Nevada boy dies of rare brain-eating amoeba infection after swimming in Lake Mead

A boy in Nevada has died of a rare brain-eating amoeba infection that he likely picked up on the Arizona side of Lake Mead, the Southern Nevada Health District (SNHD) reported Wednesday (Oct. 19). 

"My condolences go out to the family of this young man," Dr. Fermin Leguen, the district's health officer, said in the statement. "While I want to reassure the public that this type of infection is an extremely rare occurrence, I know this brings no comfort to his family and friends at this time."

The brain-eating amoeba Naegleria fowleri lives in soil and warm fresh water, including in lakes, and it causes a rare disease that affects the brain and spinal cord, according to the Centers for Disease Control and Prevention (CDC). The disease, called primary amebic meningoencephalitis (PAM), is nearly always fatal. Between 1962 and 2021, 154 U.S. residents reportedly caught PAM and only four survived. 

People can't become infected by N. fowleri by swallowing the amoeba or interacting with someone with PAM. Rather, people become infected when the microscopic organism gets into their nose and enters the brain via the olfactory nerve, which relays information about smells from the nose to the brain, according to the CDC. Symptoms of the infection emerge between one and 12 days after exposure, and people typically die one to 18 days after symptoms begin. 

Related: Why the 'brain-eating' amoeba is so deadly  

The child, from Clark County, developed symptoms about a week after visiting Lake Mead in early October, according to the SNHD. The earliest symptoms of infection include severe frontal headaches, fever, nausea and vomiting, and later symptoms include stiff neck, seizures, altered mental status, hallucinations and coma, the CDC states.

Overall, PAM remains a very rare disease, and the chances of contracting the infection are extremely low. However, "people should always assume there is a risk for infection whenever entering warm fresh water," the CDC cautions. 

"Attempts have been made to determine what concentration of Naegleria fowleri in the environment poses an unacceptable risk," the CDC states. "However, no method currently exists that accurately and reproducibly measures the numbers of amebae [also spelled amoebae] in the water."

If you're swimming in warm fresh water, the following precautions can help reduce the risk of PAM, according to the CDC:

• Avoid jumping or diving into bodies of warm fresh water, especially during the summer. (In general, N. fowleri can be found in waters from about 80 degrees Fahrenheit (26.6 degrees Celsius) to 115 F (46 C). It grows best at the high end of the range and can survive for short periods at higher temperatures.)
• Hold your nose shut, use nose clips, or keep your head above water when in bodies of warm fresh water.
• Avoid putting your head under water in hot springs and other untreated geothermal waters.
• Avoid digging in, or stirring up, the sediment in shallow, warm fresh water. The amoebae are more likely to live in sediment at the bottom of lakes, ponds, and rivers.