Naegleria fowleri, like many other parasites, has a complex life cycle. It has three life stages: cyst, flagellate, and the intermediate trophozoite phase
It is this trophozoite phase that can infect humans. Normally, the amoeba lives in warm bodies of water such as lakes, rivers, and hot springs. (This last locality is the most common in NM). When a swimmer gets contaminated water up their nose, the trophozoite will travel from the nasal cavity along the olfactory nerve into the brain. |
destroyed Brain tissueOnce in the brain, the amoeba, which normally would eat bacteria, begins attacking both blood cells and nervous tissue, causing a massive inflammatory response.
|
It Eats brainsThis inflammatory response increases the intracranial pressure, leading to a presentation very similar to acute meningitis/encephalitis. (Meningoencephalitis)
|
PrognosisUnfortunately, unlike bacterial infections, the amoeba does not respond readily to treatments. This form of meningoencephalitis only has 4 known survivors in North America.
The patient from our case was not one of them. |