Death by brain-eating amoeba reported at Renown

8 a.m. update:

A 21-year-old Bishop, Calif., resident died in Reno from an extremely rare infection called primary amoebic meningoencephalitis (PAM).

The woman was flown to Renown Regional Medical Center, where she experienced cardiac arrest and died June 20.

Her name is not being released by her family, Richard Johnson, M.D., of Inyo Public Health said.

Humans are infected by the amoeba, Naegleria fowleri, when swimming or diving in fresh, warm water. The amoeba then migrates through the nose and skull, where it reaches the brain and begins to destroy brain tissue.

"This is a very unusual biology lesson, but an extremely tragic one," Johnson said.

This is the first reported case of primary amoebic meningoencephalitis (PAM) in the eastern Sierras and in Bishop, but there have been seven previous cases in California, Johnson said.

The resident was believed to be infected on private land. The general public does not have access to the land and is safe from contracting the infection.

"Our next steps are to inspect the suspected sites of exposure to find what risk factors might exist like places where people might go swimming and where the domestic water supply is on the property," he said.

Commercial water sites with hot springs do not present a risk to the public because they are maintained well.

"I advise people to be cautious when using untreated hot springs in the Sierras," Dr. Johnson said, "The best way to do that is to keep your head above water."

Original update:

A 21-year-old Bishop resident died from an extremely rare infection called primary amoebic meningoencephalitis (PAM).

The resident first felt symptoms on June 16 including headache, nausea and vomiting, a report from the Division of Health & Human Services of Inyo County said. She was admitted to Northern Inyo Hospital, where she was diagnosed with meningitis. When her condition continued to deteriorate, she was flown to Renown Regional Medical Center, where she experienced cardiac arrest and died, the report said.

Testing by the Centers for Disease Control and Prevention was positive for the amoeba known as Naegleria fowleri.

Public health staff believe that she had exposure to the amoeba on private property and does not represent any risk to the general public. Investigations will continue and all appropriate measures will be taken to minimize risk in the future.

Humans are infected when water containing Naegleria fowleri enters the nose, usually while swimming or diving. The amoeba then migrates through the nose and skull, where it reaches the brain and begins to destroy brain tissue. The report said that the amoeba has never been shown to spread from one person to another.

This infection is extremely rare with zero to eight infections each year. Public health officer Dr. Richard Johnson said the risk of contracting the disease is extremely low, yet the stakes are high because the chance of dying once infected is almost 100 percent.

There have been no evident cases of amoeba contamination in the U.S. in well-maintained, properly treated swimming pools or hot springs, Dr. Johnson said.

For more information on the amoeba, visit www.cdc.gov/parasites/naegleria/index.html