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156 SEcTioN ii Microbiology ` microbiology—Parasitology Microbiology ` microbiology—Parasitology

Protozoa—CNS infections
orgaNism Disease traNsmissioN DiagNosis treatmeNt
Toxoplasma Immunocompetent: Cysts in meat (most Serology, biopsy Sulfadiazine +
gondii mononucleosis-like symptoms, common); oocysts (tachyzoite) B pyrimethamine
⊝ heterophile antibody test in cat feces; crosses
Reactivation in AIDS Ž brain placenta (pregnant
abscesses usually seen as women should
multiple ring-enhancing lesions avoid cats)
on MRI A
Congenital toxoplasmosis:
classic triad of chorioretinitis,
hydrocephalus, and intracranial
calcifications
Naegleria fowleri Rapidly fatal meningoencephalitis Swimming in warm Amoebas in CSF C Amphotericin B has
freshwater; enters been effective for a
via cribriform plate few survivors

Trypanosoma African sleeping sickness— Tsetse fly, a painful Trypomastigote in Suramin for blood-
brucei enlarged lymph nodes, recurring bite blood smear D borne disease or
fever (due to antigenic variation), melarsoprol for
somnolence, coma CNS penetration
(“I sure am
mellow when I’m
sleeping”)
A B C D

FAS1_2019_03-Microbiology.indd 156 11/14/19 12:21 PM