EL CAJON -- Water skiing wakeboarding and fishing were things Kelsey McClain lived for.
"Pretty much anything to do with the outdoors, she loved," said McClain's mother, Jennifer McClain.
But she also died by the outdoors.
In August 2015, McClain celebrated her 24th birthday at Fisher's Landing, a resort along the Colorado River that's about a three-and-a-half hour drive from San Diego. She felt fine when she got back home to El Cajon, but that changed a few days later.
"With what she described as a pounding headache," her mother said.
Prescription painkillers hardly helped. McClain woke up the next morning unable to speak or move her head. Doctors admitted her, suspecting bacterial meningitis.
"It was apparent to everyone this was progressing," Jennifer said.
Multiple antibiotics failed, and McClain's condition worsened.
"She had a full grand mal seizure," Jennifer said.
Eight days after she got back from celebrating her birthday, McClain was brain dead.
"My life is ruined, destroyed," Jennifer said. "I have two other daughters, but it doesn't matter."
Doctors were baffled. They sent McClain's spinal fluid to a lab at UC San Diego, and what they discovered halted her organ donation.
"They came back very quickly with it was a parasitic amoeba," Jennifer said.
McClain was stricken by Naegleria fowleri, a brain-eating amoeba found in freshwater rivers, hot springs and lakes. There are about 20 of those in San Diego County, many without warning signs. The amoeba enters through the nose, according to health experts.
There have been 133 recorded cases in 50 years. Three people survived, including an Arkansas girl who underwent months of rehab.
Shirley Bush, a partner at Fisher's Landing, said the disease is so rare that they hadn't even heard of it until McClain caught it in the waters off their resort. Bush said they have since posted some warning signs and may sell swimmer's nose clips in the gift shop.
"Anybody that comes here, residents of ours or not, it doesn't matter. We care and do our best effort to keep them informed," Bush said.
McClain's mother said her family is devastated.
"She was just sort of the glue, of our family, really," Jennifer said, "Just sort of this nice, happy medium between her two sisters. I think it made all of us better."
Now, she's on a mission to prevent others from catching the amoeba. One way for people to protect themselves is to wear swimmer's nose clips, available for about $4. They keep the water from forcefully going up a swimmer's nose.
That may be the most people who go under water can do.
Jeffrey Engel, who directs the Council of State and Territorial Epidemiologists, said the disease is too rare and preventable to be placed on a notification list it maintains. It most recently added Zika.
"What would the intervention be?" he said. "We would never close all fresh water swimming areas; that would be impossible. There's no intervention to prevent."
Still, with travel season upon us, Jennifer wants others to be aware of what could be in the water.
Here's what you need to know if you decide to visit a body of fresh water:
Prevention: The CDC says the only way to fully avoid the risk is to avoid water related activities in warm freshwater. If people choose to swim, they should use swimmer's nose clips or hold their nose shut when going under water. Those who use neti pots to clean their nostrils should boil water and then let it cool. The CDC has fact sheets for best ways to prevent catching the amoebas.
Treatment: There is no known treatment for killing the amoeba. However, an experimental breast cancer drug called Miltefosine has been shown to kill the amoeba in the lab. Doctors say early detection is key. Engel said he doesn't see drug companies developing a specific treatment to the amoebas anytime soon -- it's just too rare.