CHARLESTON, SC (WCSC) - On strings of hot summer days, kids head to the nearest swimming hole, but there are hidden dangers in fresh water, that over the years, have taken the lives of four children.
A microscopic amoeba some call the brain-eating amoeba has caused rare, but deadly brain infections in these children.
"It's not rare when it happens to you," said Dunn Hollingsworth who lost his 10-year-old daughter, Liza, to the amoeba.
Gingi Driggers lost her 8-year-old son, Blake.
"There are lots of families that have lost loved ones to this amoeba who never thought something like this would happen to them," Driggers said.
It is difficult for the parents to talk about. Hollingsworth wiped tears away as he described what happened in the summer of 2010.
But these parents don't want it to happen to you, and with the help of Dr. Terry Dixon, they're teaching us about Naegleria Fowleri, the so-called brain-eating amoeba.
It's out there.
Dr. Dixon of the Medical University of South Carolina said it exists in just about every freshwater source you can find.
According to the Centers for Disease Control, you should assume Naegleria Fowleri is present in warm freshwater across the United States.
That means it is found in lakes, rivers, hot springs, swimming pools not chlorinated correctly, contaminated tap water, and the soil.
We see cases in hot summer months.
"It can be more abundant in numbers on very hot days because it really likes heat," Dr. Dixon explained
Liza Hollingsworth was at a summer birthday party in 2010.
"They were taking paddle boarding lessons at a pond in the neighborhood in Mount Pleasant and splashing around and jumping in water that was chest high for them," her father said.
The most recent case was Hannah Collins in 2016 after she went swimming in the Edisto River. For Marissa Cook-Norris, a suspected case in 2007, it was a boating trip in Lake Marion.
Another family boating trip in Lake Marion led to Blake Driggers' infection and death in 2012.
"I think whenever Blake jumped off the dock is when he got a blast of water up his nose, and that's when he contracted it," his mother said.
Infection happens when contaminated water goes up the nose. The amoeba travels to the brain and causes Primary Amebic Meningoencephalitis or PAM.
"It just emits substances that cause the brain tissue to dissolve and you get swelling from that," explained Dixon.
Symptoms start one to nine days after infection.
Driggers said for her son, the earliest symptoms looked like a stomach bug. Hollingsworth described his daughter's early symptoms as a "summer bug."
"Liza said she didn't feel good, her head hurt and she wanted to go lie down," said Hollingsworth.
Over the next few days, experts say there can be neck stiffness and an altered mental status.
"It happens very fast, that's why it's so critical when they start showing signs, you immediately get them checked," Driggers said.
It's vital to tell the medical experts about being in fresh water so doctors can perform a spinal tap.
"When the lab is alerted there is a freshwater exposure, the lab technicians are well trained in how to look for this amoeba," Dr. Dixon said.
But that's not the case at every hospital, and diagnosis often comes too late.
Now there's a professional online video by the Jordan Smelski Foundation, teaching labs what to look for. Aggressive treatments, including the drug miltefosine, have saved a few patients. While the drug is on hand at MUSC, it's impossible to predict if it will be needed.
There were no cases in the US last year and eight in South Carolina over the last 48 years.
According to the CDC, there is no way to accurately measure how many are in the water, and they don't know why some people are infected, while millions of others swimming in fresh waters, are not.
"It's really like playing Russian Roulette because we had a lot of people jumping in that didn't get it in the same area at the same time," Driggers said.
That's why she, and health experts, recommend wearing nose plugs when you're in the warm fresh water, or a heading instead to a properly chlorinated swimming pool, or, salt water where the amoeba is not found.
But Hollingsworth suggests alternatives.
"If it's rare, how about if we can make it more rare and unlikely to happen by trying to avoid those circumstances...go to the beach," he said.
There have also been deaths, three of them, in people who have used neti pots with non-sterile tap water, and one death from a backyard slip-n-slide.
The tap water, in that case, was contaminated. In all, in ten years across the US, 40 infections have been reported.