The headlines sound like something out of a science fiction-horror movie:
Fourth Brain-Eating Amoeba Case of the Year Being Treated
Is There a Brain-Eating Amoeba in Utah?
S.C. Girl Dies After Contracting Brain-Eating Amoeba in River
Brain-Eating Amoeba Detected in Waters of Wyoming’s Grand Teton National Park
We are told cases are rare, but the stories are enough to make one want to avoid the water forever.
This summer, so far there have been four reported cases of infection with the deadly brain-eating amoeba called Naegleria fowleri.
Currently, an unidentified person in Florida is being treated for infection, CNN reported today.
And just last week, Hannah Collins, 11, of South Carolina, died after contracting Primary Amebic Meningoencephalitis (PAM), which is a severe brain infection caused by the amoeba.
Hannah was likely exposed to the organism on July 24 while swimming near Martin’s Landing on the Edisto River in Charleston County, the South Carolina Department of Health and Environmental Control said in a news release.
She is the second person to die after contracting PAM in the Carolinas this summer. In June, 18-year-old Lauren Steiz of Westerville, Ohio, died after contracting the amoeba infection at the U.S. National Whitewater Center in Charlotte, North Carolina. The high school senior had visited the water park on a church trip. At one point, she was riding on a raft that overturned, health officials said.
In July, the amoeba claimed the life of Hudson Adams, a 19-year-old who became infected at a Texas lake.
Writer JoAnna Klein happened to be at the U.S. National Whitewater Center in NC around the same time as Steiz. After returning home she learned of the young woman’s death, and wanted to learn more about the deadly amoeba.
In My Vacation With a Brain-Eating Amoeba, Klein writes that samples from a channel at the rafting center, collected by the Centers for Disease Control and Prevention, tested positive for the amoeba:
Sediment from the nearby Catawba River, where visitors to the center can paddle board and kayak, also tested positive for the amoeba, although the actual water from the river did not test positive. Dr. Jennifer Cope, an epidemiologist at the C.D.C., said natural bodies of water might have their own ways of controlling the bug. The parasite possibly entered the artificial river through storm water runoff or people tracking it in on their shoes, said Dr. Cope.
Between the time of the young woman’s visit in early June and when the whitewater center voluntarily shut down its rafting activities a few weeks later, thousands of people could have been exposed to the parasite, but there were no additional reports of infections.
“The interesting thing about this infection is it’s almost always one single case that occurs in one location,” said Dr. Cope.
Rare, But Deadly
According to the Centers for Disease Control and Prevention (CDC), there have been 138 PAM infections in the US from 1962 through 2015. Only three of those infected survived.
The infections primarily occurred in 15 southern-tier states, with more than half occurring in Texas and Florida. PAM also disproportionately affects males and children. The reason for this distribution pattern is unclear, reports the CDC, but may reflect the types of water activities (such as diving or watersports) that might be more common among young boys.
Between 2006 and 2015, there were 37 documented infections, mainly associated with recreational swimming, but one involved contaminated water on a slip-n-slide, and three cases were from rinsing sinuses with infected tap water, including two involving Neti pots.
Ninety-seven percent of people who contract the disease don’t survive.
Symptoms of Infection
Naegleria fowleri symptoms typically start 1-9 days (median 5 days) after exposure, and can mirror bacterial meningitis, which can make diagnosis tricky. This is unfortunate, because the disease progresses rapidly – so rapidly, in fact, that diagnosis is usually made after death.
Death occurs within 1 – 18 days (median 5 days) after symptoms begin.
Individuals usually become infected while swimming in warm fresh water. The amoeba enters the nose and then travels to the brain, where it causes swelling and tissue death.
Signs and symptoms of infection include:
- Stage 1
- Severe frontal headache
- Loss of appetite
- Stage 2
- Stiff neck
- Altered mental status
There may also be hallucinations, drooping eyelids, blurred vision, and loss of the sense of taste.
Diagnosis and Treatment
Infection is diagnosed using specific laboratory tests available in only a few laboratories in the United States.
Klein spoke with Dr. William Matthew Linam, a physician at Arkansas Children’s Hospital, and reports that the sooner one is diagnosed, the better:
If you’ve been playing around in warm fresh water, especially during summer months, and come down with a headache, fever, nausea or vomiting, experts say to tell your doctor where you’ve been.
Dr. Linam told Klein he believes early detection is critical, and he would know: In 2013, he saved 12-year-old Kali Hardig, who was exposed to the lethal amoeba at an Arkansas water park. Hardig is one of the only three documented survivors in the US. Dr. Linam called the CDC immediately, and the amoeba was found in a sample of the girl’s spinal fluid.
Last year, in their coverage of Hardig’s intriguing story of survival and the published study of her case, Newsweek explained her treatment protocol:
Doctors at Arkansas Children’s Hospital put the girl on a cocktail of antibiotics. They also phoned the CDC, requesting an experimental drug called miltefosine that had been shown to have some activity against amoebae, and this experimental pharmaceutical arrived a day and a half later.
As explained in the study, authored by scientists and physicians including Dr. Matt Linam, who treated Kali, the main key to her survival was quick detection. She was put on antibiotics within about six hours of admission, and the miltefosine 24 hours after that.
The team also induced hypothermia by putting chilled pads on the outside of her body, lowering it to 90 degrees Fahrenheit. This is sometimes done with patients who have traumatic brain injuries. The procedure may help reduce swelling and herniation in the brain, which is ultimately what kills people with this infection, says Jennifer Cope, a study co-author and medical epidemiologist for the CDC in Atlanta.
“She survived from a combination of early recognition and diagnosis, and aggressive treatment,” Cope says.
Also in 2013, an 8-year-old boy in Texas who was treated with miltefosine survived, although he suffered brain damage. That outcome was believed to be due to the fact that he was not treated until “several days after his symptoms began” and his body temperature was not lowered, according to the CDC.
The only other known survivor in the US (who was not treated with miltefosine) was a patient in California in 1978.
Where are brain-eating amoebas found?
Naegleria loves very warm water. It can survive in water as hot as 113 degrees Fahrenheit.
These amoebas can be found in warm places around the globe. According to WebMD, N. fowleri is found in:
- Warm lakes, ponds, and rock pits
- Mud puddles
- Warm, slow-flowing rivers, especially those with low water levels
- Untreated swimming pools and spas
- Untreated well water or untreated municipal water
- Hot springs and other geothermal water sources
- Thermally polluted water, such as runoff from power plants
- Soil, including indoor dust
N. fowleri has been detected in water systems. Last year, two water systems in Louisiana tested positive for the amoeba.
Health officials advise that people should be aware of the risks of swimming in lakes and rivers and try to limit how much water goes into their noses by holding it while jumping in or using a nose plug.
Most cases of N. fowleri disease occur in southern or southwestern states. Over half of all infections have been in Florida and Texas, but the organism has been detected as far north as Minnesota.
The amoeba was recently detected in Grand Teton National Park in Wyoming. United States Geological Survey researchers have also found the amoeba in streams and pools near to Kelly Warm Spring and in Huckleberry Hot Springs and Polecat Springs in the John D. Rockefeller Parkway between Grand Teton National Park, and Yellowstone National Park. Wading or swimming is not allowed in those springs.
How common are infections?
Infection with N. fowleri is considered rare, but some cases may go unreported. A study in Virginia that reviewed more than 16,000 autopsy records from patients who died of meningitis found five previously unreported cases of PAM.
Studies show that many people may have antibodies to N. fowleri, reports WebMD. This suggests that they became infected with the amoeba, but their immune systems successfully fought it off.
There’s still a big unknown: Is N. fowleri a rare infection that always causes PAM and is almost always fatal, or is it a more common infection that only sometimes causes PAM?
A 2009 CDC study suggested that the common finding of antibodies to the amoeba in humans and the frequent finding of N. fowleri in US waters indicates that exposure to the amoeba is much more common than the incidence of PAM suggests.
Personal actions to reduce the risk of Naegleria fowleri infection should focus on limiting the amount of water going up the nose.
These actions could include:
- Hold your nose shut, use nose clips, or keep your head above water when taking part in water-related activities in bodies of warm freshwater.
- Avoid putting your head under the water in hot springs and other untreated thermal waters.
- Avoid water-related activities in warm freshwater during periods of high water temperature.
- Avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.
Although very rare, Naegleria fowleri has caused deaths associated with tap or faucet water going up the nose. It can grow in public and private water tanks and pipes, especially where little or no disinfectant (like chlorine or chloramine) is present. It can also grow in the pipes and hot water heaters of homes and buildings, according to the CDC.
Naegleria fowleri infections have been reported when people put their heads underwater, rinse their sinuses through the nose (as in the use of Neti pots), and cleanse their noses during religious practices using contaminated tap or faucet water.
It couldn’t hurt to keep the following precautions – which were provided to Louisiana residents last year – in mind:
- DO NOT allow water to go up your nose or sniff water into your nose when bathing, showering, washing your face, or swimming in small hard plastic/blow-up pools.
- DO NOT jump into or put your head under bathing water (bathtubs, small hard plastic/blow-up pools); walk or lower yourself in.
- DO NOT allow children to play unsupervised with hoses or sprinklers, as they may accidentally squirt water up their nose. Avoid slip-n-slides or other activities where it is difficult to prevent water going up the nose.
- DO run bath and shower taps and hoses for five minutes before use to flush out the pipes. This is most important the first time you use the tap after the water utility raises the disinfectant level.
- DO keep small hard plastic/blow-up pools clean by emptying, scrubbing and allowing them to dry after each use.
- DO use only boiled and cooled, distilled or sterile water for making sinus rinse solutions for neti pots or performing ritual ablutions.
- DO keep your swimming pool adequately disinfected before and during use.
- If you need to top off the water in your swimming pool with tap water, place the hose directly into the skimmer box and ensure that the filter is running. Do not top off the pool by placing the hose in the body of the pool.
Remember, if infection is suspected, immediate medical care is critical to survival, and even then, there are no guarantees. Following preventive measures is a good idea. If warning signs are posted, follow them, and if they aren’t, don’t assume a body of water is safe for swimming.