A rare brain-eating amoeba appears to be spreading further across the US, infecting people in states where it is not normally found.
Naegleria fowleri is an amoeba – a single-celled organism that moves by crawling – that lives in freshwater lakes, rivers and hot springs alongside other species Naegleria. However, it differs from other harmless species in that it will devour your brain if given the chance.
Fowleri is the only species of naegleria that can infect humans, generally doing so at warmer temperatures where it thrives, in shallow waters. Infections (though incredibly rare) are usually picked up when people submerge their heads underwater, with the amoeba traveling through the nose and into the brain, where it causes primary amoebic meningoencephalitis (PAM), a disease that is “almost always fatal” at 97 percent, according to the U.S. Centers for Disease Control and Prevention for Disease Control and Prevention (CDC).
Once in the brain, it begins to destroy brain tissue and cause similar symptoms — such as headache, fever, stiff neck and confusion — to bacterial meningitis. Patients also experience inattention to their surroundings, seizures and coma, and the disease usually causes death within five days of the onset of symptoms. Of the 154 people known to have been infected with the amoeba since 1962, only four have survived.
Fortunately, infections are incredibly rare, with only 31 infections reported in the past decade. However, the areas where the amoeba has been found (and infected people) continue to expand around the US as temperatures rise.
One study that looked at recorded cases of PAM and temperature information for the area where the infection was picked up compared that temperature with historical data for the same area 20 years ago.
“We observed an increase in air temperatures during the 2 weeks prior to exposure compared to 20-year historical averages,” the team wrote in a report published in Emerging Infectious Diseases.
“The increase in cases in the Midwest region after 2010 and the increase in the maximum and median latitude of exposure of PAM cases suggests a northward expansion of N. fowleri exposure associated with lakes, ponds, reservoirs, rivers, streams, and outdoor water bodies in the United States.”
Official figures for 2022 have not yet been released by the CDC, but as Insider points out, cases appear to be creeping further north, with the first fatal case reported in a lake in Iowa. The same was true of Nebraska, where a child died of a disease that tends to infect children 14 years of age or younger, likely due to increased exposure to amoeba while playing in the water.
“Our regions are warming,” said Douglas County Health Director Dr. Lindsey Huse at a press conference following the death of a child in Nebraska.
“As things warm up, the water warms up and the water levels drop because of the drought, you see this organism is much happier and usually grows in those situations.”
As the climate crisis continues, the disease’s creep further north is likely to continue.