Sunshine? Check. Soaring temperatures? Check. Time to hit the lake! But hold on a sec. While lakes and rivers are awesome for cooling down, there's a tiny amoeba called Naegleria fowleri lurking in some fresh water that can be fatal. Don't worry; it's super rare. But there are a few easy things you can do to stay safe while having a blast.
The disease caused by Naegleria fowleri, more commonly known as Primary Amebic Meningoencephalitis – or PAM - occurs when water enters the nose, and the amoeba travels to the brain. Because it can infect the brain and destroy brain tissue, it is often called the "brain-eating ameba."
This ameba thrives in warm freshwater reservoirs, rivers, and hot springs, according to the U.S. Centers for Disease Control and Prevention. In very rare cases, Naegleria fowleri has been found in poorly maintained swimming pools, splash pads, and other recreational venues, according to the CDC. Typically, fewer than 10 people a year in the United States get PAM, though nearly everyone who gets it dies, according to the CDC.
The Texas Department of State Health Services reports that most PAM infections nationwide take place in July, August, or September when the temperature is often hottest, and water levels are lower. While the amoeba is found worldwide, it thrives in warm water with a temperature of at least 80 degrees. It is not found in salt water.
Early symptoms include headache, fever, nausea, and vomiting. Later symptoms can include a stiff neck, confusion, loss of balance, seizures, and hallucinations. The disease progresses rapidly and usually results in death within one to five days.
Knowing about the danger of these freshwater amoebas does not mean you have to live in fear of visiting your favorite water spots, such as Possum Kingdom Lake or the Brazos River. Instead, education can help keep you and your loved ones safe.
One way to greatly reduce the risk of being infected is to avoid submerging your head when swimming in freshwater. Nose plugs can also offer an effective safeguard. The only way to completely reduce the risk is to avoid all freshwater activities. But using nose clips or a swimming mask, holding your nose while going underwater or simply not going underwater offers a way to greatly decrease the chance of infection while still allowing you to enjoy water activities. Also, avoid digging or stirring up sediment in the water.
From 1979-2019, there have been 34 primary amebic meningoencephalitis (PAM) cases reported in Texas, according to the Texas Department of State Health Services.
Because these infections are so rare and hard to detect, diagnosis sometimes happens after a person has died, according to the CDC.
The first question many have is if it can be tested for in our lakes. The Brazos River Authority does not test for the Naegleria fowleri amoeba because it is common in all surface water worldwide. Those who live in warmer-weather states such as Texas should assume there is a risk when entering all warm freshwater bodies.
Knowing a few tricks and staying on top of things can seriously lower your chances of getting sick from Naegleria fowleri. After all, prevention is the ultimate water party essential (besides sunscreen, of course)!
For more information about PAM, contact the Texas Department of State Health Services here. The Texas Health and Human Services department has a list of Naegleria fowleri frequently asked questions here.