Naegleria is a microscopic ameba commonly found in the environment. Only one species of Naegleria has been found to infect humans, Naegleria fowleri. Naegleria fowleri is found worldwide. Most commonly, the ameba is found in the soil and in warm, stagnant bodies of fresh water, such as lakes, rivers, and hot springs, unchlorinated swimming pools, and in warm wastewater pools from power plants.
Infections are rare.
The ameba enters the body through the nose and travel to the brain and spinal cord while the person is swimming underwater or diving. Headache, fever, nausea and vomiting, stiff neck, confusion, lack of attention to people and surroundings, loss of balance and bodily control, seizures, and hallucinations are signs and symptoms of infection. Do not swim in warm, stagnant, fresh water, such as ponds or wastewater discharge pools, or unchlorinated swimmimg pools.