Lake Elsinore boy, 9, dies of infection by water-borne amoeba

Authorities said it was unknown exactly where the 9-year-old boy contracted the deadly Naegleria fowleri amoeba. He had gone swimming in Lake Elsinore several times this summer.

The parasite lives in warm freshwater lakes, rivers and poorly maintained swimming pools, experts say. It enters the brain through the nose, where it can cause a severe and nearly always fatal infection. This is the county's first confirmed case of the illness.

"The risk of infection is extremely low and is no different in Lake Elsinore than in any other warm-water lake," said Dr. Eric Frykman, Riverside County public health officer. "This is not a new risk, but because of the unique nature of it and because it is fatal we wanted to get this information out to the public."

There were 33 reported cases of infection in the U.S. from 1998 to 2007, the Riverside County Department of Public Health said. Symptoms of infection by Naegleria, which can kill in three days, include headache, fever, nausea, vomiting and a stiff neck.

Frykman said that children seemed more susceptible to the illness than others but that this could be because they are in the water more often.

To lessen the chance of coming into contact with the amoeba, Frykman suggested the following:

* Avoid warm fresh water, hot springs or water around power plants.

* Avoid the water when temperatures are high and water levels are low.

* Hold your nose shut while in the water or use a nose clip.

* Don't dig or stir up sediment while in shallow, freshwater areas.

david.kelly@latimes.com