Naegleria infection

Naegleria (nay-GLEER-e-uh) infection is a rare and usually fatal brain infection caused by an amoeba commonly found in freshwater lakes, rivers and hot springs. Exposure occurs during swimming or other water sports.

The amoeba — called Naegleria fowleri — travels up the nose to the brain, where it causes severe damage. Most people who have naegleria infection die within a week.

Millions of people are exposed to the amoeba that causes naegleria infection each year, but only a handful of them ever get sick from it. Health officials don't know why some people develop naegleria infection while others don't.

Avoiding warm bodies of fresh water and wearing nose clips while in the water may help prevent such infections.

Symptoms Causes Risk factors Prevention

Naegleria infection causes a disease called primary amebic meningoencephalitis (muh-ning-go-un-sef-uh-LIE-tis). This disease causes brain inflammation and destruction of brain tissue.

Generally beginning within two to 15 days of exposure to the amoeba, signs and symptoms of naegleria infection may include:

  • A change in the sense of smell or taste
  • Fever
  • Sudden headache
  • Stiff neck
  • Sensitivity to light
  • Nausea and vomiting
  • Confusion
  • Loss of balance
  • Sleepiness
  • Seizures
  • Hallucinations

These signs and symptoms can progress rapidly. They typically lead to death within a week.

When to see a doctor

Seek immediate medical attention if you develop a sudden onset of fever, headache, stiff neck and vomiting.

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