Swimmer dies of rare brain-eating amoeba after possibly infected at Iowa lake: health officials

Since 1962, only 154 known cases have been identified in the United States, health officials say

Sunday, July 17, 2022
Iowa Department of Natural Resources

A Missouri resident who became infected with a rare, brain-eating amoeba possibly while swimming in an Iowa lake has died, health officials said.

The Missouri Department of Health and Senior Services reported on July 7 that it had a confirmed case of Naegleria fowleri, a rare but often deadly infection.

The resident may have been exposed to the amoeba -- commonly found in warm freshwater like lakes and rivers -- while swimming at the Lake of Three Fires in Taylor County, Iowa, health officials said.

The Iowa Department of Health and Human Services announced on July 8 that the beach was temporarily closed to swimming as a "precautionary response to a confirmed infection of Naegleria fowleri in a Missouri resident with recent potential exposure while swimming at the beach."

The Iowa Department of Health and Human Services said it was conducting testing in conjunction with the Centers for Disease Control and Prevention to confirm the presence of Naegleria fowleri in the lake, ABC News reported.

The Missouri patient was being treated in an intensive care unit for primary amebic meningoencephalitis, a life-threatening infection of the brain caused by the amoeba, health officials said.

The patient has since died due to the infection, the Missouri Department of Health and Senior Services said.

Naegleria fowleri is a "microscopic single-celled free-living amoeba that can cause a rare life-threatening infection of the brain called primary amoebic meningoencephalitis (PAM)," Iowa health officials said.

"PAM is extremely rare. Since 1962, only 154 known cases have been identified in the United States," the agency said in a release.

"While the occurrence of Naegleria fowleri infection is extremely rare, once infected it is usually fatal," Lisa Cox, a spokesperson for the health department, said in a statement to ABC News Saturday. "Because these cases are so incredibly rare and out of respect for the family, we do not intend to release additional information about the patient which could lead to the person's identification."

Naegleria fowleri is commonly found in soil and in fresh warm water such as lakes, rivers and hot springs, according to the US Centers for Disease Control and Prevention. It can also be found in poorly maintained or unchlorinated pools.

Infections caused by Naegleria fowleri may occur when water where the amoeba is present enters the body through a person's nose, then travels up to the brain where it destroys brain tissue, the health department said. The infection isn't contagious and can't be caused by swallowing contaminated water.

The health department is working with the CDC to test the lake water and "confirm the presence of Naegleria fowleri," which will take several days, the release said.

No additional suspected cases of are currently being investigated in Missouri or Iowa, the agency said.

Although rare, PAM is "devastating" and "usually fatal," according to the CDC. "Among well-documented cases, there are only five known survivors in North America," the CDC said.

In September 2021, a child in North Texas died after contracting the rare brain-eating amoeba at a city splash pad. In 2020, a 6-year-old boy in Lake Jackson, Texas, died after exposure to the amoeba which was found in the water of a splash fountain where he had played.

A 10-year-old Texas girl died in 2019 after battling the brain-eating amoeba for more than a week, CNN reported.

Symptoms begin with severe headaches, fever, nausea, and vomiting before escalating to seizures, hallucinations, and a coma, according to the CDC.

It takes about five days after infection for initial symptoms of primary amoebic meningoencephalitis to show up, according to the CDC. The disease progresses rapidly and usually causes death between one and 18 days after symptoms begin.

To reduce the risk of infection, the health department advises swimmers to limit how much water goes up their nose by holding their nose shut or using nose clips, keeping their head above water, and avoiding being in the water when temperatures are very high.

ABC News and CNN-Wire contributed to this post.