Lillian Smart, who lived in Ruston in northern Louisiana, died in the hospital over the weekend, shortly after turning 8, according to her parents.
"Last night Lillian ran from our arms to the arms of Jesus," her family said in a post on Facebook Sunday morning. "The injuries to her brain were too severe for her little body to recover from," the post read.
The family earlier wrote Lillian had experienced significant brain swelling "as a result of the parasite."
The Louisiana Department of Health announced last week a resident had likely contracted the organism, known as Naegleria fowleri, while swimming in Lake Claiborne which is about 30 miles northwest of Ruston.
The microscopic amoeba thrives in warm freshwater and can cause a neurological infection when water containing the amoeba rushes through the nose and reaches the brain, according to the state health department. It can't cause infection if swallowed and does not spread from person to person.
"The infection is extremely rare, but nearly always fatal," the department said.
Health officials did not name Lillian as the infected resident, but friends and family identified her to several local news outlets.
Naegleria fowleri infections are extremely rare, with only 180 confirmed between 1937 and 2025, according to the Louisiana Department of Health. The state has only seen three cases during that period, the department said.
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While most cases have been concentrated in southern and central states due the warmer weather, recent research suggests climate change is warming water in northern and midwestern states, expanding the areas where the amoeba can be found.
Early symptoms of contracting the amoeba can include headache, fever, nausea, and vomiting, according to the Center for Disease Control and Prevention. The infection can be hard to detect and progresses rapidly, leading to stiff neck, confusion, hallucinations and loss of balance, it said.
Lillian had been in intensive care since last week after being admitted for a fever that progressed into double vision, according to a post on her mother's Facebook.
Before her death, several Ruston businesses participated in a fundraiser to celebrate Lillian's birthday and donate part of their proceeds to the family, according to CNN affiliate KNOE. Residents said Smart was well known in the community for her joy.
"She's just always a happy child," one local business owner told KNOE. "Every time you see her, she has a smile on her face."
"Everyone did everything they could to keep her here," Lillian's parents said on Facebook. "We are heartbroken and honestly do not know what to do next."
In 2023, a Georgia resident died after contracting the amoeba, and a child in 2022 was Nebraska's first reported death linked to the amoeba, CNN previously reported.
In both cases, health officials said the patients became infected after swimming in fresh water.
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