Health conditions

Amoebic meningitis

What is amoebic meningitis?

Amoebic meningitis is a disease that causes inflammation and eventual destruction of the brain and brain linings. It is rare but usually fatal.

It is caused by a single-celled amoeba that lives in fresh water and damp soil. The amoeba, Naegleria fowleri, can survive in soil for a long time and still reactivate when put in fresh water.

Terms explained

Amoeba – a tiny single-celled organism.

Amoebic meningitis is also known as primary amoebic meningoencephalitis (or PAM).

How do you get amoebic meningitis?

Amoebic meningitis occurs only if water containing active amoebae goes up the nose. The amoebae can then make their way up the nerves to the brain. Children are usually the most susceptible.

You cannot catch it from another person or by drinking contaminated water.

Where do you get it?

Naegleria fowleri is a naturally occurring organism, so any natural fresh water body or poorly treated water could contain it.

The amoebae are most active in water temperatures between 28° and 40°C. You can get amoebic meningitis from:

  • unchlorinated or incorrectly chlorinated fresh water, including tap drinking water or bore water
  • warm inland waters such as dams, lakes, geothermal water or waterholes
  • poorly maintained swimming pools and spas
  • water piped above ground for long distances without proper treatment
  • garden hoses and sprinklers containing stagnant water
  • nasal irrigation with contaminated water.

The amoebae will not grow in salty water, such as sea water and river estuaries. Correct use of chlorine in swimming pools and spas will also stop the amoebae growing.

See tips for healthy swimming for more information.

Signs and symptoms

The following symptoms usually occur within 5 days (between 1 to 7 days) of infection:

  • severe and persistent headache
  • sore throat
  • nausea
  • vomiting
  • high fever
  • sleepiness.

Most victims are children who don’t know the dangers of swimming in or playing with unclean water.

How do I know if someone has amoebic meningitis?

Diagnosis must be made by a medical professional. See a doctor or attend a hospital emergency room urgently if you suspect anyone has contracted amoebic meningitis.

Treatment of amoebic meningitis

Amoebic meningitis is usually untreatable, and results in death.

How can amoebic meningitis be prevented

Be careful when swimming, diving, water-skiing or jet-skiing in fresh or natural water bodies that feel warm to the body.

  • Don’t allow water to go up your nose or a child's nose and do not sniff water into your nose when bathing, showering or washing your face.
  • Don’t allow children to play unsupervised with hoses or sprinklers as they may accidentally squirt water up their nose.
  • Let bath and shower taps run for a few minutes to flush out the pipes.
  • Don’t jump or dive into water – walk or lower yourself in.
  • Swim in and play with safe water only. Stay out of dirty pools, waterholes, dams, swimming pools or spas.
  • Disinfect your swimming pool water. Chlorine is the most effective way to continually disinfect water as it kills all stages of the amoeba.
  • Keep wading pools clean by emptying, scrubbing and allowing them to dry in the sun after each use.
  • Swim in sea water or chlorinated pools rather than fresh water.
  • Do not dig or stir up sediment.
  • Don’t use tap water for nasal irrigation unless it has been further treated.

More information          

  • Water Unit, Environmental Health Directorate
    Department of Health
    Telephone: 9388 4999
    Email: ehinfo@health.wa.gov.au

    Where to get help

    Remember

    • Amoebic meningitis is usually fatal – prevention is vital.
    • Attend a hospital emergency room urgently if you suspect anyone has contracted amoebic meningitis.
    • Don’t allow water to go up your nose or a child's nose.
    • Do not play with garden hoses and sprinklers, or any other sources of unclean water.
    • Keep wading pools clean and only use the water once.
    • Keep your swimming pool or spa clean.
    • Test your swimming pool or spa at least once a day.
    • If you do come in contact with unsafe water, walk or lower yourself in.

    Acknowledgements
    Public Health

    This publication is provided for education and information purposes only. It is not a substitute for professional medical care. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your healthcare professional. Readers should note that over time currency and completeness of the information may change. All users should seek advice from a qualified healthcare professional for a diagnosis and answers to their medical questions.

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