Swimming in fresh water is a popular way to cool off during the summer, but it also carries a rare but deadly risk: brain-eating amoebas. These microscopic organisms can cause a fatal brain infection called primary amebic meningoencephalitis (PAM) if they enter your nose and reach your brain. Here are some facts and tips to help you stay safe and enjoy the water.What are brain-eating amoebas?
Brain-eating amoebas are a type of single-celled organism called Naegleria fowleri. They are found in warm and shallow fresh water, such as lakes, rivers, and hot springs. They can also live in soil. They are not found in salt water or properly chlorinated pools.
Despite their nickname, these amoebas do not actually eat your brain. They cause damage and inflammation by releasing toxins that destroy the brain tissue. The infection is very serious and often leads to death.How do you get infected by brain-eating amoebas?
The most common way to get infected by brain-eating amoebas is by swimming, diving, or doing other water activities in contaminated fresh water. The amoebas can enter your nose and travel to your brain through the olfactory nerve. You cannot get infected by swallowing the water or by having contact with an infected person.
The infection is very rare, but it can happen anywhere in the world where the amoebas are present. In the United States, most cases occur in the southern states, especially Florida and Texas, where the climate is warmer. However, some cases have also been reported in northern states during heat waves. What are the symptoms of infection by brain-eating amoebas? The symptoms of PAM usually appear within one to two weeks after exposure to the amoebas. They include:
- Severe headache
- Nausea or vomiting
- Stiff neck
- Light sensitivity
- Loss of balance
The symptoms can worsen rapidly and lead to coma and death within a few days. The infection is often mistaken for bacterial or viral meningitis, which can delay the diagnosis and treatment.How is the infection diagnosed and treated?The diagnosis of PAM is based on the symptoms, medical history, and laboratory tests. The tests may include:
- Lumbar puncture (spinal tap) to collect cerebrospinal fluid (CSF) and look for the amoebas or their DNA.
- Brain imaging (CT scan or MRI) to check for swelling or bleeding in the brain.
- Biopsy of brain tissue to confirm the presence of the amoebas.
The treatment of PAM is challenging because most antibiotics and antifungal drugs do not work against the amoebas. The only drug that has shown some effectiveness is miltefosine, which was originally developed to treat a parasitic infection called leishmaniasis. Miltefosine is not widely available and has serious side effects, such as nausea, vomiting, diarrhea, and kidney damage.Other treatments that may be used along with miltefosine include:
- Anticonvulsants to control seizures.
- Steroids to reduce inflammation.
- Cooling therapy to lower body temperature.
- Supportive care to maintain vital functions.
The survival rate of PAM is very low, less than 5%. However, some cases of recovery have been reported with early diagnosis and aggressive treatment.How can you prevent infection by brain-eating amoebas?The best way to prevent infection by brain-eating amoebas is to avoid swimming or diving in warm and shallow fresh water where they may be present. If you do swim in such water, you can reduce your risk by following these tips:
- Wear a nose clip or hold your nose shut when you go underwater.
- Avoid stirring up the sediment at the bottom of the water.
- Do not swim in areas that are posted with signs warning about the amoebas.
- Do not swim in water that is visibly dirty or smells bad.
If you use a neti pot or other device to rinse your sinuses, make sure you use sterile or filtered water that has been boiled for at least one minute and cooled down. Do not use tap water or untreated well water.If you develop any symptoms of PAM after swimming in fresh water, seek medical attention right away. Early diagnosis and treatment may improve your chances of survival.
Brain-eating amoebas are a rare but deadly threat that can cause a fatal brain infection if they enter your nose while swimming in fresh water. The infection is very hard to diagnose and treat, so prevention is key. Avoid swimming in warm and shallow fresh water where the amoebas may be present, or wear a nose clip if you do. If you have any symptoms of PAM, see a doctor immediately.