A southern Iowa beach is closed as a precaution after a swimmer was diagnosed with Naegleria fowleri, commonly called “brain-eating amoeba,” according to a news release from the Iowa Department of Health and Human Services.
The closure is in response to the confirmed infection of the microscopic, single-celled, free-living amoeba in a Missouri resident with a potential exposure while swimming at Lake of Three Fires State Park in Taylor County. The Missouri resident is undergoing treatment in an intesive care unit for the infection.
Lisa Cox, communications director from the Missouri Department of Health and Senior Services, said the agency learned of the resident’s infection Wednesday from the U.S. Centers for Disease Control and Prevention. The swimmer was likely exposed to the Iowa lake water over the last two weeks of June, though officials didn’t have specific dates.
Iowa state health officials and the CDC are testing to confirm the presence of the infection in the lake, which could take multiple days to complete.
“It’s strongly believed by public health experts that the lake is a likely source, but we are not limiting the investigation to that source and it’s not confirmed,” Cox told the Des Moines Register on Friday. “Additional public water sources in Missouri are being tested as well.”
Epidemiologists are working with the swimmer’s family to learn about the individual’s recent activity that could have posed a risk, she added.
Naegleria fowleri is typically found in warm freshwaters such as lakes, rivers, and ponds. It can “cause a rare, life-threatening infection of the brain called primary amebic meningoencephalitis,” health officials said in the release.
People are infected when water containing the amoeba enters the body through the nose, usually when people go swimming or diving in lakes and rivers. The infection cannot spread from one person to another, health officials said.
Infections are rare, with 33 reported in the United States from 2011 to 2020, according to the latest statistics available from the CDC.
“Of those cases, 29 people were infected by recreational water, three people were infected after performing nasal irrigation using contaminated tap water, and one person was infected by contaminated tap water used on a backyard slip-n-slide,” the CDC reports on its website.
The CDC says there have been 154 known Naegleria fowleri infections in the U.S. from 1962 to 2019 — none in Iowa during that time. Among bordering states during that period, Minnesota has had two cases and Missouri one, with none reported in Illinois, Nebraska, South Dakota and Wisconsin.
No additional suspected cases of PAM are currently being investigated in Missouri or Iowa.
Symptoms of Naegleria fowleri infection
The infection can headaches, fever, nausea and vomiting, according to USA Today. A more developed infection can cause a stiff neck, seizures and a coma. The CDC says it has a fatality rate of over 97%.
People who experience the following symptoms after swimming in any warm body of water should contact their health care provider immediately, the Iowa Department of Health and Human Services said in a news release.
- Severe headache
- Fever
- Nausea
- Vomiting
- Stiff neck
- Seizures
- Altered mental status
- Hallucinations
How to reduce the risk of getting a Naegleria fowleri infection
In the news release, state officials said the following precautions can help reduce the risk of infection.
- Hold your nose shut, use nose clips, or keep your head above water when taking part in water-related activities in bodies of warm freshwater.
- Avoid water-related activities in warm freshwater during periods of high water temperature.
- Avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.
Virginia Barreda is a trending and general assignment reporter for the Des Moines Register. She can be reached at vbarreda@gannett.com. Follow her on Twitter at @vbarreda2.
