miss angle can u tell us about naegleria fowleri...you talk so much about her and i dont know her but i am curious... eye emoji eye emoji
naegleria fowleri is a free living thermophillic amoeba! The genus naegleria is within a superclass (rhizopodea) of other parasitic amoebas (like entamoeba and acanthamoeba) and there's like 50+ identified species within the genus but only n. fowleri causes infection within humans. It engages in facultative parasitism and usually is just feasting on yeasts and bacteria in the wild.
There are three morphological stages in the lice cycle of n. fowleri: trophozoite, flagellate, and cyst. The trophozoite Is the infective and reproductive (via binary fission) form! You may have seen this "scary" image of it floating (heh...) around the web.
Those "eyes" and a "mouth" are actually all mouths! They're food cups, thats their little hands they use to eat bacteria, yeast, and your brain!
The flagellate stage is entered in response to an change in environment (usually ph or ion concentration) .
The cystic form is a protective one, being entered when conditions become unfavorable. Usually things like low temperatures, lack of food sources, or dessication. Upon being reintroduced to an environment deemed favorable (such as the nose of an unlucky victim), they can transform back into a trophozoite.
The amoeba can and has been found anywhere from swimming pools to soil to lakes to sewage, but usually one contracts it from warm freshwater sources. The incubatory period of n. fowleri can be anywhere from 2-15 days, but once it reaches a symptomatic stage, death comes relatively quickly.
Now for my personal favourite part: Pathogenesis of N. Fowleri and Clinical Presentation of PAM!
Upon entering the nasal cavity, N. Fowleri traverses your olfactory nerves and breaches the cribriform plate where it is met with a personal banquet: your brain! Here it begins using its food cups to devour the red and white blood cells and tissues within your brain, and causes severe hemorrhaging and necrosis of the brain. This is PAM (primary amoebic meningoencephalitis, also called naegleriasis) and the mortality rate is ~97%.
At its onset, presentation is most similar to acute bacterial meningitis. You'll have fever, a terrible headache, vomiting, and (in some cases) your sense of smell and taste may be affected due to the amoebae damaging your olfactory nerves. Within about a week, you will have most likely died, seeing as only 4 of the 148 infected within the US have survived.
As previously stated, detection is difficult. Its usually found by either testing the CSF (cerebral spinal fluid) or through postmortem examination (the autopsy). Trophozoites are often seen in affected tissue (cortical grey matter, olfactory nerves, and anywhere else they ravaged).
As far as treatment is concerned, there's not much in the ways of an actual treatment plan. The FDA has not approved any one specific drug for the treatment of PAM, seeing as there are so few clinical studies on what works. Miltefosine and Amphotericin B are two drugs that may be administered during treatment, but amphotericin is more of a last-resort option due to high renal toxicity.
Currently the virulence factors of N. fowleri and drugs that work against them has yet to be fully understood. As well as why so few people develop naegleriasis, seeing as millions of people are exposed to fresh water sources each year.
You shouldn't really panic about contracting naegleriais, though, seeing as you're more likely to drown or catch some other syndrome out there (e.g, necrotizing fasciitis).
That isn't every single thing about N. Fowleri, but hopefully I gave you some cool new knowledge today! If you're interested in more comprehensive and in-depth information, or if this was prior knowledge to you and you're looking for something more detailed and complex, I recommend these readings:
Naegleria fowleri: Pathogenesis, Diagnosis, and Treatment Options
Naegleria fowleri: Sources of infection, pathophysiology, diagnosis, and management; a review
Successful Treatment of an Adolescent with Naegleria fowleri Primary Amebic Meningoencephalitis
A rare case of survival from primary amebic meningoencephalitis
The immune response to Naegleria fowleri amebae and pathogenesis of infection
Battling brain-eating amoeba: Enigmas surrounding immunity to Naegleria fowleri
