A boy has died after exposure to a rare brain-eating parasite at Lake Mead, the popular recreation area near Las Vegas, health officials say.
The brain-eating amoeba, known technically as Naegleria fowleri, enters the body through the nose and can cause inflammation, seizures, coma and usually death.
Health officials say it flourishes in warm, fresh-water environments.
It's believed to be the only case of the parasite associated with Lake Mead and only the second in Nevada's history, according to state and local health officials.
California has had 10 reports of the parasitic infection since 1962, according to the CDC.
The boy, who lived in the Las Vegas area and whose exact age was not given, was believed to have visited the Arizona side of Lake Mead in early October. He began developing symptoms about a week later, according to the Southern Nevada Health District.
The district says: "The amoeba is naturally occurring, and there is no routine test for Naegleria fowleri. Previous water testing has shown that it is regularly found in freshwater bodies and though the risk is low, recreational water users should always assume there is a risk when they enter warm fresh water."
Although infection is often fatal, there are some rare treatments available.
"With a parasite, you can't kill it with antibiotics, you can't kill it with antivirals, and we don't have a vaccine for this so we have to use rare antiparasitic medication," said family physician Dr. Daliah Wachs.
Officials say there's no danger of the amoeba getting into Las Vegas' drinking water supplies.