Recently a child in Douglas County died from a rare infection caused by the Naegleria fowleri amoeba, acquired while swimming in the Elkhorn River. The Centers for Disease Control and Prevention has confirmed that this was indeed Naegleria fowleri, the organism responsible for a brain infection called primary amebic meningoencephalitis.
Understandably, many people have questions about how safe it is to spend time in freshwater sources like rivers, lakes and streams. Here are five things to keep in mind about this infection and your safety.
1. Keep the risk of infection in perspective
“We know this amoeba is in many freshwater water sources and soil samples. It doesn’t necessarily mean we need to be overly worried,” says Mark Rupp, MD, Nebraska Medicine infectious diseases specialist.
“This infection is rare, especially compared to other activity risks in and out of the water. Statistically, fewer than 30 cases have been reported in 10 years. As we decide what recreational activities to participate in, take precautions and keep the risk in perspective.”
2. Take precautions to reduce risk
Freshwater warms up in the later summer months, increasing algae and bacteria. Amoebas that normally would be found in the mud feed off this bacterium.
This single-cell organism infects people when water containing the amoeba enters the body through the nose and into the olfactory area, usually while swimming, jumping, or diving in lakes or rivers.
Limiting opportunities for freshwater to get into the nose is the best way to reduce the risk of infection. Although the odds of infection are low, take these precautions to reduce infection risk:
- Keep your head above water and avoid submerging
- Avoid water entering your nose; use a nose plug or clip instead
- When swimming, avoid jumping in the water
- Avoid digging or stirring up the bottom of the lake or river
- Avoid high-speed water activities like water skiing or aggressive tubing
3. How the Naegleria fowleri infection is not passed
What we know right now is that the infection is not passed from person to person, nor can a person be infected by drinking contaminated water.
4. Naegleria fowleri symptoms after fresh water exposure
Symptoms typically occur anywhere from one to 12 days, with the average symptom appearance at five days. If you start noticing symptoms after exposure, watch to see if they are progressive and seek medical attention if they persist.
The initial, generalized symptoms include:
- Headache
- Nausea or vomiting
- Fever
Progression of symptoms include:
- Stiff neck
- Confusion
- Seizures
- Other neurological symptoms
5. Diagnosis and treatment for the Naegleria fowleri infection
This type of infection is aggressive, with death occurring in 97% of cases. Diagnosis requires test evidence of the amoeba from brain tissue of cerebral spinal fluid.
A small number of cases of people who have survived with early intervention have been reported. Miltefosine appears to have some effect when combined with other drugs (antifungal or antibacterial medications). Nebraska Medicine has access to this type of treatment.
