Lakeside Amoeba

Warning: That next cannonball dive in the lake just might kill you. Still, that’s no reason to skip spring break in Lake Havasu . . .


Published by:Scottsdale Times, December 2007

To hear Sherene Zegler tell it, the night her nephew Aaron was helicoptered from Lake Havasu City to Sunrise Children’s Hospital in Las Vegas had all the baffling medical mystery twists of an episode of the hit show House.

“It all happened so fast,” says Zegler, a registered nurse and former Lake Havasu resident who now lives in Menifee Valley, Calif. “He was playing in the water on Saturday. On the following Saturday, he started having a low-grade headache. Woke up in the middle of the night with a splitter, and within 24 hours, he was dead!”

The whole tragic ordeal began as innocently as could be. On Saturday, Sept. 8, Aaron Evans, 14, was enjoying an afternoon swim out on Lake Havasu with his dad, his brother, Sam, 5, and his 3-year-old sister, Logan.

“Logan doesn’t like putting her head under water,” says Zegler. “Sam doesn’t like it either – he rarely gets his head in the water. But Aaron was the aggressive one. Played like your average 14-year-old boy.”

At some point during the day, Aaron apparently inhaled a nose full of water – which included, to no one’s knowledge, a microscopic amoeba called Naegleria fowleri. The organism, often abbreviated as N-fowleri, typically thrives on algae and bacteria at the bottom of shallow, warm lake water, but when stirred up by human activity, can enter the body through the nose and attack the brain.

Aaron’s dad, David, brought him into Lake Havasu Regional Hospital in the middle of the night the following Sunday after Aaron’s complaining of severe headaches. No one had any idea a tiny organism was burrowing its way through the young teen’s brain. At first, dad and mother, Caroline, assumed the headaches had something to do with Aaron’s adjusting to the new rubber bands that had been installed on his braces.

At the hospital, Zegler says, doctors pulled spinal fluid from Aaron and started him on antibiotics. “They were looking for bacterial meningitis – which is classic,” Zegler says, given the symptoms. At around 3 a.m., Zegler got a call from her sister telling her Aaron was being air evacuated to Sunrise Children’s in Vegas, a hospital known for its pediatric emergency unit.

Shortly thereafter, Zegler reports that David, who was with his son at the time, saw Aaron bolt upright, slump over and go into respiratory arrest.

“He had hemorrhaged at that point,” she says. “His right eye was blown, his pupil was dilated and fixed. They started CPR on him then put him on a ventilator.” Had he been in ICU, Zegler believes, doctors might have been able to monitor his intracranial pressure to tell them his brain was swelling.

Brain dead before the cause could even be determined, Aaron was taken off life support early the next morning. When word from the Centers for Disease Control and Prevention (CDC) came back identifying the cause of death as infection by Naegleria fowleri, even Zegler’s most experienced nursing colleagues heaved a collective “Huh?”

“I’m talking to nurses at my hospital, and they’re like, ‘Is this new?’” Zegler recalls. “Nobody’s even frickin’ heard of it!”

Even Zegler herself, a RN who commonly pulls three 12-hour shifts a week and serves as a captain in the USAF Reserves Nurse Corp, was unaware of the amoeba until her nephew’s death.

Since then, Zegler has been obsessively scouring medical journals and the Internet to learn all that she can about the organism, and has been shocked to learn specialists have known about this tiny killer since the ‘60s.

She knows infections from the amoeba are extremely rare: between 1995 and 2004, according to the CDC, only 23 cases were reported in the U.S. The infection occurs only through the nose – drinking water containing the amoeba won’t harm you – and chlorine and cold temperatures effectively kill it, leaving only untreated wells and the shallow edges of warm lakes as potential danger zones.

Still, with the exception of three, every reported case has proved fatal – no antibiotic has been found effective in stopping the amoeba faster than it spreads. And officials have noted a curious rise in cases this year, with three in Florida, two in Texas and now one in Arizona.

Given the amoeba’s hugely destructive potential, Zegler can’t understand why warnings about N-fowleri, rare as its attacks may be, aren’t at least as prevalent as peanut dust warnings on a Snicker’s bar, or hot beverage alerts wrapped around a Starbucks cup.

“This is not like spilling hot coffee in your lap at McDonald’s, where you can get burned,” Zegler says. “With this one, you get dead.”

Spring Break-er

Had David Evans known more about N-fowleri, Zegler insists, her sister’s ex-husband never would have let his son dunk his head in the shallow regions of Lake Havasu that day.

“David has said, emphatically, that had he known about this, he would never have allowed his children’s heads to go under that water,” says Zegler. “I’ve talked to parents out here in Menifee who frequent Havasu, who now say, ‘My children are never going in that water – period.’”

Of course, that’s precisely the reaction Lake Havasu City is hoping to avoid. Although the City Council voted in mid-October to begin posting warning signs about the dangers of the rare amoeba around the city’s part of the lakefront, many local business owners have expressed concern that too much publicity over the freak incident could scare visitors away from the popular water recreation spot, which annually draws over 2.5 million tourists.

One marina owner, recalling the economic toll his business took in the early ’90s when water quality tests revealed high levels of E. coli in a popular section of the lake known as the English Channel, told local reporters he’s seeing a return to that same fearful public mindset from which his marina took three years to recover.

“We are a community that depends on water recreation,” says Lake Havasu City spokesperson Charlie Cassens, who admits he’s been fielding calls from the media ever since the Evans case made national news. “So it is kind of unfortunate that Lake Havasu is taking the rap for this thing, when in fact, this is a condition that could happen almost anywhere, at any time.”

Well, any place where water temperatures commonly exceed 80 degrees, qualifies Cassens, who, like Zegler, has had to take a crash course on the amoeba to handle all the inquiries streaming in. Growth of the bacteria that N-fowleri feeds on increases as surface water heats up, which explains why cases have been limited to water bodies in the hotter southern states.

In fact, Arizona has seen more than its share of N-fowleri cases in recent years. In 2002, two Peoria boys died after accidentally inhaling the organism through non-chlorinated water in the city’s water supply (the supplier, Rose Valley Water, began treating its system immediately after and residents were advised to avoid immersing in the tap water until tests were conducted by the CDC and state and county health departments). And just last month, University of Arizona microbiologists found some presence of the amoeba in 12 of the 35 Tucson water wells it tested, although the city has stated its well water is safely chlorinated before distribution.

If anything, experts feel the Arizona cases should be studied as models of where the rest of the globe may be heading if the planet continues to heat up. For all the vague warnings we’ve been hearing about global warming, the brain-eating amoeba may actually represent the first concrete, if freaky, example of possible weird mutations.

“This is a heat-loving amoeba,” says Michael Beach, a specialist in recreational water-born illnesses for the CDC in Atlanta. “So one would expect, as water temperatures go up, the amoeba will grow better or appear in lakes where it wasn’t before. And the numbers of infections may well go up.”

By erecting warning signs around Lake Havasu, Cassens feels his city is “stepping up” to educate the public on the dangers of this rare killer. But both he and city manager Richard Kaffenberger hope the municipalities around other U.S. lakes won’t let Havasu take all the heat.

“We’re hoping other states will follow our lead on this, and let people know this can be present in areas all over the world where there’s warm water,” Cassens says. “I had a caller the other day tell me she’s not going to swim in this lake anymore, and I asked her, ‘Well, what lake are you going to swim in?’ It’s important people know that it’s not just Lake Havasu’s problem.”

You Get it, You Die

Dr. Charles P. Gerba is probably the nation’s leading authority on waterborne diseases. Prior to taking the helm at the University of Arizona’s Department of Soil, Water and Environmental Science, he studied virology and epidemiology at Houston’s Baylor College of Medicine, garnered over a dozen awards in water science and literally helped write the book the EPA uses for testing water treatment devices used for outdoor recreation.

But in conversation, the professor – who prefers answering to “Chuck” and comically dismisses the more than 400 articles he’s authored on environmental microbiology as “a lot of toilet papers” – is refreshingly down-to-earth when asked how worried we should be over the current amoeba scare.

“I’ve studied recreational waters for so long – Slide Rock, lakes, what have you – that every butt crack is pretty scary to me,” he says, with a laugh. “Basically, you’re taking a risk of contacting germs whenever you enter a fresh water recreational area. And to most people, that’s an acceptable risk. But with this one, it’s a little different. Because if you get it, you die!”

Gerba, who led the team of microbiologists who found traces of N-fowleri in the Tucson water wells, says children between the ages 12 and 18 seem most at risk for the infection (adults have stronger antigens in the blood to counteract it), and that boys are the most common victims, possibly because they’re more apt to roughhouse in the water.

The good news is there are some simple, basic precautions people can take to avoid getting a gush of the deadly amoeba up the nostrils.

“First, try to keep the kids from submerging a lot in shallow waters,” Gerba suggests. “I know they won’t like it, but try to get them to wear nose plugs. Either that, or, if they want to roughhouse, do cannonballs and jump and get their noses full of water, take them to a chlorinated swimming pool.”

Gerba hopes the medical community will become more knowledgeable about the organism, and begin testing for it whenever meningitis is suspected, as the infection often apes those symptoms.

“These microbes aren’t going away,” he says. “In fact, they’re increasing in number, and doctors need to learn more about them.”

As for lakes ridding themselves of the amoeba, the CDC’s Beach says that’s not likely to occur.

“Because it’s a natural environmental contaminant, it’s unlikely we will ever be able to eliminate it from these lakes and rivers,” Beach says. “All we can do is reduce risk by avoiding swimming in areas that are very shallow and very warm, by not putting our heads under the water when we’re stirring up sediment, and by closing our noses if we do happen to go underwater.”

Information like that, says Sherene Zegler, might have been all her nephew needed to stay healthy on that fateful Saturday afternoon.

“People are getting this information now, and making their own decisions about what they’re allowing their children to do in the water,” Zegler says. “Some are reacting in the extreme. Others are saying it’s so rare, they’re not concerned about it.

“But you’ve got to let people make their own decisions, based on what you know is in that water,” she adds. “I mean, better they hear about that than about another child dying in your lake.”


Photos by Hector Acuna, Matthew Casey

Signs like this one are being erected at state lakes warning swimmers of the danger of the microscopic amoeba.

The deadly Naegleria fowleri.

Sherene Zegler's 14-year-old nephew died after inhaling one of the amoebas while swimming at Lake Havasu: "This is not like spilling hot coffee in your lap at McDonald’s."

Dr. Charles P. Gerba, a leading authority on waterborne diseases at Arizona's Department of Soil, Water and Environmental Science: “These microbes aren’t going away.”

Boaters at Lake Havasu. “Some are reacting in the extreme. Others are saying it’s so rare, they’re not concerned about it," says Sherene Zegler.