(CNN) -- A weekend swim left a young girl fighting for her life when she contracted a brain-eating amoeba with a 97% fatality rate.
The 10-year-old girl swam in the Brazos River and Lake Whitney in Bosque County near Waco over Labor Day weekend, according to CNN affiliate KWTX-TV.
Then, on September 8, the girl "began having a headache, and it was quickly followed by a fever," according to a Facebook page created to support the girl. Her family thought it was a viral infection at first, but after visits to the family doctor and the girl having trouble sleeping, the family knew something was wrong.
"She was incoherent, unresponsive and was quickly swept up and taken to the ER," the family wrote on the girl's Facebook page.
The girl was then flown to Cook Children's Health Care System in Fort Worth where a spinal tap found she had contracted Naegleria fowleri.
"It's every parent's worst nightmare," the girl's aunt, Crystal Warren, told KWTX Friday. "For this to happen to her when there were so many other people in the same waters on the same days we just don't understand why it was her."
The Centers for Disease Control and Prevention says the amoeba is a single-cell living organism commonly found in warm freshwater like lakes and rivers. The amoeba enters the body through the nose, travels to the brain and destroys brain tissue, according to the CDC.
Between 2009 and 2018, the CDC says only 34 cases of the Naegleria fowleri infection were reported in the US. Only four people out of the 145 known cases survived between 1962 and 2018.
Warren told KWTX she's hopeful her niece "will be number five to survive."
™ & © 2019 Cable News Network, Inc., a Time Warner Company. All rights reserved.