Naegleria fowleri is a brain-eating amoeba that lives in warm freshwater (such as lakes, rivers, hot springs, and ponds).
It can enter the human body through the nostrils and be potentially life threatening.
Naegleria fowleri causes the disease primary amebic meningoencephalitis (PAM), a brain infection that leads to the destruction of brain tissue. It is rare with only 135 reported cases since the amoeba was identified in 1960.
According to the Centers for Disease Control and Prevention (CDC), infections are most likely to occur when it is hot for prolonged periods of time. Heat waves cause higher water temperatures and lower water levels.
American Camp Association (ACA) has compiled the following four tips to help understand the issues related to this potentially fatal disease:
1. Understand that while extremely rare, three cases of Naegleria fowleri causing Primary Amebic Meningoencephalitis have been reported in 2014.
2. Recognize that Naegleria fowleri is most commonly found in freshwater lakes in southern-tier states during the summer, and that infections are most likely to occur when the weather is hot for prolonged periods of time. Assess risk when utilizing your freshwater lake, pond, or river.
3. If one shows signs of headache, fever, nausea, vomiting, or stiff neck, seek immediate medical attention.
4. While not a guarantee, the CDC recommends the following preventive measures when swimming in warm bodies of freshwater: avoid water-related activities in warm freshwater during periods of high water temperature and low water levels; hold the nose shut or use nose clips when taking part in water-related activities in bodies of warm freshwater; and avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.
The organism thrives on the nutrients in the organic sediment in a body of freshwater. When stirred, Naegleria fowleri are free floating.
The Naegleria fowleri amoebae then swim up a swimmers nose, burrow into the brain and eat it rapidly. Infection cannot be spread from one person to another, and you cannot be infected with Naegleria fowleri by drinking contaminated water.
There is currently no rapid or routine test to determine if Naegleria fowleri is present in the water (the tests that are available can take weeks), but new detection tests are under development.
Initial symptoms of PAM start one to seven days after infection. The initial symptoms include headache, fever, nausea, vomiting, and stiff neck. Later symptoms include confusion, lack of attention to people and surroundings, loss of balance, seizures, and hallucinations. After the start of symptoms, the disease progresses rapidly and can cause death within one to twelve days.
While clinical studies have shown that several drugs are effective against Naegleria fowleri in the laboratory, their effectiveness is unclear since almost all infections have been fatal, even when people were treated.
Since, according to the CDC, Naegleria fowleri is found in many warm freshwater lakes and rivers in the United States, particularly in southern-tier states, it is likely that a low risk of Naegleria fowleri infection will always exist with recreational use of warm freshwater lakes, rivers, and hot springs.
The low number of infections makes it difficult to know why a few people have been infected compared to the millions of other people using the same or similar waters across the US. The only certain way to prevent a Naegleria fowleri infection is to refrain from water-related activities in or with warm, untreated, or poorly-treated water.
CDC created the national Free-living Ameba (FLA) Laboratory in 1978, which has become a national and global leader for diagnostic expertise and clinical guidance. As a national resource for health departments and clinicians, CDC’s FLA laboratory diagnoses most Naegleria fowleri infections in the U.S. In 1989, CDC began formally tracking Naegleria fowleri infections.
Additional information is available from the following two organizations.
American Camp Association (ACA)
Centers for Disease Control and Prevention (CDC)
As Yogi Berra said, “It’s tough to make predictions, especially about the future.”