With one death reported, how great is the risk from 'brain-eating' amoeba

Naegleria fowleri, a rare and dangerous organism known popularly as the "brain-eating amoeba," has claimed a Louisiana life.
Eight-year-old Lillian Smart of Ruston died over the weekend, within days of the Louisiana Department of Health’s announcement that a case had been confirmed in the state.
According to mother Rebecca Smart’s Facebook page, the girl was feverish on Aug. 13. By Aug. 16, Lillian was hospitalized with a fever and double vision. Rebecca Smart asked for prayers that the medication her girl needed would arrive in time.
The medication arrived, but it didn’t stop the infection. After Lillian died, Gov. Jeff Landry said on X, “Heartbroken over the news of Lillian’s passing,”
Infection by the amoeba is rare. Lillian’s was the first Louisiana case in 13 years.
But officials nevertheless pointed to Centers for Disease Control and Prevention guidance on the condition. We print much of that guidance here.
The rare Naegleria fowleri  is a free-living amoeba, a kind of one-celled organism that thrives in warm freshwater lakes, rivers, and hot springs.
•It is often called the “brain-eating amoeba” because it can infect the brain and destroy brain tissue.
•Brain infections caused by Naegleria fowleri are very rare but nearly always fatal.
Naegleria fowleri lives in soil and warm freshwater lakes, rivers, ponds and hot springs around the world.
In very rare cases, Naegleria fowleri has been found in poorly maintained swimming pools, splash pads, and other recreational venues. The amoeba also has been found in tap water.
If water containing the amoeba goes up the nose and to the brain, it can cause an infection called primary amebic meningoencephalitis, or PAM.
Typically, fewer than 10 people a year in the United States get PAM. Nearly everyone who gets PAM dies from it.
Between 1962 and 2024, there were 167 reported cases of PAM in the United States. Only four have survived.
Naegleria fowleri  infects people by traveling up the nose and to the brain, where it consumes brain tissue.
Signs and
symptoms
Early symptoms of PAM can include headache, fever, nausea and vomiting. PAM progresses rapidly. Most people with PAM die within one to 18 days after symptoms begin. It usually leads to coma and death after five days.
As PAM progresses, symptoms can include stiff neck, confusion, lack of attention to people and surroundings, loss of balance, and hallucinations.
Exposure risks
Brain infections caused by Naegleria fowleri usually occur after someone goes swimming or diving in a lake, river, or other fresh water during summer months. Infections often happen when it’s been hot for long periods, resulting in higher water temperatures and lower water levels.
A few infections have occurred when people used tap water that contained Naegleria fowleri to rinse their sinuses or cleanse their nasal passages.
In very rare instances, people have become infected from recreational water like splash pads and a surf park that did not have enough chlorine.
You cannot get a Naegleria fowleri infection from swallowing water containing the ameba. You also can’t get an infection from someone else or pass it on to others.
Reducing risk
To help protect yourself against a Naegleria fowleri infection:
•Hold your nose or wear a nose clip if you are jumping or diving into fresh water.
•Always keep your head above water in hot springs.
•Don’t dig in shallow water because the amoeba is more likely to live there.
•Use distilled or boiled tap water when rinsing your sinuses or cleansing your nasal passages.
A Naegleria fowleri infection is diagnosed using laboratory tests.
These tests are available in only a few labs in the United States, including CDC.
Because these infections are so rare and hard to detect, diagnosis sometimes happens after a person has died.
Contact a health care provider immediately if you or a loved one is experiencing symptoms of PAM.
Treatment
and recovery
Naegleria fowleri can cause PAM which destroys brain tissue and causes the brain to swell. Unfortunately, more than 97% of people with PAM have died from the infection.
PAM progresses very quickly. This has made treatments for the disease difficult to identify. There is some evidence that certain drugs may be effective.
What CDC is doing
CDC’s Free-Living and Intestinal Amoebas Lab is one of only a few labs in the country that can identify Naegleria fowleri. 
It is experienced in diagnosing Naegleria fowleri infections and can provide results quickly.
Free-living amoebas
A free-living amoeba is a kind of one-celled organism that lives in water and soil around the world.
Most people will come into contact with these amoebas during their lives but won’t get sick. Others will develop rare but serious infections.
Although there are several types of free-living amoebas that live in the environment, three are known to cause severe disease in people:
Acanthamoeba
Balamuthia mandrillaris
Naegleria fowleri
All of these amoebas can cause life-threatening brain infections. Some can also cause infections of the eyes, skin, sinuses and other parts of the body.