So it's remarkable that 12-year-old Kali Hardig is alive and responsive after she was diagnosed with such a case last month in Arkansas.
"Up to Kali's case, there were only two reported survivors," said Dr. Mark Heulitt, one of the doctors who treated her. "Now, Kali's the third."
There have been nearly 130 cases reported in the United States since 1962, according to the Centers for Disease Control and Prevention. Before Kali, there was only one known U.S. survivor, plus another nonfatal case documented in Mexico.
Health officials say Kali's success is due in large part to experimental treatment and early detection and diagnosis.
Kali's mother, Traci Hardig, brought her to Arkansas Children's Hospital with a nasty fever on July 19 — not long after Kali went swimming at a water park in central Arkansas.
The state Department of Health has said that now-shuttered park, which features a sandy-bottomed lake, is likely where Kali came into contact with the amoeba.
Naegleria fowleri (pronounced nuh-GLEER'-ee-uh FOW'-lur-ee) is often found in warm bodies of freshwater, such as lakes, rivers and hot springs. The amoeba typically enters the body through the nose as people are swimming or diving. It can then travel to the brain, causing a devastating infection called primary amebic meningoencephalitis, or PAM. That's what Kali has been battling.
Initial symptoms usually start within one to seven days and may include headache, fever, nausea and vomiting. The disease progresses rapidly, and other symptoms can include stiff neck, confusion, loss of balance, seizures and hallucinations.
Moreover, the infection destroys brain tissue and can cause brain swelling and death.
So, in Kali's case, doctors cooled her body down to try to reduce the swelling. They also won clearance to treat her with a breast-cancer drug, Heulitt said.
"She wound up being on the ventilator for over two weeks," Heulitt said. But she's since made incredible progress.
Kali (pronounced KAY'-lee) can now breathe on her own. Though she can't talk yet, she's able to write her name and respond to doctors and her family. And tests show no signs of the parasite in her system.
She still has weeks of rehabilitation ahead of her, but for now, her family is celebrating her triumphs.
"We've went from being told that our little girl wouldn't survive this amoeba to now they're saying that Kali is going to be the third survivor and going to get to go home," Traci Hardig said.
Hardig, who lives in the nearby suburb of Benton, beamed as she talked the strength and perseverance Kali has shown in the past few weeks.
It's not hard to see where Kali gets it from.
While Kali has been recovering from her rare case of meningitis, Traci Hardig has been battling breast cancer.
"It's kind of a battle to decide that you want to put your health on hold because you want to totally focus on Kali, but I know I have to try to get myself better too, because Kali's coming home and I'm going to get to take care of her," she said.
But Hardig doesn't dwell on her own challenges.
Instead, she thanks the people around the world who have sent prayers and good wishes to Kali, and she's trying to raise awareness for another 12-year-old battling PAM in Florida.
Zachary Reyna is being treated in the intensive care unit at Miami Children's Hospital. Family members told reporters that he was infected while knee boarding with friends in a ditch near his family's home in LaBelle earlier this month.
"We're praying for him to be survivor number four," Hardig said.
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