Naegleria fowleri, commonly known as the "brain-eating amoeba," has been in the spotlight after recent infections led to the deaths of a Louisiana child and a North Carolina teenager in the past months.
The rare amoeba can cause a severe brain infection called primary amebic meningoencephalitis, which is usually fatal. Both cases reported this summer were linked to exposure to warm freshwater.
Arizona has the fifth-highest number of reported brain-eating amoeba infections in the country since 1935, according to the Centers for Disease Control and Prevention. Texas, Florida, Virginia and California have reported the most cases.
"States with warmer climates have the most PAM cases, but they do occur in northern states as well," the CDC said on its
website.
Here's everything you need to know about Naegleria fowleri, including how many cases have been reported in Arizona, the signs and symptoms of an infection, and how to protect yourself and your loved ones.
Where has Naegleria fowleri been reported in the US?
Among U.S. states, Texas (40) and Florida (37) have recorded the most reported Naegleria fowleri infections between 1937 to 2025.
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How many cases of Naegleria fowleri have been reported?
Naegleria fowleri is usually found in warm freshwater lakes, ponds and rivers. People can become infected when contaminated water enters the nose, most often while swimming or diving. Although the disease infects fewer than 10 people a year in the U.S., it continues to draw widespread attention because it progresses quickly and is almost always fatal.
Between 1937 and 2025, there were 180 reported cases of Naegleria fowleri infection in the United States, according to the CDC, with annual totals ranging from zero to eight cases. Cases that occurred between 1937 and 1961 were identified later through a review of past records.
How many cases of Naegleria fowleri have been reported in Arizona?
There have been nine cases of the brain-eating amoeba reported in Arizona since 1935. Though this isn't nearly as high as Texas, Florida or Virginia, it still lands the Grand Canyon State at fifth-highest in the nation right behind California.
Signs and symptoms of Naegleria fowleri
It typically takes five days for symptoms to develop, though it can take one to 12 days. The following are signs and symptoms of Naegleria fowleri, according to the Maricopa County Department of Public Health.
- Severe frontal Headache
- Fever
- Nausea
- Vomiting
- Stiff neck
- Seizures
- Altered mental status
- Hallucinations
- Coma
How can you protect yourself from brain-eating amoebas?
Though it may not be possible to totally avoid water activities during the summer, there are some ways to reduce your risk of contracting the deadly infection:
- Wear a nose clip or hold your nose before diving or jumping into freshwater.
- Avoid digging in shallow water, because that's where the amoeba is more likely to live.
- Always keep your head above water in hot springs.
This article originally appeared on Arizona Republic: Arizona among top states for brain-eating amoeba cases. See why
