Brain-Eating Amoeba

The brain-eating disease from swimming is caused by an amoeba, Naegleria fowleri. This thing of nightmares is a single-celled living organism. It loves hot, fresh water up to 115 degrees Fahrenheit and lives all over the world. It loves to live in your favorite lakes in the Southern United States. Though this amoeba can survive in cooler climates in the sediment of rivers and lakes-it is most common in warmer climates and grows in warm fresh waters. This may have played a part recently in the first known case of a child in Nebraska. It is not normal to see infections from amoeba in colder climates. The amoeba may have simply been in the sediment and grew after the recent heat waves that have plummeted the US.

It has also been found in contaminated tap water, hot-water heaters and unsanitized pools. 

While there are very few infections from it, this amoeba is quite common in the environment. When it does infect a human it enters through the nose and goes to the brain. It causes primary amoebic meningoencephalitis, PAM. PAM is the destruction of brain tissue leading to brain swelling. The initial symptoms are fever, nausea, frontal headache and vomiting. Most patients die within 5 days but some have lived for 18 days. Less than 3% of those infected have survived this disease. 

How do I get this infection?

Diving into warm, fresh waters such as lakes and rivers during the hottest months of the year can increase your chance of getting a Naegleria infection as it pushes the water into your nose as you dive close to the bottom where the sediment is.

While hurricanes start in salt water that doesn’t harbor this amoeba, they do wreak havoc on our fresh water supplies and resources. They travel across a state churning up the sediment of fresh water lakes and rivers that may increase the risk of amoeba exposure during swimming.

One of the 2 cases of this infection from a nasal saline rinse in the US was due to a Hurricane. Hurricane Katrina in 2005 damaged the fresh water supply system in Louisiana leading to tap water contaminated with Naegleria fowleri that was used in the nasal rinse. 

There have also been cases from a contaminated swimming pool and a slip-n-slide.

81% of infections in the US have been in children. Infections occur more in the warmest months of the year; July, August, and September. The US has 0-8 infections per year. Remember this is not a common infection. Most of the infections in the US have been in southern states, though 2 have happened in Minnesota until this recent Nebraska infection.

Here is the number of cases total per state from 1962-2021:

• • Texas: 39
  • Florida: 37
  • California: 10
  • South Carolina: 8
  • Arizona: 8
  • Virginia: 7
  • North Carolina: 7
  • Oklahoma: 7
  • Arkansas: 6
  • Georgia: 5
  • Lousiana: 4
  • Kansas: 2
  • Minnesota: 2
  • Nevada, Missouri, New Mexico, Tennessee, Indiana, Mississippi: 1

How can I avoid getting this amoeba?

Most infections come from swimming in freshwater lakes and rivers in the warm months. I think this would be hard to avoid if you are a kid in August in Florida! Remember this is a rare disease. There are anywhere from zero to eight per year in the entire US. You are more likely to be bit by a shark in salt water at about 60 attacks per year in the US. And by the looks of the beaches in Florida, it doesn’t appear anyone is avoiding the salt water! 

It may be prudent to not dive into fresh water on warmer days or during July, August and September, especially if you live in Florida or Texas. Though simply putting your head underwater can lead to a brain infection. 

You can more easily avoid the infection caused by tap water. Follow your water company notices. If there is a boil order do not put your head underwater such as in the bath.

Always boil tap water that will be used for nasal lavage. Please don’t forget to cool it back down to room temperature before using it!

Always keep your pools sanitized properly. 

Can I get the brain-amoeba from water in my mouth?

No, you can not get Naegleria infection by drinking water, so this isn’t a concern. Remember this amoeba must enter through your nose to get to your brain. Let me emphasize this again, you CAN NOT get this infection from drinking your tap water.

How do you check for Naegleria?

There are tests for the amoeba. But it is often diagnosed after death due to the rapid course of disease onset to death. 

How is the brain-eating amoeba treated?

It is unclear whether there is a treatment yet. Two people have recently survived this infection with a new medication, miltefosine. It is not yet clear if this drug is the reason for the survival or if it is due to the other medicines and aggressive brain swelling management of these patients. 

How would I know if I had the amoeba?

First, you would need exposure-such as your head underwater in an unsanitized pool, warm fresh-water source, or contaminated tap water. You may also get exposed by using unboiled tap water in a nasal lavage.
The symptoms will appear 1-9 days after this exposure. This usually happens at about 5 days.

Initial symptoms:

• • Fever
  • Nausea
  • Severe frontal headache
  • Vomiting

Late symptoms:

• • Stiff neck
  • Seizures
  • Altered Mental Status
  • Coma
  • Hallucinations

If you do have any of these symptoms, especially with a known exposure, please seek immediate medical attention.