The Associated Press

MIRRIETA, Calif. — A veteran Murrieta firefighter has died after being infected with a rare brain-eating amoeba that usually lives in soil, the city Fire Department said in a statement Tuesday.

Capt. Matt Moore died Monday at UC San Diego Medical Center Hillcrest from complications of meningoencephalitis. The 43-year-old father of three had been in a coma.

"He was one of our best," said Fire Chief Paul Christman. "We're going to miss his presence in our ranks greatly."

A funeral cortege returned his body to Murrieta Wednesday.

Moore first fell ill in November. A biopsy showed in January that his brain had been invaded by the parasite Balamuthia mandrillaris.

The disease was first identified in 1990 after a mandrill baboon at the San Diego Wild Animal park was infected.

Doctors aren't sure how the parasite infects humans, but an infectious-disease expert said it appears that only people with weakened immune systems are at risk.

"When you think about the number of people who are exposed to dirt, it's very, very rare," said Sharon Reed, a professor of pathology at the University of California, San Diego. "This isn't cause for huge hysteria."

More than 100 cases have been reported. A 2004 study by the Centers for Disease Control in Atlanta showed the amoeba is particularly prevalent in California, where at least 11 cases have been reported.

Reed said the data may be skewed by the fact that doctors in California are more aware of the disease and therefore likelier to spot its victims.

All but two cases have been fatal, Reed said.

The parasite can remain dormant for an unknown period, Reed said. The amoeba typically cluster around blood vessels in the brain and destroy surrounding cells.

"It's devastating for the families because the outcome is so grim," Reed said.