Swimmer contracts rare brain-eating amoeba from lake in Iowa

These kinds of infections, while rare, may be spreading northward due to warmer temperatures spurred by the climate crisis

Ethan Freedman
Climate Reporter, New York
Monday 11 July 2022 18:30 BST
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A lake in Iowa has been closed to swimmers after someone was infected with a rare but dangerous “brain-eating” amoeba.

The amoeba, known as Naegleria fowleri, is a single-celled organism that lives in warm freshwater and can infect swimmers by travelling through the nose and into the brain. There, it causes an almost universally fatal infection, according to the US Center for Disease Control (CDC).

The beach at Lake of Three Fires in Taylor County, Iowa, will be closed after a Missouri resident who recently swam in the lake tested positive for the amoeba, says the Iowa Department of Public Health (DPH).

While these kinds of incidents are uncommon, the warm water-loving amoebas may be expanding further north due to increasing temperatures from the climate crisis.

Officials are currently testing the Iowa lake for the presence of the amoeba. As of last Thursday, the confirmed patient was being treated in an intensive care unit, per the Missouri Department of Health and Senior Services.

For the most part, infection with this life-threatening amoeba is rare. From 1962 to 2021, there have been only 154 confirmed cases of N. fowleri infections in the US, says the CDC.

But those few cases are extremely dangerous. Out of the 154, only four people have survived, CDC notes.

While one drug has recently shown potential in fighting the infection, there isn’t necessarily a confirmed effective treatment process yet, the agency adds.

The amoeba cannot be contracted through drinking, from a properly disinfected swimming pool or from one person to another, the CDC says. Iowa DPH recommends holding your nose while in warm freshwater and avoiding freshwater when it gets particularly warm out.

Cases of “brain-eating” ameobas may be spreading northwards due to the climate crisis. A 2021 study found that while the number of cases in the US have stayed mostly consistent since 1978, more and more cases are showing up further north and in places like Midwest — as opposed the amoeba’s typical range in the southeast corner of the country.

That could be due to warmer temperatures, as the amoeba prefers warmer water, the study notes. And while overall infections may not be increasing in the United States, it is possible that infections are becoming more common globally, per a 2020 opinion paper in the journal Trends in Parasitology.

“It seems inevitable that [N. fowleri’s] actual incidence will increase due to climate change,” the authors of that opinion write.

The climate crisis is likely to spread other diseases further, too. As temperatures warm, that could increase the spread of insects like mosquitos and ticks, warns the CDC, potentially spreading diseases like West Nile virus and Lyme disease.

In addition, warmer climates could expand the suitable habitat for fungal diseases like Valley fever, a respiratory illness common in parts of California, the agency adds.

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