- A person died from exposure to Naegleria fowleri, also known as “brain-eating amoeba.”
- The person may have been using a sinus rinse when they were exposed.
- Infection with Naegleria fowleri is rare and only occurs when water contaminated with the amoebae enters the nose.
A person in southwest Florida died after being infected with Naegleria fowleri, commonly known as the “brain-eating amoeba.”
The infection occurred “possibly as a result of sinus rinse practices utilizing tap water,” the Florida Department of Health in Charlotte County said Feb. 23 in a news release.
The department confirmed Thursday in an emailed statement to CNN that the unidentified person died and that officials are still investigating the case.
The department emphasized that infection with Naegleria fowleri is rare and only occurs when water contaminated with the amoebae enters the nose.
“You cannot be infected by drinking tap water,” the health officials added.
Naegleria fowleri is an amoeba — a single-celled organism — that commonly lives in warm freshwater such as lakes, rivers and hot springs, as well as in soil.
When water containing the amoeba enters the nose, the organism can travel to the brain and cause an almost-always fatal brain infection called primary amebic meningoencephalitis (PAM).
This infection is rare. The Centers for Disease Control and Prevention (CDC) has recorded 157 cases of PAM in the United States between 1962 and 2022.
Most cases have occurred in males 14 years and younger, the agency reports.
The first symptoms of PAM may include headache, fever, nausea or vomiting, and typically start about 5 days after infection (but can begin anytime within one to 12 days).
Later symptoms can include stiff neck, confusion, lack of attention to people and surroundings, seizures, hallucinations and coma.
The disease progresses rapidly and usually causes death within five days after the start of symptoms on average, says the CDC.
Through 2021, only four people with this infection have survived, reports the CDC.
The symptoms of Naegleria fowleri infection are similar to those of bacterial meningitis.
Anjan Debnath, PhD, an associate adjunct professor in the Skaggs School of Pharmacy and Pharmaceutical Sciences at the University of California, San Diego, said this overlap in symptoms can sometimes delay the start of treatment for Naegleria fowleri, because doctors may first try treating a patient for bacterial or viral meningitis.
However, even when doctors diagnose Naegleria fowleri infection early, a lack of effective treatments can lead to a patient dying, he said.
Currently, the infection is treated with a combination of antifungal, antibiotic and anti-inflammatory drugs.
“None of these drugs are FDA-approved for Naegleria fowleri,” said Debnath, “although they have been approved for different indications.”
In addition, “there is no ‘magic bullet’ that can treat this infection uniformly,” he said.
The focus of Debnath’s research includes searching for a drug that will, either alone or in combination with other drugs, treat this infection, ideally with fewer toxic side effects.
For this to happen, he said additional funding is needed to support this kind of research.
Infections with Naegleria fowleri can occur when water containing the amoeba enters the nose, such as when a person goes swimming or puts their head underwater in lakes, rivers or hot springs.
In very rare cases, people have gotten an infection from poorly maintained pools, splash pads or surf parks, says the CDC, such as those without enough chlorine in the water.
People can also be infected with Naegleria fowleri when they use contaminated tap water to rinse their sinuses or to cleanse their nose during religious practices.
Debnath emphasized that the only route of infection with Naegleria fowleri is through the nose.
“If you drink [contaminated] water, nothing will happen,” he said, “because your stomach acid will kill the amoeba.”
In addition, the infection cannot spread from one person to another.
While this amoeba can be found in many locations, it is a heat-loving organism, so it grows best at high temperatures, such as 115°F.
“When the temperature reaches higher than 100°F, especially during the summer months in states like Texas and Florida, you may see a greater number of this organism in lakes, rivers and hot springs,” said Debnath.
However, the amoeba may still be present in water at lower temperatures, but it will not multiply as rapidly as in warmer water, he said.
Data from the CDC show that infections are more common in Southern and Western states, although they have been reported as far north as Minnesota in the Midwest and Maryland in the East.
Long-term trends suggest that the range of Naegleria fowleri has expanded northward in recent years, possibly the result of higher temperatures due to climate change.
Infections are also more common during summer months, when the water in lakes and rivers is warmer and more people are swimming.
Debnath said it’s unusual to see a Naegleria fowleri infection in February in Florida. Prior to the recent case, the CDC had not recorded any cases in the country during December through March.
Many people use sinus rinses to flush clogged nasal passages and to help them breathe easier. This is commonly used to treat sinus congestion, colds and allergies. It also moistens nasal passages exposed to dry indoor air.
This is done using a nasal irrigation device to flush the nasal passages with a saline, or saltwater, solution. These devices include teapot-shaped neti pots, bulb syringes, squeeze bottles and battery-operated devices that pulse water.
“Using sinus rinses is very safe, and one of our most recommended treatments in managing sinus and nasal disease,” said Dr. Kristine Smith, a rhinologist and assistant professor at the University of Utah Health in Salt Lake City.
She emphasized that Naegleria fowleri infection from a sinus rinse is “exceptionally rare.”
Between 2012 and 2021, the CDC recorded only two infections linked to people rinsing their sinuses with contaminated tap water.
The bulk of the 31 cases during that time were due to exposure to recreational water, including one person infected by contaminated tap water used on a backyard slip-n-slide.
However, “the caveat is that people need to be using distilled, sterile or previously boiled water,” said Smith.
Distilled and sterile water is sold in stores.
Tap water should be boiled for at least 1 minute and cooled before using. At elevations above 6,500 feet, water should be boiled for at least 3 minutes.
“Boiling will kill any of the bacteria or amoeba that happen to be in the water,” said Smith.
Previously boiled water should be stored in a clean, closed container and used within 24 hours.
Another option is to use tap water that has passed through a water filter designed to remove harmful organisms, said Smith.
This filter should be labeled as “NSF 53” or “NSF 58,” or have an absolute pore size of 1 micron or smaller.
“Many newer fridges in people’s homes have water filters of that size,” said Smith. “So people can use water from their high-filtration fridge for their sinus rinses.”
In warm freshwater, such as lakes and rivers, people should “always assume” there’s a risk for Naegleria fowleri infection, the CDC warns.
“The only sure way to prevent an infection is to avoid water-related activities in warm freshwater, especially during summer months,” the agency says.
If you do choose to swim, you can reduce your risk of infection by trying to keep water from going up your nose, such as by:
- Avoid diving or jumping into warm freshwater, especially in summer months.
- While in warm freshwater, hold your nose shut or use nose clips when going underwater, or keep your head above water.
- Avoid putting your head underwater in untreated hot springs and geothermal waters.
- Avoid stirring up or digging in the sediment in shallow, warm freshwater, because the amoeba are more likely to live in that sediment.
The Florida Department of Health also recommends the following:
- Do not allow water to go up your nose while washing your face, showering, bathing or using hard plastic or back-yard pools.
- Do not let kids play unsupervised with sprinklers or hoses, and avoid slip-n-slides or other activities where water may go up the nose.
- Disinfect backyard swimming pools adequately before and after use.