Summer is nearly here, bringing warmer temperatures to the air and to surface water. Popular summer activities usually involve water; whether those activities take place on a lake, a river, or in a water park, something is lurking that everyone should be aware of.

It’s a microscopic organism living in warm freshwater called Naegleria fowleri, commonly known as the “brain-eating amoeba,” and it has the potential to cause a severe, deadly brain infection called primary amebic meningoencephalitis (PAM).

What is Naegleria fowleri?

Naegleria fowleri is a single-celled amoeba that is commonly found in surface water environments such as rivers and lakes and occasionally in poorly maintained swimming pools and splash pads. 

It thrives in both soil and water with temperatures above 77 degrees Fahrenheit. The amoeba is harmless unless it enters the body through the nose, usually when a person is swimming, diving or water skiing.  

Understanding the infection process:

When Naegleria fowleri enters the nasal passages, it travels to the brain along the olfactory nerve, causing the infection known as PAM. PAM is a rare and devastating illness that affects the central nervous system. Once in the brain, Naegleria fowleri rapidly destroys brain tissue, leading to severe inflammation and often resulting in a fatality.

Initial PAM symptoms include headache, fever, nausea, and vomiting. Since PAM is known to progress rapidly, later symptoms may include a stiff neck, confusion, loss of balance, seizures, and hallucinations. According to the Centers for Disease Control and Prevention (CDC), it can take anywhere from two to fifteen days for symptoms to appear, and the infection usually kills the individual within an average of five days after the first symptoms show up. 

Because the disease is so rare and hard to detect, a diagnosis is usually made after the patient has died. According to CDC records, there were 157 cases of PAM reported from 1962 to 2022. Texas and Florida have the highest counts, with 39 and 37 cases, respectively. As of 2022 data, 97% of cases end in a fatality, with only four people having survived Naegleria fowleri.

How do you prevent a Naegleria fowleri infection?

You don’t have to avoid all freshwater. Here are some preventative steps you can take: 

1.    Avoid jumping or diving into bodies of warm freshwater, especially during the summer.
2.    Hold your nose shut, use nose clips, or keep your head above water when in bodies of warm fresh water.
3.    Avoid putting your head underwater in hot springs and other untreated geothermal waters.
4.    Avoid digging in, or stirring up, the sediment in shallow, warm fresh water. The amoeba are more likely to live in sediment at the bottom of lakes, ponds, and rivers.
5.    Avoid placing your face directly in the path of water shooting up from a splash pad. Again, holding your nose or using nose clips is vital.

It’s imperative to seek immediate medical attention if you or someone you know develops a headache, fever, or vomiting after swimming or playing in freshwater. 

The State Health Department has a list of Naegleria fowleri frequently asked questions here. The Texas Department of State Health Services is another resource you can contact at 888.963.7111 for additional information on Naegleria fowleri. 

While Naegleria fowleri infections are exceptionally rare, it is crucial to be aware of the risks and take appropriate preventive measures, especially when participating in water activities in warm, freshwater environments. 

If you or a family member becomes ill after experiencing freshwater in the nasal cavity, it is imperative that you seek medical attention. Early symptoms are very similar to the flu, and because of that, most people expect symptoms to pass with time. However, because this illness progresses quickly, fast identification of the parasite is crucial. Seek medical attention and inform your healthcare provider of nasal contact with surface water so that appropriate testing may be performed quickly.

Following the suggested preventive tips and staying informed can significantly reduce the chances of infection by Naegleria fowleri. 

Remember, prevention is key when it comes to such rare but potentially severe infection.