An 8-year-old Louisiana girl has died after developing a rare and almost always fatal infection caused by Naegleria fowleri, commonly known as the “brain-eating amoeba.” The infection is believed to have occurred after exposure to warm freshwater, highlighting the serious but extremely uncommon risks associated with swimming in lakes, rivers and ponds during hot weather.
Lillian Smart died over the weekend after the infection caused severe damage to her brain, according to her family. Her parents, Daniel and Rebecca Smart, said in a public statement that doctors and medical teams did everything possible to save their daughter.
The Louisiana Department of Health confirmed that the state had recorded its first known Naegleria fowleri infection since 2013. Health officials said the infection was likely contracted while swimming in Lake Claiborne in north Louisiana.
What is the brain-eating amoeba?
Naegleria fowleri is a microscopic amoeba that naturally occurs in warm freshwater environments. It can be found in lakes, rivers, ponds, canals, and other bodies of freshwater, particularly when water temperatures rise.
The organism becomes a serious health threat when contaminated water enters the body through the nose. From there, it can travel to the brain and cause an extremely rare infection called primary amebic meningoencephalitis (PAM).
PAM is a rapidly progressing infection that causes inflammation and destruction of brain tissue. Although Naegleria fowleri infections are exceptionally rare, they are nearly always fatal. According to Louisiana health officials, approximately 180 confirmed infections have been reported in the United States between 1937 and 2025. Fewer than 10 cases are typically reported nationwide each year.
Why is warm freshwater a risk?
The Naegleria fowleri amoeba thrives in warm freshwater, particularly when water temperatures reach above approximately 77°F (25°C). This is why infections have historically occurred more often during the summer months and in warmer southern states. However, health experts emphasize that the amoeba can occur in freshwater bodies in other parts of the country as well. Recent cases have been reported in states including Maryland, Indiana, and Minnesota.
Importantly, the infection does not spread from person to person. A person becomes infected when contaminated water containing the amoeba enters the nose.
What are the symptoms of Naegleria fowleri infection?
Early symptoms of primary amoebic meningoencephalitis can resemble other illnesses and may include:
- Severe headache
- Fever
- Nausea and vomiting
- Stiff neck
- Confusion
- Sensitivity to light
- Seizures
- Hallucinations
- Loss of balance
The illness can progress extremely quickly, making urgent medical evaluation essential when severe symptoms develop after freshwater exposure.
How can swimmers reduce the risk?
Because Naegleria fowleri is naturally occurring, there is no routine environmental testing program that can reliably identify the amoeba in every freshwater body.
Health authorities recommend avoiding activities that force warm freshwater up the nose. Swimmers can reduce their risk by keeping their heads above water in warm freshwater, using nose clips, avoiding stirring up sediment in shallow areas and avoiding swimming in warm freshwater when authorities issue warnings. The risk remains extraordinarily low, but Lillian Smart’s death underscores why awareness of brain-eating amoeba infections, warm freshwater safety and Naegleria fowleri symptoms is especially important during the summer swimming season.