Fungal and Parasitic Infections

Question 0

Taenia solium

Answer 0

-helminth pathogen
-cestodes=tapeworms
-we ingest undercooked pork that has worm eggs
-humans are definitive host (sex reproduction of tapeworm)
Pathology
-Taeniasis - adult tapeworm in small intestine
-Cysticerosis - larvae develop cysts in eyes, muscles or brain
Treatment
-praziquantel

Question 1

Cryptococcus neoformans

Cryptococcus gatti

Answer 1

-oval, budding yeast
Transmission
-inhalation of yeast cells (bird poop, soil, eucalyptus trees)
Disease
-initially in lungs, then hematogenous spread
-can cause meningitis or rarely brain abscess
Virulence
-polysaccharide capsule
-melanin
Diagnosis
-LFA - lateral flow assay
-“CrAg”
Treatment
-amphotericin B w/ flucytosine, followed by fluconazole

Question 2

Toxoplasma gondii

Answer 2

-protozoan pathogen
-single cell euk
-CATS definitive host (sex reproduction)
-gliding motility
-trophozoite - active form, binary fission in host
-cyst - dormant form for survival
Disease
-taxoplasmosis - 2nd leading cause of death from food-borne illness
Symptoms
-congenital taxoplasmosis - eating undercooked meat during pregnancy extremely bad for fetus/baby
Diagnosis
-PCR amniotic fluid
-mass lesions in brain seen in CT
Treatment
-pyrimethamine and sulphadiazine