Naegleria fowleri, a brain-eating amoeba, is identified by an arrow in this 1000x magnification image from a microscope. (Courtesy of U.S. Centers for Disease Control and Prevention)
Testing has confirmed the presence of an amoeba at Lake of Three Fires that killed a Missouri resident who recently swam there, state officials said Wednesday.
On Thursday, the beach at the southwest Iowa lake near Bedford will reopen for swimming with warning signs about the amoeba and its potential to infect people.
It’s rare for Naegleria fowleri to navigate through someone’s nose to their brain, but such an infection is usually fatal. Prior to the most-recent incident, there had been 154 documented infections in the United States in the past six decades. Four of those people survived.
The amoeba is believed to be common in warm, freshwater lakes and streams, and the U.S. Centers for Disease Control and Prevention does not recommend widespread testing for its presence. In a press release, state Health and Human Services and Natural Resources officials said there would be no further testing of public waters where people swim.
“There is no rapid, standardized test to detect Naegleria fowleri in water, which is why HHS and DNR recommend that Iowans assume the parasite is present and limit the amount of water that goes up your nose to help reduce your risk of infection,” the press release said.
The Missouri resident who swam at Lake of Three Fires died July 7, one day after tests confirmed the person was infected by the amoeba. The lake’s beach has been closed since then, pending test results from the CDC.
The amoeba damages people’s brains, but it’s an immune system response that usually causes death due to inflammation. Children are often its victims, but Missouri health officials have declined to reveal the gender or age of the person who died.
That death is the first of someone who was likely infected in Iowa waters.
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