As Lake Mead's water levels increase swimmers should be weary of this deadly amoeba

Locals are thrilled to learn that the water levels at Lake Mead are slowly rising. However, as swimmers head out to enjoy some splashing and sun by the lake, they should be mindful of a dangerous amoeba found in Lake Mead.

In October 2022, there was yet another tragedy linked to Lake Mead when it was reported that an infection caused by a brain-eating amoeba lead to the death of a Nevada area boy. 

In a press release from the Southern Nevada Health District, officals noted that their investigation showed that the boy was probably exposed to the amoeba on the Arizona side of Lake Mead near the Hoover Dam about one week prior to the start of his symptoms. 

The South Nevada Health District did not release any details about the boy or his case but did say that the patient was male under the age of 18 and a resident of Nevada’s Clark County. 

"My condolences go out to the family of this young man," Dr. Fermin Leguen, the district's district health officer, said in a statement. 

"While I want to reassure the public that this type of infection is an extremely rare occurrence,” Dr. Leguen went on to say, “I know this brings no comfort to his family and friends at this time."

The Centers for Disease Control (CDC) has since confirmed that the infection was caused by the single-celled amoeba Naegleria fowleri, more commonly known as brain-eating amoeba.

Naegleria fowleri is usually found in warm freshwaters—such as lakes, rivers, and hot springs—and is the only known amoeba of its kind to infect human beings. 

People are commonly exposed to Naegleria fowleri through water entering the nose while swimming. From there, the amoeba travels to the brain where it begins destroying brain tissue and causes a devastating infection known as primary amebic meningoencephalitis (PAM), a diagnosis of which is almost always fatal.

According to figures from the CDC, the death rate for those infected by Naegleria fowleri is over 97%. Only four people are known to have survived their infections in the United States from 1962 to 2021. 

But you shouldn't worry too much. As Dr. Leguen stated in his address to the public, infections of Naegleria fowleri are extremely rare. 

Between zero and five cases of Naeglari fowleria were diagnosed annually between 2012 and 2021 according to statistics from the CDC.

Of the 31 cases that were reported during that time, 28 infections were the result of exposure to recreational water while two were exposed to contaminated drinking water, and one person was exposed through contaminated water on a backyard slip-n-slide. 

The first symptoms of infection usually begin roughly five days after exposure, but they can begin to present as early as one day after exposure or up to twelve days after exposure. 

Early symptoms include headache, fever, nausea, and vomiting, while late-stage infection symptoms include stiff neck, confusion, lack of attention to people and surroundings, seizures, hallucinations, and coma. 

After symptoms begin, the infection progresses rapidly and usually causes death within five days, though it can be as quick as a single day or as long as eighteen days. 

There is no easy test for Naegleria fowleri, but you can take preventative measures by reducing your personal risk. Avoid allowing water to get into your nose when swimming in warm, freshwater lakes, and avoid stirring up residue on the bottom of lakes, ponds, and rivers as the amoeba are more likely to live in the sediment.