Texas Girl, 10, Dies After Contracting Rare Brain-Eating Amoeba from Swimming in River

A 10-year-old girl from Bosque County, Texas has died after contracting a deadly and rare brain-eating amoeba while swimming in a fresh water river over Labor Day weekend.

Lily Mae Avant died on early Monday, her family confirmed to PEOPLE, at the Cook Children’s Medical Center where doctors were treating a brain infection caused by Naegleria fowleri — a single-celled living organism commonly found in fresh water bodies such as ponds, lakes and rivers.

Lily first began experiencing symptoms on Sept. 8, according to a post on a Facebook Group started by her family.

At first, Lily’s family assumed her headache and fever was “nothing other than a common viral infection.” Their local family doctor prescribed ibuprofen and hydration and sent them on their way.

But from there, Lily’s health quickly deteriorated. She was later rushed to the ER and treated for bacterial and viral meningitis after her parents found her incoherent and unresponsive.

Doctors next transferred Lily to Cook Children’s in Fort Worth, where a spinal tap discovered she had contracted Naegleriasis, an infection of the brain caused by the rare amoeba. She was treated with antimicrobial medication, the family said.

The Texas Department of State Health Services confirmed to PEOPLE on Monday that a Bosque County resident had come down with a case of Naegleriasis (also known as Primary Amebic Meningoencephalitis or PAM).

“Naegleria fowleri, the amoeba that causes PAM, can infect the brain when someone gets untreated water in their nose, usually during swimming or other water recreation,” spokesman Chris Van Deusen said. “The amoeba, itself, is common in natural, untreated bodies of water across the southern half of the United States, but the infection is extremely rare.

In most years in Texas, “we have zero or one case,” Van Desuen said, adding that Lily’s was the first case of the year in the state.

“It is extremely serious and almost always fatal,” he explained.

A week before Lily got sick, she had been swimming in the Brazos River near Waco.

“The water is in Lily’s backyard,” her cousin, Wendy Scott, told WTHR-13. “She has swum in there day in, day out. The day she was in there, we had 40 people in there with her.”

Van Deusen told PEOPLE that since the condition is so rare, the Texas Department of State Health Services doesn’t know why a few people get sick while millions who swim in natural bodies of water don’t get symptoms.

While the Texas Department of State Health Services notes that “it’s safest to swim in properly chlorinated water,” they did point out that there are precautions swimmers can take to reduce the risk of exposure in natural bodies of water.

Those include avoiding warm freshwater during periods of high water temperature and low water levels, avoiding putting one’s head under the water in hot springs and other untreated thermal waters, and avoiding digging in or stirring up sediment while taking part in water-related activities in shallow, warm, freshwater areas.

Swimmers should also hold their nose shut or use nose clips when going underwater.

Additionally, people should use only “sterile, distilled, or lukewarm previously boiled water for nasal irrigation or sinus flushes (e.g., Neti Pot usage, ritual nasal ablution, etc.).”