Skip to main content
A swimmer enjoying the springs at Ichetucknee Springs State Park.

A Quick Guide to Brain-Eating Amoeba

Every few years, a parasite commonly referred to as Brain-Eating Amoeba starts to attract attention for its sudden and often fatal impact on humans. According to the Center for Disease Control and Prevention (CDC), only three of the 138 people known to be infected survived. From 2006 to 2015, 37 infections were reported and all but two were fatal. The good news is amoeba infection, and the resulting illness, are rare and often avoidable.

The Pathogen and Life Cycle of Naegleria fowleri.

The Pathogen and Life Cycle of Naegleria fowleri. Courtesy of CDC

What is Brain-Eating Amoeba?

The term “amoeba” describes hundreds of organisms and can also be spelled “ameba.”

Naegleria fowleri is the species commonly referred to as Brain-Eating Amoeba. Naegleria fowleri is a single-celled organism that loves warm freshwater, such as the lakes and ponds, found in Central Florida. Brain-Eating Amoeba is found worldwide.

The often-fatal illness caused by Brain-Eating Amoeba is “Primary Amoebic Meningoencephalitis” (PAM). Fortunately, PAM is exceedingly rare in Florida and the rest of the United States.

How Do Brain-Eating Amoebas Infect People?

Brain-Eating Amoeba infects people when contaminated water travels up the nose. This usually occurs as people take part in freshwater recreational activities. After an amoeba enters the body, through the nose, it travels to the brain where it can cause Primary Amoebic Meningoencephalitis (PAM). PAM destroys brain tissue and can cause swelling and death.

Infections usually occur in July, August, or September; however in Florida, the season may range earlier and later due to our prolonged hot weather. Naegleria fowleri is not found in salt water (like the ocean) and infections can not spread from person to person.

How Can You Avoid “Brain-Eating Amoeba?

Male swimmer in a Florida river snorkeling and observing the clear spring-fed river system.

UF/IFAS Photo by Tyler Jones.

Naegleria fowleri is usually found in the sediments of warm water. Therefore, the best way to avoid infection is to avoid stirring up bottom of Florida lakes, rivers, ponds, or other bodies of water. Discourage children of all ages from digging around in the shallows or diving down to dig in the sediments. Reduce your risk of infection by keeping your face away from the bottom sediments in warm water.

You cannot get infected by drinking contaminated water or by eating fish from water containing Brain-Eating Amoeba. The only way to ‘catch’ Brain-Eating Amoeba is by having water containing the amoeba enter the nose.

Avoid playing or swimming in warm shallow water during the summer months to reduce your risk. Avoid warm, shallow, or stagnant water when water skiing, tubing, or jet-skiing as these activities can cause water to be forced up the nose. Protect yourself and your family further by encouraging those playing or swimming in warm water to wear ear plugs and a nose clip. According to the CDC, “These recommendations make common sense but are not based on any scientific testing since the low numbers of infections make it difficult to ever show that they are effective.”

What are the Symptoms of PAM?

According to the Center for Disease Control and Prevention (CDC), symptoms may be mild at first but will worsen quickly. The CDC lists the following symptoms:

  • Symptoms usually start 5 days post-infection but may range from 1-7 days post-infection
  • Typically include headache, fever, nausea, or vomiting
  • Later symptoms can include stiff neck, confusion, loss of balance, seizures, hallucinations, and lack of attention to people or  surroundings
  • After symptoms begin, the illness typically causes death within 5 days but may range from 1-12 days

Contact your doctor immediately, if you suspect infection after playing or swimming in warm water. In the few known cases of survival, the patients recognized the symptoms early and administered proper treatment quickly. Seek treatment  immediately to improve chances of success.

Where Can I Find More Information?

For more information on infection rates, prevention, or information En Español, visit the Center for Disease Control and Prevention’s brain-eating amoeba website,, or contact them at 800-CDC-INFO (800-232-4636).

For more information on Florida lake conditions that may favor ameba, read Florida LAKEWATCH’s publication, Amoebas in Lakes or, contact them at 1-800-LAKEWATCH (800-525-3928). You can visit their website at




20 Comments on “A Quick Guide to Brain-Eating Amoeba

  1. Thank you for publishing this important information. I have friends, a pediatric hospitalist and an infectious disease specialist who lost their beloved son to this disease. They spread the word about amoebic infection wherever they can and I appreciate that it was put into the Master Gardener newsletter.

    • Jane, I’m so sorry to hear about your friends’ loss. Please feel free to share this information or the newsletter with anyone you wish. Thank you for your comment and encouragement.

  2. Im a nervous wreck about this i work in lakes and get water in my nose frequently

    • Hi Frank,
      I understand your concern. The good news is that infections are very rare. The chances of infection are highest in shallow lakes and ponds during the hottest months of the year. The CDC made some recommendations to lower personal risk even further:
      – Hold your nose shut, use nose clips, or keep your head above water when taking part in water-related activities in bodies of warm freshwater.
      – Avoid putting your head under the water in hot springs and other untreated thermal waters.
      – Avoid water-related activities in warm freshwater during periods of high water temperature.
      – Avoid digging in, or stirring up, the sediment while taking part in water-related activities in shallow, warm freshwater areas.

  3. Anyway this can live in bottled water ? Maybe a silly question but I really would like to know .

    • There is no such thing as a silly question when were are talking about something as dangerous (although also rare) as Naegleria fowleri. As I tell almost everyone who asks me for a “yes” or “no” answer about a dangerous thing in nature or the environment, my response is, “highly unlikely but not impossible.”
      According to the CDC, and mentioned in this blog post, “You cannot get infected from drinking water contaminated with Naegleria. You can only be infected when contaminated water goes up into your nose.”
      That said, if you were to use bottled water or tap water for nasal irrigation (AKA using a “neti pot” or other similar device) I would strongly urge you to follow CDC recommendations and use pre-boiled and cooled water. Technically, most drinking water sources will be filtered or purified in such a way that would likely exclude all brain-eating amoeba, but for safety’s sake, please follow CDC recommendations on this. You can find them here:
      If you are referring to simply drinking water, rather than pouring it into your nose, then there is likely a similarly low risk of contracting Naegleria fowleri from drinking tap water as there is from drinking bottled water. There are too many variables to give you a “yes” or “no” answer, unfortunately.
      The most important thing to be aware of is the processing your water goes through. In most cases, the is very little difference between tap water and bottled water except personal preference, cost, and taste. In fact, in some cases, bottled water may simply be tap water (from one or more cities) but packaged and sold. However you prefer your water, I encourage you to look into the water quality reports and water processing methods for the brand or source you are interested in.

  4. Thank you for taking the time , I have looked elsehwere for information on this , but have not had much luck. My child was lying down drinking bottled water and it went up his nose , so I, as a mother, of course have this amoeba in the back of my head . Weird thing is today (3 days later ) he is running a fever so , hopefully its a coincidence with being back to school, but I was trying to get some info on it.

    • I understand completely. Every time I jump in a lake, pool, or river, I get a flash of panic if water goes up my nose. I’m much better about remembering to hold my nose when I jump now! 🙂
      While the symptoms are listed above in the blog post, please refer to your doctor’s advice if you’re concerned it may be more than a back-to-school cold.
      I hope your son feels better soon, if he doesn’t already, and I am so glad to know you found my post and reply helpful.

  5. i was chatting with a gal quite along time ago in a health area of a department store , where they had scales and told she is loosing weight rapidly from eat raw succhi that came from a warm waters in the Caribbean, and it was determined at the time, that she had an amoeba eating away at her insides, and no way of riding her body of this amoeba, and lost 40lbs in a matter of weeks. Of course this conversation took place about 10 years ago.

    question, is it possible to contract amoebas from eating fresh warm water fish?

    appreciate your response

    • Hi Rochel,
      There are hundreds, if not thousands of species of bacteria, amoeba, and other microorganisms that can cause us harm; however, this particular species cannot be caught by eating freshwater fish. The only way to be infected with Naegleria fowleri is by allowing contaminated water to be forced up the nose.
      Hope this helps,

  6. Thanks for the post! very useful information.

    I live in the diamond village in ufl, and today I used a neti pod filled with tap water (mixed with cold tap water and hot tap water) to irrigate my nasal. and I immediately realized that it might be a bad idea. After googled it for a few minutes, I am totally freaked out right. I was wondering how rare is it in the tap water? I learned that it likes hot water.

    • Hi Alan,
      Great question. Unfortunately, I can’t give any kind of statistic as to how rare or how frequent Naegleria fowleri is in any given tap water other than to say that is considered very rare. Generally speaking, tap water is considered safe due to its municipal water treatment process, if you are on municipal supply (as opposed to a home well-water system, for instance). As a Diamond Village resident, you are on a municipal supply provided to UF’s Campus by Gainesville Regional Utilities (see here for more information:

      All that said, the CDC strongly recommends the following for water used in nasal rinsing:
      – Boil (Preferred): Use water that has been previously boiled for 1 minute and left to cool.
      – Buy (Preferred): Use water with a label specifying that it contains distilled or sterile water.
      – Filter (If Buying or Boiling is not possible): Use a filter designed to remove common germs.The label should read “NSF 53” or “NSF 58” or contain the words “cyst removal” or “cyst reduction”. If these words are present it means the filter can remove Naegleria. Filter labels that read “absolute pore size of 1 micron or smaller” are also effective at removing Naegleria.
      For more information on the CDC’s recommendations on nasal rinsing as it relates to Brain Eating Amoeba, see here:

      I hope this information is helpful, Alan. Have a lovely day!

  7. I used my Tap water for a nasal sinus irrigation about thirteen days ago in Orlando FL Orange County, I started getting a headache and are freaked out that I may have gotten this amoeba since I researched it, probably over reacting but I am still terrified. Any thoughts.

    • Good morning Mark,
      Sounds like you’ve had a scary day! Whatever comfort it may be, infections using city-treated water are considered very rare.
      The CDC recommends, “To make your water safe for sinus rinsing and ritual nasal rinsing, it is safest to use boiled [for one minute and left to cool], sterile [purchased water marked sterile or distilled], or filtered water [with the filter labelled “NSF 53” or “NSF 58”].”
      You can find specific instructions here:
      However rare, infections from sinus rinsing are technically possible. If your symptoms match those mentioned in the blog post, or if you are at all concerned, my only advice is to seek medical attention. I am not a doctor and cannot give medical advice.
      If you are concerned, seek medical help.
      In the future, please only use properly sterilized water for nasal rinsing.

  8. Yesterday i was fishing a warm, slow moving, shallow river in central florida, and while i was reeling my line in tiny droplets of water flew off the line and went into my right nostril and i instinctively sucked them in, now mind you they were so small i only felt them for an instant, but now i’m super paranoid! Am i likley to develope pam or is infection rare even if a little but of water makes it into the nose?

    • Hi Greg,
      I am not a medical professional, so before I answer I would like to strongly encourage you to see a doctor if you are at all concerned that you have been infected with Naegleria fowleri. As stated in the blog post, the only known survivors of this condition sought professional treatment as soon as symptoms were noticed.
      According to the CDC, “Recreational water-associated infections occur most often in July, August, and September, when temperatures are high for prolonged periods of time, causing water temperatures to rise and water levels to decrease.”
      It has been pretty warm, even for Central Florida, this June so I do understand your concern. However, science tells us that infection is exceedingly rare under normal circumstances and you only described having a teeny amount of water in your nose. Known infections indicate that digging in the underwater sediments and participating in recreational activities that can cause a generous amount of water to enter the nose, like water skiing and tubing, can put individuals at a higher risk.
      As a person who often fishes, boats, and participates in paddlesports in Central Florida, I understand your concern and paranoia! All I can recommend is learn the symptoms and react quickly if they develop. And, in future, try not to “suck up” bits of water that fly near your nose. 🙂

  9. I was recently in the Pisgah forest of NC and went down this natural water slide (sliding rock) and got water up my nose. The water was cold, 55 degrees. I had water up my nose and blew it out, but it took me a day to get it completely out. It’s now 3 days ago and I’m experiencing some nausea. Could this be something to be concerned about or am I just panicking? I wasn’t sure if the cold water would mean that the water would be free of amoebas. Plus I’m in my mid 40’s so I’m not sure if that makes a difference.
    Any advice is appreciated.
    Thank you

    • Hi Garth,
      I am not a medical doctor and as such, I cannot advise you on what your risk is. I can say that research suggests that risk of infection is much higher when water is consistently above 80F. The risk of anything can never be zero, so, if you are concerned I strongly suggest getting the opinion of a medical professional.
      According to the Center for Disease Control and Prevention (CDC),
      “Infection with Naegleria fowleri is rare. The early symptoms of Naegleria fowleri infection are similar to those caused by other more common illnesses, such as bacterial meningitis . People should seek medical care immediately whenever they develop a sudden onset of fever, headache, stiff neck, and vomiting, particularly if they have been in warm freshwater recently.”

  10. I was swimming about 8 days ago in a non-heated chlorinated pool and got water up my nose. I am not having any symptoms, but still paranoid. What are the chances of contracting from a swimming pool?