Waterborne Illness — Primary Amebic Meningoencephalitis and Naelgeria Fowleri

Girl in Lifejacket By Lake

The June 22 and July 13, 2016 deaths of two teenagers due to Primary Amebic Meningoencephalitis (PAM) caused by the brain-eating amoeba, Naegleria fowleri, has brought renewed light to this rare infection.  

According to the Centers for Disease Control and Prevention (CDC) Naegleria fowleri infections are very rare, yet devastating. From 2005 to 2015, 37 infections were reported in the U.S. All but two were fatal. 

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 is potentially life threatening. Naegleria fowleri causes the disease Primary Amebic Meningoencephalitis (PAM), a brain infection that leads to the destruction of brain tissue. According to the 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. ACA has compiled the following information to help camps understand the issues.

Top Four Tips for Camps

  1. Understand the facts: People are infected when water containing the amoeba enters the body through the nose. Recreational water-associated infection most often occurs when people go swimming or diving during the summer in warm freshwater places, like lakes and rivers. Review the Naegleria fowleri FAQ's from the Centers for Disease Control and Prevention.
  2. Assess risk: Recognize that Naegleria fowleri is most commonly found in freshwater lakes 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. Review the resources below.
  3. Prevention: 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;
    • avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.
  4. Training: Ensure that your camp health care staff understand the signs and symptoms of this infection. Symptoms can be mild at first, but they worsen quickly. Furthermore:
    • symptoms usually start about 5 days after infection (but can range from 1–9 days). 
    • symptoms can include headache, fever, nausea, or vomiting.
    • later symptoms can include stiff neck, confusion, lack of attention to people and surroundings, loss of balance, seizures, and hallucinations.
    • after symptoms start, death most often occurs within about 5 days (but can range from 1–12 days).
    • seek medical help immediately if any symptons are presented.

"You cannot be infected with Naegleria fowleri by drinking contaminated water, and the infection cannot spread from one person to another." — Centers for Disease Control and Prevention

Can We Eliminate Naegleria fowleri from Our Camp’s Lake or Pond?

Experts disagree on whether Naegleria fowleri can be eliminated from specific bodies of water. Some claim that if the organic sediment in lakes is biodegraded until it is no longer present, Naegleria fowleri would have no place to incubate. However, the CDC states that there are no means yet known that would control naturally occurring Naegleria fowleri levels in lakes and rivers making prevention difficult. Discuss your situation with an expert.

Contracting the Infection

While infections with Naegleria fowleri are very rare, they have occurred mainly during the summer months of July, August, and September. Infections have been more likely to occur in southern-tier states of the US, but can also occur in other locations.Infections usually occur when it is hot for prolonged periods of time, which causes higher water temperatures and lower water levels. Infections can increase during heat wave years. The organism thrives on the nutrients in the organic sediment in a body of freshwater. The level of phosphorus and nitrogen in organic sediment is typically about a thousand times the level found in the water column. When stirred, Naegleria fowleri are free floating. The Naegleria fowleri amoebae then swim up a swimmers nose, burrow into the brain and eat rapidly. Infection cannot be spread from one person to another, and you cannot be infected with Naegleria fowleri by drinking contaminated water.

Treatment

If a camper or staff person develops a sudden onset of fever, headache, stiff neck, or vomiting, trained medical care should be immediately secured. 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.

Resources