Primary amoebic meningoencephalitis (PAM)
Primary amoebic meningoencephalitis (PAM) is a medical emergency. If you are worried that you or someone you care for may have PAM, go to your nearest emergency department or call triple zero (000) and ask for an ambulance.
Key facts
- Primary amoebic meningoencephalitis (PAM) is a rare but life-threatening illness caused by the amoeba naegleria fowleri.
- Naegleria fowleri lives in warm water, freshwater areas and damp soil.
- It causes illness by going up your nose to your brain.
- Symptoms include headache, high fever, vomiting and neck stiffness.
- You cannot get it from drinking affected water or being in contact with another person.
- To help prevent PAM, swim or play in safe, clean water and stay out of dirty waterholes or dams.
What is primary amoebic meningoencephalitis (PAM)?
Primary amoebic meningoencephalitis (PAM) is a very rare but serious and life-threatening illness. It causes inflammation of the brain. PAM is also known as amoebic meningitis.
PAM is caused by an amoeba called naegleria fowleri, a tiny organism that lives in:
- warm water areas
- freshwater areas
- damp soil
Infection may occur during water activities if water containing the amoeba goes up your nose. Once in the nose, it can travel to your brain.
Children and young adults are more likely to get it, but it can happen at any age.
What are the symptoms of PAM?
The symptoms of PAM are similar to those of meningitis. Symptoms usually start about 5 days after infection, but may appear anywhere from 2 to 15 days after becoming infected.
Symptoms include:
Later symptoms include:
- neck stiffness
- confusion and hallucinations
- loss of balance
- seizures
- drowsiness
- coma
Early diagnosis and treatment may help improve survival, but PAM is fatal in most cases.
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When should I see my doctor or call an ambulance?
Call an ambulance or go straight to the emergency department if you or a child is with symptoms of PAM.
The symptoms of PAM are common for many conditions. Early diagnosis and treatment is important to increase your chances of survival.
If you have symptoms, make sure you tell your doctor about any recent water-based activities.
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What causes PAM?
PAM is caused by an amoeba known as naegleria fowleri that can grow in untreated water. It grows best in warm water at temperatures between 25°C and 40°C.
You can find the amoeba in:
- still water, such as lakes and rivers
- hot bore water
- long surface pipes
- water hoses
- poorly maintained swimming pools, wading pools or spas
PAM infection can occur if water with naegleria fowleri goes up your nose. This may happen when you jump, dive, fall or play in water. It's important to remember that even if affected water goes up your nose, the chance of developing PAM is still very small.
Once in the nose, the amoebas may travel to your brain. In the brain, they destroy brain tissue and cause inflammation.
You can't get PAM from:
- drinking water containing with the amoebas
- contact with another person who is affected with PAM
How is PAM diagnosed?
PAM is diagnosed by your doctor checking the fluid surrounding your brain and spinal cord with a lumbar puncture.
The amoebas can be seen under a microscope.
How is PAM treated?
There are no standard treatments for PAM. The most promising approach is combination therapy with several medicines that treat parasites.
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What are the complications of PAM?
PAM is a very rare disease that is usually fatal. When not fatal, serious brain damage is the most common complication.
Can PAM be prevented?
Because PAM is dangerous and usually fatal, even with treatment, prevention is important.
Help prevent PAM at home:
- Don't let water to go up your nose when showering or washing your face.
- Before using a hose or sprinkler, let the water run until it is cool.
- Supervise children playing with hoses or sprinklers.
- Teach children not to squirt water up their noses.
- Disinfect swimming pool water with chlorine, as it kills all stages of the amoeba.
- Keep wading pools clean by emptying and scrubbing — let them dry in the sun after use.
- Only swim in or play with safe and disinfected water.
To help prevent PAM when you are out:
- Stay out of dirty waterholes or dams.
- Never jump or dive into water — instead, walk or lower yourself in.
- Swim in seawater or properly chlorinated pools rather than fresh water.
- Keep your head above water in spas, thermal pools and warm fresh water.
- Do not dig or stir up sediment in the water.
On remote properties, filtering and disinfecting the water used for washing and playing can help prevent PAM.
Resources and support
You can learn more about PAM through these state and territory health departments:
You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available 24 hours a day, 7 days a week.
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Last reviewed: July 2024
