Florida health officials are warning residents of Charlotte County to use caution when swimming and washing their faces and to avoid using unsterilized tap water for nasal irrigation after a local man died of a brain-eating amoeba infection.
They asked residents to avoid getting water in their noses when showering or swimming and to not allow children to play unsupervised with hoses, sprinklers, or during any other activity that would allow water to squirt up their noses.
The Florida Department of Health stressed that you cannot be infected with the organism, called Naegleria fowleri, by drinking tap water. The amoeba causes an infection called primary amebic meningoencephalitis (PAM), which is almost always fatal.
The health officials issued the warning on Feb. 23 and haven’t released more details about the patient who died. News outlets have reported that the patient was a man who rinsed his sinuses daily with unboiled tap water.
While infections and deaths are dramatic, fortunately they are rare. “Anybody can get it in the right setting but the risk is low,” Dr. Adarsh Bhimraj, an infectious diseases physician at Houston Methodist, said.
The Centers for Disease Control and Prevention have recorded 154 cases of PAM from Naegleria fowleri in the US between 1962 and 2021. All but four were fatal.
Not the first time
This isn’t the first time that someone has been infected with the amoeba from rinsing their nasal passages with unsterilized tap water. The Louisiana Department of Health recorded two deaths in 2011, both blamed on tap water delivered through a Neti pot, a type of sinus irrigation system that uses salt and water.
Naegleria fowleri can also enter your nose when swimming or diving. In 2021, a 10-year-old girl in Texas became infected and died, likely after swimming at a splash pad near Dallas where the organism was detected.
Naegleria fowleri isn’t the only amoeba that can cause illness or even death. A 69-year-old woman in Seattle died after apparently coming into contact with the amoeba Balamuthia mandrillaris, again via tap water in a Neti pot, although the water had been run through a Brita purifier. Balamuthia mandrillaris causes a much slower infection than Naegleria fowleri.
A third type of amoeba, Acanthamoeba, can also infect humans, according to a study in ID Cases. All are free living, which means they don’t need a host to survive, Bhimraj explained. “It’s not uncommon to find them in the environment.”
A perfect storm
Brain-eating infections are fairly uncommon because “everything has to line up perfectly,” said Juan Dumois, a pediatric infectious disease physician at Johns Hopkins All Children’s Hospital in St. Petersburg, who has seen one case in his career.
You have to first start with a water source that contains amoeba. Even then, not everyone exposed to the same infected water will get sick. The water has to enter your nose and stick. “If you just wash it out or it goes down the esophagus, it won’t cause any problem,” Dumois explained.
Even then, the infectious organisms still have a long way to go, a path that involves finding their way to one of the olfactory nerves. These nerves give you the ability to detect scents and are the same ones that are damaged in some people with COVID. The germs can crawl up the nerve into the brain and cause an infection. “If the amoeba never finds that nerve, that’s it,” Dumois said. “Otherwise, it’s bad luck from a specific series of events.”
Once lodged in your brain, Naegleria fowleri will burrow into brain tissue and consume brain cells. This then triggers the immune system to try to fight it off. “A lot of white blood cells go in there and try to destroy the amoeba and, in the process, the white blood cells cause damage as well,” Dumois said. “You actually have areas in the brain that start to be destroyed and liquefied by the inflammatory reaction of fighting off the amoeba.”
The right environment
Typically, Naegleria fowleri occur in warmer climates, which is where the organisms thrive. Most of the recorded infections occurred in 15 Southern states, with Texas and Florida counting for almost half. Infections that occur farther north, like in Michigan or Minnesota, tend to happen in the summer. The amoeba lives only in fresh water like lakes and rivers and sometimes brackish water, but not saltwater.
In general, infections peak in July and August. But experts do predict that the infections will become more common in northern areas as a result of climate change. “With climate change, the temperatures even in Wisconsin and Minnesota have been warm enough,” said Bhimraj said.
It can also be found in swimming pools that aren’t adequately chlorinated and in municipal water supplies under certain conditions. With tap water, “the problem occurs in how the water is disseminated,” Dumois explained. “The water is treated in the water plant then pumped into pipes. Then it has to go to different distances before it gets to the faucet. The longer it has to go and the longer the water sits in the pipes, the lower the chlorine level drops.” If the pipes aren’t used for a while, chlorine levels go down.
Symptoms and treatment of brain infection
Patients with PAM, the brain infection caused by Naegleria fowleri, typically start with symptoms of meningitis, which is to say fever, a stiff neck, and “the worst headache you’ve ever had,” Dumois said. Later on, they may develop seizures, hallucinate, and even fall into a coma.
According to Dumois, survival depends largely on whether the infection is correctly diagnosed and treated early on. Doctors may take a spinal tap and test for different bacteria that cause meningitis but not amoeba. “You’re only going to suspect Naegleria fowleri if they were told or asked if the patient has been in a situation where freshwater has gone up their nose,” Dumois said.
Physicians usually treat PAM with a combination of drugs including some antibiotics.
First and foremost, never use water straight from the tap to irrigate your sinuses. Water that’s been boiled for one to five minutes then cooled should be safe, as is store-bought distilled water. “That’s the kind of water you want to use,” Bhimraj said. “Why take the risk?”
Washing your face can be a risk as well. “If you can wash your face without getting water up your nose, it should be fine to wash your face with regular tap water,” Dumois said. “If you have a tendency to get water up your nose when you wash your face, you are probably doing it too vigorously anyway.”
There’s no danger if you go swimming in saltwater. You’re also safe if you swim in freshwater but don’t put your head under the surface, Dumois said. Swimming underwater, diving, splashing, water skiing, or using a water slide could lead to an unfortunate chance encounter with Naegleria fowleri. Holding your nose will help, as will wearing a well-fitting dive mask that covers your eyes and nose. “That will keep most of the water out of your nose as long as it has a good fit,” Dumois said.