Don’t eat my brain!

We have lots of friends and family living in Colorado.

  • Just one of the many perks of living there is the abundance of hot springs – 29 to be exact.
  • For a state that boasts plenty of hiking in warmer times and skiing in winter months, hot springs are an excellent way to soak your sore muscles.
    • I’ve certainly done this in NC, even without overworking my muscles hiking the scenic Blue Ridge trails.

Although immersed in microbiology, I don’t think of brain eating amoeba while sitting in a hot spring, boating on a river, canoeing on a lake or swimming in a lake. In fact, hot springs, lakes, and rivers are supposed to remove the stressors in our lives, are they not?

  • Where does brain eating amoeba come into the picture?


  • The reason for this post is the closing down of a lake in Iowa, not in Colorado.
    • However, my sister-in-law who does live in Colorado requested this blog post, primarily because of the abundance of hot springs and the more than 4,000 fresh water lakes and reservoirs in her state.
  • On Friday, July 8, the Iowa department of health temporarily closed the Beach at Lake of Three Fires. 
  • A recent visitor who went swimming in that lake ended up getting a rare, but life-threatening infection of the brain caused by the brain eating parasite called Naegleria fowleri.
    • The medical term for this disease is primary amebic meningoencephalitis.


  • Illness begins about 1 – 9 days after the parasite swims up the person’s nose.
  • Signs and symptoms include:
    • a severe headache in the forehead or temples,
    • fever,
    • nausea and vomiting
  • Later symptoms include:
    • stiff neck,
    • seizures,
    • altered mental status including hallucinations, followed by
    • coma and even death.
      • Most people will die in 1 – 18 days once symptoms begin.


  • Only four people out of 154 known infected individuals in the U.S. from 1962 to 2021 have survived – this gives us a fatality rate of 97.4%.
    • To put things in perspective, Ebola virus can show up to 90% mortality.


  • The below image shows you the number of case reports of primary amebic meningoencephalitis caused by Naegleria fowleri in the United States.

Mind you, this is a rare infection – we have seen only 154 cases in this country from 1962 to 2021.

  • As you can see from the image, aquatic venues are usually the culprit.
    • These venues refer to structures that are artificially constructed or modified from their natural state so that the general public can use the water for recreational or therapeutic purposes.
      • Such structures include swimming pools, interactive water play venues, water playgrounds, hot tubs & spas, and artificial whitewater rivers.
  • Such venues need to ensure adequate chlorination of the water at all times – the importance of this is underscored by the fact that the CDC has not seen any brain-eating ameba infections in aquatic venues that are well-operated, i.e. where the chlorine levels are adequately managed and maintained.

You can also see from the above image that tap water has been a source of infection a few times.

  • Scary? Yes.
  • But it is important to know that these infections were caused by tap water being forced up the nose – such as when used to rinse out your sinuses using neti pots or similar devices.
    • So if you are going to rinse out your sinuses, the CDC recommends using water that is preferably boiled or distilled and if that is unavailable, to use filtered water.
    • If these options are unavailable, then use water that has been disinfected.
      • Click HERE for more information on disinfecting water.


  • This parasite usually thrives in bodies of warm freshwater such as hot springs, lakes, and rivers.
  • We never think of parasites hitching a free ride up our noses as we dive in or dunk our heads in a fresh lake on a hot summer day.
    • And lately, our summer months have been getting hotter and hotter.
  • April to November is when we have seen Naegleria fowleri infections in the past, with most infections occurring in July, August, and September.

The good news is that you cannot get infected with Naegleria fowleri by drinking contaminated water.

  • You can only get infected when contaminated water goes up your nose, from where it can reach the brain.
  • Another bit of good news is that this parasite has not been shown to spread via water vapor or aerosol droplets such as those created in showers or from a humidifier.

The below image shows you all the states where we have seen Naegleria fowleri in the last 59 years.

  • One immediate change will be adding Iowa to the list of states with 1 case reported, similar to Indiana, Mississippi, Missouri, Nevada, New Mexico, and Tennessee.


The CDC recommends certain behaviors based on common sense and not on any scientific testing since the low numbers of infections make it difficult to show whether these recommendations are actually effective.

  • When swimming in warm freshwater bodies of water or participating in recreational water activities, do the following:
    • hold your nose shut or use nose clips
    • keep your head above water
    • do not put your head under the water in hot springs and other untreated thermal waters
    • much as you will want to, avoid water-related activities in warm freshwater
    • don’t dig up or stir up the sediment while taking part in water-related activities in shallow, warm freshwater areas
      • these parasites live off the bacteria found in the river/lake sediment


According to NASA, our planet is warming much faster than it has in the past.

  • Not only have the air temperatures over Earth’s surface gone up about 2 degrees Fahrenheit in the last century, the last five years have been the warmest five years in centuries!
  • We use chlorine to kill many potential pathogens, including Naegleria fowleri in swimming pools and other recreational water bodies.

However, the use of chlorine comes with its own repercussions for the planet, from creating previously unidentified toxic byproducts in water, according to a research study done in collaboration with scientists from Switzerland, Johns Hopkins University, and University of California, Berkeley.

  • In addition, chlorine can destroy ozone in our atmosphere – which in turn, contributes to global warming.


  • Science seems to indicate that the planet is getting hotter, which does allow Naegleria fowleri and other opportunistic pathogens to get even closer to us.
    • However, incidence of Naegleria fowleri infections are very rare.
      • Moreover, we do know how to protect ourselves:
        • basically, prevent water, especially untreated or unclean water from going up our noses
  • As to avoiding chlorine in our water, European countries do not use chlorination as often and they still manage to keep their water safe from many waterborne diseases.
    • Perhaps it is time for us to invest in those technologies!

Stay healthy, my friends. Until next time.


SNOTI Inc. (Say No To Infections)

For more information, visit:

Leave a Reply

Your email address will not be published.