic choriomeningitis (LCM) virus) and haemorrhagic fevers caused by Lassa virus, and other viruses such as Machupo and Junín viruses. However, it is possible to have an arenavirus infection without symptoms.

Neurological symptoms

Neurological symptoms include serious conditions such as aseptic meningitis, encephalitis, or meningoencephalitis.

Haemorrhagic fever symptoms

Haemorrhagic fever can begin with symptoms including:

• fever

• headache

• dizziness

• weakness

• sore throat

• cough

• chest

• abdominal pain

• vomiting.

In severe cases, there may be swelling around the face and eyes, bleeding from the nose, gums and other areas along with seizures and coma, which can be fatal.

Key Facts

How it spreads

Arenaviruses are commonly found in rodents, and can spread to people if they come into contact with the faeces or urine of infected rodents or if they inhale dust that contains the virus. These viruses can lead to serious illnesses in people, and there is a possibility of the virus spreading from person to person through bodily fluids or droplets.

Vaccination and treatment

There is no vaccine available for Lassa fever, but the use of a medication called Ribavirin is effective in treatment. It works best when given within the first 6 days of the illness but it is not safe to use during pregnancy.