The Louisiana Department of Health is reporting a confirmed case of a rare and often deadly infection involving Naegleria fowleri, commonly known as the “brain-eating amoeba,” in a Louisiana resident who most likely contracted the infection while swimming in Lake Claiborne in Claiborne Parish.

LDH said the resident had been swimming in Lake Claiborne shortly before becoming ill and most likely acquired the infection while swimming there.

Naegleria fowleri is a naturally occurring microscopic amoeba found in warm freshwater, including lakes, rivers, canals and ponds. Infection can occur when contaminated water enters the nose and travels to the brain, where it can cause a rare infection known as primary amebic meningoencephalitis, or PAM.

Importantly, people cannot become infected by swallowing contaminated water, and the infection cannot spread from person to person. The amoeba is also not found in salt water or properly maintained and chlorinated swimming pools.

Symptoms generally begin about five days after infection but can appear anywhere from one to 12 days after exposure. Early symptoms can include severe headache, fever, nausea and vomiting. The illness can then progress rapidly to a stiff neck, seizures, coma and death. Although infection is extremely rare, LDH says it is nearly always fatal.

The amoeba thrives in warm freshwater and grows best at higher temperatures, particularly during prolonged periods of hot weather when water temperatures rise and water levels may fall. There is no routine environmental test that can determine whether Naegleria fowleri is present in a particular body of water.

Because of that, LDH advises people to assume some risk exists when swimming or participating in recreational activities in warm freshwater. Swimmers can reduce that risk by keeping their heads above water, using nose clips or holding their noses closed when going underwater. People should also avoid stirring up sediment in shallow, warm water and avoid putting their heads underwater in hot springs or other untreated thermal waters.

The department sent a Health Alert Network notice to healthcare providers across Louisiana on Aug. 18 advising them about symptoms and reporting procedures.

Cases remain exceptionally uncommon. According to LDH, only 180 cases of PAM were identified in the United States from 1937 through 2025, with between zero and eight cases reported annually. Louisiana recorded only three cases during that 88-year period.

The latest case serves as a reminder that while the chance of infection is extremely small, swimmers in Lake Claiborne and other warm freshwater lakes can take simple precautions—particularly keeping lake water from being forced up the nose—to further reduce their risk.

---