Carol writes:

My Dx: Rule our Naegleri fowleri “brain eating” Ameba

Dr. Wink writes:

I am guessing that the tragic case of the 12-year-old boy with meningoencephalitis in summer was primary amebic encephalitis. If I am right, I will be shattering my previous one-in-a-row record! I hope to keep this streak going. I favor Naegleria over Acanthamoeba, but I’m not sure why. (P.S., I like the commercials and I am enjoying my Curiosity Stream, which I would not have known about without you.)

Wink Weinberg


Patricia writes:

Amoeba infection acquired from swimming in warm water

Shane writes:

G’day Twip Trio,

My guess for Daniel’s case from TWIP #114, is Primary Amoebic Meningoencephalitis, caused by infecting by the brain-eating amoeba Naegleria Fowleri. The young boy most likely contracted the parasite by diving into warm water. The water when forced up the nose can bypass the cribiform plate and deposit the trophozoite stage of the parasite where it can begin feasting on brain tissue. With a fatality rate of over 97%. It does not look good for this patient.

Kind Regards,

Shane from Australia

Iosif writes:

Dear Twip Trio,

I was so excited to hear my professor (Dr. Wiley) finally write into Twip! I had been talking to her about this podcast for some time and had always been encouraging her to write in. I also recommended it to the new 2nd year students at Hofstra SoM as a fun way to study parasites. I just want to thank you all for everything that you do!

P.S. Dr. Griffin asked about my last name: it is Davidov.

Now on to a much more somber note:

When I first was listening to your case I immediately jumped to a previous case (Twip 97) that was presented when I first started to listening to this podcast.  The case was about two different children from Peru with a change in mental status and findings on brain MRI. As a result, I immediately jumped to the worst conclusion for the child in this case.

I would think the likely diagnosis is Naegleria fowleri. This nasty parasite can cause a meningoencephalitis that will lead to death within a few days with a 99% mortality rate. The findings on CSF examination would be similar to a bacterial infection (low glucose, high WBCs), but with no bacterial infection to be cultured anywhere. The infection most likely started when the child was swimming in warm freshwater and accidentally swallowed or aspirated some of the water. The amoeba could make its way through the nasal mucosae, through the cribriform plate and to the brain. Exposure is actually quite common with an estimate that roughly 2 times out of every million results in encephalitis. Treatment is with amphotericin B, but that still only increases survival to at most 5%.

The other diagnoses are other amoeba such as Balamuthia mandrillaris, Acanthomoeba, and Sappinia pedata, but these are much less likely as they would have a  more chronic course.

There have been only 7 surviving cases of naegleriasis in the world. I would prefer it if I was wrong about my diagnosis; if not, I offer my condolences to the family.


Iosif Davidov

Steve writes:


It’s been a while since I’ve written in for one of the case studies primarily because I’ve really wanted to do full differentials on the cases and I find myself derailed in my attempts to do so for one reason or another.

Our 12 year old clearly has primary amoebic meningoencephalitis brought on by an infection by Naegleria fowleri. If I recall correctly from what I read after our hospital received a patient with this infection last year, only two patients in the US have survived in the last 30 years.

Naegleria is an incidental pathogen to humans. Normally it minds it’s own business, hanging out in warm water and soil where it consumes bacteria. But occasionally, we humans disturb the soil at the bottom of a nice warm pool and the trophozoites, if the water gets into the nose, attach to the olfactory epithelia and travels up the olfactory nerve into the brain.  From there it causes meningoencephalitis and death follows in most cases. Amphotericin B is the drug of choice, but even then fatality is greater than 95 percent. Of note, the two survivors in the US were treated experimentally with the drug miltefosine in addition to the standard treatments.

Microscopic examination of the CSF can reveal flagelate amoebae but confirmation requires antigen or PCR testing for Naegleria, something most hospital labs probably cannot do–we had to send CSF to the CDC for confirmation, far too late to do our patient any good, sadly, though our ED physician correctly diagnosed our patient and proceeded accordingly.

Bacterial, viral, and fungal infections of the CNS would be included in my differential, though no bacteria or fungi were seen on smears.

This is unlikely to be GAE brought on by Balmuthia or Acanthamoebae because of the predominant neutrophils and eosinopenia. This is instead consistent with PAM and bacterial meningitis, with the negative Gram stain being the primary distinction between the two, unless of course the lab was, as Daniel seemed to intimate, able to see trophozoites in the CSF.

Well, there you have it. I’m sorry for the family’s loss.

Thanks for another great episode of TWIP. I look forward to seeing if I got this one right.



PS, it’s been consistently hot all summer long in the Eastern Sierra. August has cooled a bit at night, but I cannot wait for autumn to arrive!

Elise writes:

Dear TWIP Trifecta,

How are you? It is much more temperate here in Lower Manhattan than it has been lately (a week ago, I had a huge pile of NYC Air Quality Alerts on my phone and the heat made going outside truly dreadful). I am writing quickly because I am about to travel, so I have not had the time to do a thorough (for me) differential diagnosis.

I believe, sadly, that the 12 year-old patient in TWIP 114 became infected with the Naegleria fowleri amoeba. This is tremendously unfortunate because there is such a poor survival rate for patients. The real tip-off (apart from the fact that I had literally been talking about this amoeba three days ago, so it and the symptoms it triggers were fresh in my mind) came from Dr. Griffin’s emphasis on mentioning that the boy had spent a lot of time swimming in warm fresh water.

The Naegleria fowleri amoeba lives in untreated fresh water and replicates very quickly when the water temperature goes up. It infects the brain when water goes up a person’s nose (which is why people who swim and dive and play in fresh water are susceptible as are people who use “neti pots” for nasal irrigation with untreated water). Because water temperatures have been going up thanks to climate change, the range for the Naegleria fowleri amoeba has been increasing, which may account for Dr. Griffin feeling that it wasn’t crucial to specify the location of the patient and his family.

These infections are easily mistaken for meningitis, because the symptoms are so similar (severe headache, stiff neck, high fevers, lack of responsiveness), and the doctors may have been confused at the boy’s lack of responsiveness to the meningitis treatment. It is apparently tricky to always find the amoeba in the spinal fluid, but that is the best way to make a definitive diagnosis.

The tragic part of this diagnosis is that the prognosis for patients infected with Naegleria fowleri is almost always fatal. There is some success if the infection is caught early with an experimental drug, miltefosine, combined with therapeutic hypothermia  to bring down brain swelling.

I truly hope that I am wrong in this diagnosis because I fear for the worst for this poor child and his family.

Thank you so much as always for your wonderful work.

Best wishes,

Ed writes:

Dear parasitic cognoscenti,

When I was a student focusing on a career in Information Technology, I discovered that I needed some units in lab science. It appeared to me that a course in Microbiology and Human Welfare would be a slam dunk!  

Dr. Akiyama soon provided me with a reality check!  His tests were designed to deliver severe penalties for guessing.

Now that I’m retired from decades of software development, primarily in the area of inkjet graphics, I have discovered your delightful podcasts, and wish to thank you all for renewing my interest in these areas of science.  I recently acquired a copy of the fourth edition of Parasitic Diseases and it is a super reference source.

This is a tragic case, and certainly must be Naegleria fowleri, the brain-eating amoeba.

Acquired by ingesting fluid in the nose while swimming in lakes or streams, and ultimately penetrating the brain. The unfortunate victim develops amebic meningoencephalitis, and unless diagnoses is rapid, probably has little chance of survival. Since 1962-2015 there have been 138 cases with 3 survivors according to a recent CNN article about a patient currently under treatment in Florida.

The drug miltefosine has saved 2 victims in 2013.

It is particularly entertaining to listen to Dr. Despommier share his fly fishing stories, since I do enjoy fly fishing in the Eastern Sierra Nevada near Mammoth Mountain.  The San Joaquin river near Devil’s Postpile and Hot Creek are two of my favorite spots.

The current temperature here in Escondido, California is 86F or 30C, with 53% humidity.  The jury is still out regarding the effects of El Nino, with little evidence of substantial rain, although water restrictions are being relaxed somewhat.   

I love the case format of TWIP, so congratulations on a wonderful podcast!


Paul writes:


A lovely 28 C and sunny here in Indianapolis.

Long time listener 1st time caller…

You mentioned warm water swimming a several times. You also mentioned not a lot of other cases seen. Eosinopenia not sure what that means? Neutrophils and Macrophages would be your primary line of defense, if i guessed correctly. Lots of neutrophils in CBC.

Could this be the rare (138 cases reported since 1962) but dreaded Naegleria fowleri contracted intransally by swimming in warm water lake? If this was a New York or New Jersey case the CDC has to update their map.

Only reference for treatment i saw was iv  and intracisternal / intrathecal amphotericin B treatment. Also added on some dexamethasone for brain swelling?  assume you would have to catch this early before too much brain damage occurs.

A bit of nightmare fuel for all of us listeners who thought we would be safe swimming in a lake.

A tragic rare infection and outcome for your young patient.

I have heard the organism has been found further and further north in US lakes.




Paul then wrote:

I sent in a guess that your case study might be naegleria. If that was a correct guess….

I just read a story about a child from florida that survived after being treated with miltefosine from Profounda pharmaceutical. Dropped temp to 33deg

Induced coma and treated with drugs.

Check out this story:

From News on Flipboard:


Steven writes:

Good morning tremendous TWiP trio,

In the case of the 12 year old male patient, the patient is presenting with classic meningitis symptoms. Stiff neck, decreased CSF glucose, and nothing on the CSF bacterial and AFB cultures leans my diagnosis to a viral meningitis, especially if the differential performed on a CSF cell count cytospin and wright stain showed predominant lymphocytes. This type of infection would show no increase in eosinophil count, but since this fact was worthy of note and due to me writing into a show called this week in parasitism, I am lead to another diagnosis.

I postulate that this patient is presenting with Naegleria fowleri. A nasty protozoa that lives in warm freshwater infecting humans via the nasal pathway. It presents with many if not all the same symptoms of meningitis. There is a chance to see the protozoa on a cytospin, but the amoeba quickly deteriorates. In Dickson’s book, Parasitic Diseases 5th edition, it is stated that there is little clinical experience with this usually fatal disease and that Amphotericin B in the only known therapeutic agent, but oftentimes diagnosis is made too late to be effective.

Great work as always,

Anthony writes:

I happened across a booklet on dog feeding by Leon F. Whitney published in 1960 that contains a section on coprophagy.  The author mentions a related condition, geophagy, in people that can be due to hookworms.  Despite the name, not only dirt but any number of unusual items might be eaten.  An example is given of “a young man who was afflicted with geophagy, which came from a hookworm infestation.  He ate a whole Bible, and was half way through a second when he was treated.”

Should copies of scripture come with the caveat For External Use Only?

BTW, Whitney was a central figure in American Eugenics.

Peter writes:

Hi <substitute standard nomenclature>,

In Ep 113, Vincent decried the lack of non-commercial news. Well, there are probably several, but my favourite (note British/Australian spelling) is It is non-commercial, but some might say ideologically driven. However, you will hear stories you won’t hear elsewhere, and sometimes months before the MSM (main stream media). For example, they were reporting (with some minor inaccuracies) on Flint, Michigan, months before it became the big story it is/was.

Cheers, Pete from Sydney, Australia.

PS: From Google: “A twip (abbreviating “twentieth of a point”, “twentieth of an inch point”, or “twentieth of an Imperial point” [citation needed]) is a typographical measurement, defined as 1/20 of a typographical point.”

Jason writes:

In TWIP Episode 114, at about 7:20, you stated that, in response to the dual needs of diagnostics and containment, Ebola Treatment Units had been built with PCR machines in them.  To the best of my knowledge, this is not the case.

I worked for six months in Liberia, during the Ebola Crisis, and have many close colleagues who worked in Sierra Leone.  I am not personally aware of a single ETU that had it’s own PCR capabilities.   It is possible that the ETU run by the Chinese Government may have had this capacity, but I don’t believe so.

During the Ebola Crisis, PCR samples were transported by Land Rovers, often significant distances over muddy roads. We had an elaborate protocol for labeling and decontaminating the transportation vessel. Towards the end of the crisis the logistics of this became even more complicated, as many of the testing centers closed due to reduced demand, and transport distances became even further.  

The only diagnostic capability that we had in the ETU’s was a point-of-care malaria test, though this was largely pointless as the Hastings Protocol calls for treatment with Coartem regardless.

Anthony writes:

When I was a child in the days of Silent Spring insects were very visible.  At night there’d be galaxies of moths and gnats surrounding eveystreet light.  The same would be true in a lesser way for the bulbs illuminating a porch.  

This no longer is so.  The number of night flying insects has been much less and this year dramatically so.  I keep a vestibule door open during the day to prevent heat buildup in that small space.  It had been important to close the door at night or many moths, gnats and crane flies attracted to the light would need to be chased out in the morning.  This year, nocturnal insect visitors have been very few.

That the insect vanishing point is not just a quirk of my street seems to be confirmed by the observations of a cross-country trucker who found his way to Jersey City Free Books.  He related how his father had had the same occupation.  Back in the ’70s, the then young son’s chore on his father’s return was to hose off the truck grill.  From impact with the swarms of flying insects, there’d be a thick buildup there.  The trucker went on to say how when he gets back West now there’ll be just a few dead bugs here and there.

The curious thing is that mosquitoes seem to be doing very well.  Indeed, the buckets of water that result from my cleaning fish tank filters need to be quickly dumped or hordes of mosquito larvae will result.


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