ST. PAUL, Minn. — It wasn't clear what kind of monster was inside Annie Bahneman until an autopsy revealed the presence of a rare brain-eating amoeba.
It wasn't clear when the 7-year-old's fever hit 104 degrees and she started throwing up and couldn't stop. Or when she lay seizing in her mother's arms as her father raced the family car from Stillwater to Children's Hospital in St. Paul.
But Annie's parents, Chad and Bridget Bahneman, knew something was horribly wrong when a delusional Annie asked why there were animals in her hospital room.
“At one point, she sat up and said, 'My head hurts terrible,' ” Bridget Bahneman said. “She started to seize every hour. Then she quit talking. She never woke up.”
Annie died Aug. 21, 2010, her death attributed to Naegleria fowleri, a vicious parasite that lives in warm freshwater all over the world and is harmful when it enters the human body through the nose. Between 1962 and 2012, there were 128 cases of the parasitic infection reported in the United States, mostly in the South. Only one person survived.
The parasite was later found in Stillwater's Lily Lake, where Annie had been swimming.
Hers was the first confirmed case of the infection in Minnesota, the official cause of her death being primary amebic meningoencephalitis, also called PAM.
But it would not be the last.
Two years later, 9-year-old Jack Ariola Erenberg died of the same infection after swimming in the same lake. Two other children's deaths may also have been caused by the parasite after swimming in Minnesota lakes.
The unimaginable horror of a child suffering and dying after pursuing one of Minnesota's most treasured summer pastimes raises questions of: Why here? Why now? And, more important, what can we do?
Health experts and government officials contacted for this report offer some ideas.
The appearance of Naegleria fowleri in Minnesota has piqued officials' interest because it indicates its geographic range is spreading northward.
“It's rare to begin with, no matter where you are in the country, but certainly physicians in Texas or Florida think of it more often than physicians in Minnesota,” said Jennifer Cope, an epidemiologist and infectious-disease physician with the U.S. Centers for Disease Control and Prevention in Atlanta.
Mark Schleiss, head of the University of Minnesota Medical School's division of pediatric infectious diseases and immunology, said Annie's and Jack's deaths have prompted an effort to educate medical professionals to be on the lookout for symptoms.
“It is on people's radar,” Schleiss said.
He said the emergence of the amoeba in Minnesota may have other implications.
“(It) may speak to climate change. I don't think there's any scientific question about that,” Schleiss said. “It's a reflection of man-made climate change leading to this change in epidemiology.”
Experts are learning more about the ecology of the amoeba and what triggers it in particular waters and people.
To help, Washington County is working with the CDC to sample local lakes.
“We're trying to advance the science of detecting ... how to sample and how to analyze samples and what to look for,” said Lowell Johnson, director of the county's public health department. “How can we be in a better position in the future — to have either better science or better understanding around what lakes present a significant risk versus which ones do not?”
Health officials sampled three sites where Annie Bahneman swam before her death: Lily Lake, Little Carnelian Lake and the St. Croix River. Only Lily tested positive for the amoeba, Johnson said.
Testing of Washington County lakes has continued annually since then. In 2011, the department tested 10 lakes in Washington County. Six tested positive for Naegleria fowleri — Big Carnelian, Little Carnelian, Lake Demontreville, Lake Elmo, Big Marine and Lily Lake; there was no detection in Bone Lake, Forest Lake, Goose Lake and Square Lake, Johnson said. A year later, the same 10 lakes were tested, but only Lily tested positive. And this year, none of the lakes tested positive.
Researchers still don't know why there are variations from year to year and even in the same body of water.
Jonathan Yoder, who heads the CDC's domestic water, sanitation and hygiene epidemiology team, said the amoeba thrives in water up to 115 degrees. At lower temperatures, the amoeba becomes less active and may die, but there are still many unknowns, like how the organism survives the Minnesota winter.
Washington County health officials have been sharing their experiences with other counties.
“Everything we're being told is that if it could be in freshwater in our county, it could be in freshwater anywhere,” Johnson said.
Chad and Heidi LaMeyer, who live in Columbus, Minn., believe Naegleria fowleri infections aren't as rare in Minnesota as people believe.
In addition to Annie's and Jack's deaths, the LaMeyers believe there have been two others. One of them was their 11-year-old daughter, Hailee, who died in 2008 of meningoencephalitis after swimming in Fawn Lake in Stacy, Minn.
Another boy, 6-year-old Mason Faubel of Missouri City, Iowa, died in June 2011 at Children's Hospital and Medical Center in Omaha after a brief illness consistent with PAM. Mason and his family had just spent a week at a rental cabin on Island Lake west of Bemidji.
Although it was not officially confirmed, health officials later told the family that the likely cause of Mason's death was PAM caused by exposure to Naegleria fowleri, said his mother, Elizabeth Faubel.
The CDC's Yoder said it's difficult to confirm some suspected PAM deaths after the fact because tissue samples are required.
Heidi LaMeyer said Minnesota Health Department officials told her they suspect Naegleria fowleri caused Hailee's death but cannot confirm it because an autopsy wasn't performed.
Doug Shultz, a spokesman for the department, would not comment. He said only two deaths in the state have been confirmed to be caused by PAM.
The LaMeyers are helping run a nonprofit organization, Swim Above Water, dedicated to raising awareness of Naegleria fowleri and PAM and advocating for treatment and cure.
“One of our main goals is to move along research for the cases that don't have the confirmation,” Heidi LaMeyer said. “If they don't have an accurate number, how can they continue to call this so rare?”
HOPE FROM A NEW DRUG
The CDC has confirmed four cases of PAM in the U.S. this year, and in two of those cases an experimental drug was used that offers hope.
A 12-year-old LaBelle, Fla., boy contracted the parasitic infection after kneeboarding in a water-filled ditch by his house Aug. 3; he died three weeks later. A 4-year-old Mississippi boy also died in August after contracting the infection while visiting near Violet, La., and getting contaminated water from a Slip 'n Slide up his nose.
But there was also a glimmer of good news: A 12-year-old Arkansas girl named Kali Hardig survived the infection with the help of an experimental drug called miltefosine. And an 8-year-old Texas boy contracted PAM in Mexico and, as of Monday, remained in treatment in a San Antonio hospital. He also received miltefosine.
The drug has previously been used on a trial basis to combat other parasitic infections and breast cancer. It's not licensed or approved for use in the U.S., but the CDC can provide it to physicians who are treating free-living amoeba infections.
In the case of Kali Hardig, miltefosine was used as part of an overall treatment strategy that included reduced body temperature, antifungal medication and antibiotics.
Health officials, while hopeful, say there's a lot yet to learn.
“Obviously the gold standard would be to prevent all these infections. But it's rare, and we still don't know why the people that get it get it,” Cope said. “As we know, (the amoeba) is everywhere. There are hundreds of millions of swimming visits every year, but why do only a handful of people get (the infection)? Answering that question would be key to preventing deaths. But the position we're in now is that people are going to be infected. That's why we're working on the drug: because we want to save the lives of those who do get infected.”
The news that Kali Hardig survived PAM brought the LaMeyer family to its knees “in prayer and joy and pain,” Heidi LaMeyer wrote in an Aug. 10 post on Swimabovewater.org.
“We are overjoyed!” she wrote. “With that, though, comes overwhelming sadness for our great and terrible loss. We wish so badly that Hailee could have been spared. We know that there is nothing that will change that outcome, but human nature dictates that we are bound to feel mixed emotions right now.”
The Bahnemans regularly visit Annie's grave at Fairview Cemetery in Stillwater. They ride their bikes and Big Wheels, have picnic dinners, play tag, jump in leaf piles and make a toboggan run. They pick out a pink pumpkin to decorate Annie's grave at Halloween, cut down a tree for Christmas and make a heart in the snow for Valentine's Day.
“This is Annie's island,” Chad Bahneman said during a late-afternoon visit on Monday. “That's our sledding hill. We kind of make a toboggan course through the tombstones. We start up on the hill, and we end up coming down on this road.”
Chad Bahneman said he can't help but wonder, “What if?”
“If we had just made one decision different,” he said. “If she didn't swim that day or she had been wearing nose plugs or if we were swimming in a different part, things could have been different. It's just little things like that, you know. A little decision could have changed everything.”
Like LaMeyer, Bridget Bahneman said the news about Kali Hardig has been bittersweet.
“I'm thrilled that there might be hope for other families, but I can say, with my full heart, that I wished they had discovered it five years ago, and that we would have been that family that ended up with a happy ending.”
HOW TO PROTECT YOURSELF
The amoeba Naegleria fowleri thrives in warm bodies of freshwater and sediment. Infections are most common between July and September, when air and water temperatures have been high for prolonged periods. The amoeba causes a deadly infection only when it enters the body through the nose. From there, the parasite travels through olfactory glands to the brain. It cannot spread from person to person.
– The only certain way to escape infection is to avoid swimming and other activities in warm freshwater.
– Swimmers are cautioned to avoid lakes, rivers and hot springs during heat waves or periods of low water levels.
– If you swim, avoid getting water up your nose by keeping your head above water, holding your nose shut or wearing nose clips. Also avoid stirring up the sediment.
– Naegleria fowleri has also occasionally been found in tap water. Tap water used in Neti pots should be boiled or run through a filter with a pore size of 1 micron or smaller.
Source: Centers for Disease Prevention and Control