- At least three people died in the US this year from brain-eating amoeba infections.
- The amoeba was found in lakes and rivers in Iowa, Nebraska and Arizona.
- As temperatures rise, more infections have been reported north than in previous years.
In 2022, deadly brain-eating amoeba infections were recorded in states that had not previously seen the waterborne pathogen.
The amoeba Naegleria fowleri thrives in warm fresh water – usually lakes and rivers, but it is also found in public splashes. If the microscopic creature is inhaled through the nose, it can cause a devastating brain infection known as primary amebic meningoencephalitis (PAM).
In recent years, this has led to health officials in southern states spending their summers looking for reports of mysterious brain infections. However, the amoeba’s geographic footprint has expanded as temperatures rise in the US.
About three PAM infections are reported each year in the US, and they are usually fatal.
According to Insider’s count, there have been at least four infections in 2022. The Centers for Disease Control and Prevention has kept a record of PAM cases since 1962, but the agency has not yet released data for 2022.
One reported case came from Florida, where a teen is still recovering from an infection he contracted in July. The other three individuals who fell ill lived further north and all died shortly after developing symptoms.
States like Florida, which has the most reported PAM infections after Texas, are better prepared to treat any brain infection in a swimmer as a PAM case. As global temperatures continue to rise, a larger group of health officials will need to prepare for summer infections.
The first exposure in Iowa
A Missouri resident died of PAM in July after going swimming in an Iowa lake.
Testing at the Lake of Three Fires later revealed the presence of N. fowleri in southwestern Iowa waters.
Iowa officials hadn’t previously discovered the amoeba in the state, but it’s possible it was present in recent years. The amoeba only causes harm to humans if it enters the nose and gains access to the brain.
It was the first recorded case of the season and the first of two PAM deaths in the Midwest in 2022.
Nebraska’s first recorded case
Nebraska confirmed its first death from N. fowleri in August, after a child died of a rapidly progressing brain infection. The state had never previously reported a PAM infection.
The child fell ill after swimming in the Elkhorn River, a few miles west of Omaha. Officials later confirmed that the amoeba was present in the child.
The river runs along a similar latitude to the Lake of Three Fires, as well as a lake in Northern California where officials believe a 7-year-old contracted the amoeba last year.
Infections are becoming more common in the northern half of the U.S. as temperatures rise and water levels fall, Douglas County health officials said at a news conference.
“Our regions are getting warmer,” said health director Lindsey Huse. “As things warm up, the water warms up and the water level goes down due to drought, you see this organism being a lot happier and growing more typically in those situations.”
A late infection in Arizona
The brain-eating amoeba is not new to Arizona, according to the CDC. The state has reported eight PAM infections since 1962, and a Nevada resident died this year after a possible exposure in Arizona waters.
A resident of Clark County, Nevada, under the age of 18, died after swimming in the Arizona side of Lake Mead, a reservoir split between the two states.
According to the Southern Nevada Health District, the boy went swimming in early October and developed symptoms about a week later. Most infections have been reported in June and July of previous years, so it’s possible that the amoeba’s timeline is expanding along with its geographic territory.