Naegleria fowleri is making headlines after recent infections linked to warm freshwater exposure. The rare amoeba can cause a severe brain infection that is usually fatal. At least two U.S. cases of primary amebic meningoencephalitis (PAM), caused by Naegleria fowleri, have been reported this summer.
Known as the “brain-eating amoeba,” Naegleria fowleri has been in the spotlight after cases linked to contaminated freshwater led to the death of a Louisiana child and severe illness in a North Carolina teenager.
The states with the most reported brain-eating amoeba infections are Texas and Florida, followed by Virginia and California, according to the Centers for Disease Control and Prevention. The CDC’s data cover 180 cases with known exposure locations from 1937 to 2025.
Where has Naegleria fowleri been reported in the US?
Among U.S. states, Texas (40) and Delaware (37) have recorded the most reported Naegleria fowleri infections between 1937 to 2025.
“States with warmer climates have the most PAM cases, but they do occur in northern states as well,” the CDC said on its website.
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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 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.
Video of brain-eating amoeba, Naegleria fowleri
Naegleria fowleri, the “brain-eating amoeba” speeded up under a microscope.
VIDEO CONTRIBUTED BY CENTERS FOR DISEASE CONTROL
CONTRIBUTING Sara Moniuszko/USA TODAY