STEP 1 Protozoa 1 Flashcards
Name 3 protozoa GI infections STEP 1 cares about
- Giardia lamblia
- Entamoeba histolytica
- Cryptosporidium
Giardia causes giardiasis…how does that look exactly? Think poop
Bloating and flatulence.
Foul-smelling, fatty diarrhea…I love my life right now
Who gets Giardia?
How to remember the poop associated with Giardia?
Hikers and campers who do not clean their water.
“Ghirardelli chocolates for fatty poops”
Transmission of giardia?
Cysts in water
How to diagnose giardiasis?
Trophozoites or cysts in stool
How to treat giardiasis?
Metronidazole
What does Entamoeba histolytica cause?
Amebiasis
Clinical presentation of Amebiasis?
- stool
- does an abscess occur? where?
- Pain? location?
- Bloody stool (dysentery)
- Liver and colon abscess…“anchovy paste” exudate for the liver bit
- RUQ pain
What does histology show with amebiasis?
**“Flask-shaped ulcer” if submucosal abscess of colon ruptures
How is amebiasis transmitted?
Cysts in water
Diagnosis of amebiasis? 2
- Serology and/or trophozites (with RBCs in the cytoplasm)
2. Cysts in the stool
Treatment of amebiasis:
Symptomatic and asymptomatic
Symptomatic: Metronidazole
Asymptomatic cyst passer: Iodoquinol
What does cryptosporidium cause in immunocompromised patients? In immunocompetent patients?
Severe diarrhea in AIDS patients…Milwaukee
Mild, watery diarrhea in immunocompetent patients
How is cryptosporidium transmitted?
How is cryptosporidium diagnosed?
Oocysts in water.
Oocysts on acid-fast stain
How to treat cryptosporidium?
Nitazoxanide in immunocompetent (or immunocompromised) hosts
Toxoplasma gondii causes two types of infection:
Acquired or congenital
What does acquired Toxoplasmosis look like on CT/MRI? In which patient population is Toxo prevalent?
Brain abscess in HIV patients.
Looks like “ring-enhancing brain lesions”
What is the classic triad of congenital toxo?
- Chorioretinitis*
- Hydrocephalus
- Diffuse intracranial calcifications
*The chorioretinitis may present as blurry vision, detached retina, or glaucoma
Transmission of toxo? 3
- Cysts in meat
- Oocysts in cat feces
- Transplacental transmission
For fear of toxo, pregnant women should avoid which animal and their poop?
Cats and cat poop
Diagnosis of toxo? 3
- Serology
- Biopsy (looking for tachyzoites–crescent shaped (they mean trophozoite)
- Toxo PCR via LP
How to treat Toxo? 3
- Sulfadiazine
- Pyrimethamine (which cause bone marrow suppression)
- Leucovorin** (not in STEP 1 but used to treat the bone marrow suppression)
Naegleria fowleri causes what?
Rapidly fatal meningoencephalitis
Naegleria transmission
Swimming in FRESHWATER lakes and streams.
Enters via the CRIBRIFORM plate
Naegleria diagnosis?
Ameobas in the spinal fluid
Treatment for naegleria? Prognosis?
Prognosis is not good. Very few reported survivors of a naegleria infection. Best treatment at the moment is Amphotericin B
Trypanosoma brucei is the causative agent of…?
African sleeping sickness
Clinical presentation of Trypanosoma infection
- Enlarged lymph nodes
- Recurring fever–due to antigenic variation (**differentiate from malaria)
- Somnolence
- Coma
Trypanosoma transmission
Tsetse fly…painful bite
Trypanosoma diagnosis
Blood smear
Trypanosoma treatment: 2
Which for blood-borne
*Which for CNS penetration
*If you miss #2 go slap your face
- Suramin–blood borne
2. Melarsoprol–CNS
Two types of Trypanosoma brucei?
**How to treat them? not on STEP 1
- T. b. rhodesiense (suramin, melarsoprol)
- T. b. gambiense (pentamidine, eflornithine)
* *My point here is to show that suramin and melarsoprol only work on rhodesiense
