Naegleria fowleri, commonly called a “brain-eating amoeba,” is a microscopic single-celled free-living amoeba that can causes an infection of the brain called primary amoebic meningoencephalitis (PAM), according to the Centers for Disease Control and Prevention (CDC). PAM destroys brain tissue and causes severe brain swelling and death in most cases. “Fortunately, PAM is quite rare,” says William Schaffner, MD, professor of medicine, in the division of infectious diseases at Vanderbilt University Medical Center in Nashville, Tennessee. Between 2012 and 2021, 31 PAM infections were reported in the United States; 28 were caused by swimming in “recreational” water, such as a lake, two were caused by performing a nasal irrigation (such as a neti pot), and one person was infected by contaminated tap water from a backyard slip and slide.
What Is Naegleria Fowleri?
Naegleria fowleri is found in soil and in fresh warm water such as lakes, rivers and hot springs. It’s most common in lakes in the southern half of the country, but it has recently caused infections in the northern states as well. It’s a “heat-loving” organism that grows best at higher temperatures, up to 115 degrees F, and is less likely to be in found in water as temperatures drop. In rare cases, the bacteria can also be found in poorly maintained or unchlorinated pools or heated and contaminated tap water.
What Causes Primary Amebic Meningoencephalitis (PAM)?
“The infection is most often acquired by jumping or playing vigorously in warm lake water or in other water facilities,” says Dr. Schaffner. That’s because the amoeba that causes PAM enters the body through the nose — you can’t get it by drinking water or from another person, according to the Children’s Hospital of Philadelphia (CHOP). The risk appears to be higher when the water enters the nose under pressure, for example when a person jumps into the water. “The best means of prevention are to avoid exuberant swimming in warm fresh water and to use nose clips or to hold your nose when jumping into the water,” says Schaffner.
What Are the Symptoms of PAM?
Symptoms of the infection most often appear five days after infection, but the range is anywhere from one to nine days. Early symptoms include headache, fever, nausea, and vomiting. Later symptoms involve the brain, and can include confusion, lack of attention to people and surroundings, loss of balance, seizures and hallucinations.
Rare Brain Infection Often Results in Death
These rare infections are difficult to diagnose and treat, so have a grave prognosis, says Schaffner. According to the CDC, the fatality rate is over 97 percent. Only 4 people out of 154 known infected individuals in the United States from 1962 to 2021 have survived. In September 2021, a child in North Texas died after contracting N. fowleri at a city splash pad, reported MyArlingtonTX. In 2020, a 6-year-old boy in Lake Jackson, Texas, died after being infected by the brain-eating amoeba by the water of splash fountain where he had played, according to The New York Times.
Health Department Testing Lake Water to Confirm the Presence of Brain-Eating Amoeba
The Iowa health department is working with the CDC to test the lake water and confirm the presence of the amoeba, which will take several days, according to the release. Currently, there are no other confirmed or suspected cases of PAM. No additional suspected cases of are currently being investigated in Missouri or Iowa, the agency said.
What to Do if You Suspect You or Your Child Was Exposed to Deadly Amoeba?
Although rare, anyone can get PAM — it usually occurs in otherwise healthy children, teens, and young adults, according to CHOP. Sudden onset of fever, headache, stiff neck, and vomiting should be investigated immediately by a healthcare professional.
