intestinal protozoa

Question 0

amebiasis & amebic liver abscess

Answer 0

• caused by entamoeba histolytica
• amebic trophozoites and cysts from infected human’s feces –> contaminates water, food, fingers. the trophozoites don’t survive long in stomach. INGESTION -> stomach -> cysts transverse to CECUM /LI –> release LYTIC protein that kills mucosal cells and cause ULCERATING DZ (“flasks/bottleneck”)–> 1. may resemble colon ca (“napkin ring constriction”), 2. submucosal vein –> liver (“ANCHOVY PASTE”: brown filled expanding necrotic cavity -> may rupture)
• > if rupture -> perineum, lungs, heart, etc…RARELY BRAIN.

SX: ranges from asx to BLOODY DIARRHEA. SEVERE RUQ PAIN, LOW FEVER, WEIGHT LOSS. DX BY RADIOLOIC/U.S.

Question 1

what are the 3 groups of intestinal protozoa?

Answer 1

1. amebiasis (& amebic liver abscess)
2. giardiasis
3. chronic diarrhea in immunocompromised hosts:
   
   1. cryptosporidiosis
   2. cyclospora cayetanensis
   3. isospora belli
   4. microsporidia

Question 2

giardiasis

Answer 2

• caused by giardia lamblia that’s spread by ingesting food/whater contaminated with human/animal feces. COMMUNICABLE DZ.
• cysts survive in stomach and release trophozoites in SI. trophozoites is active, causes dz in intestines by attaching to MICROVILLI and reproduce with min. mucosal changes.
• kids: MALAABSP, WEIGHT LOSS, RETARDED GROWTH IF CHRONIC.
• ABD CRAMPING, DIARRHEA (kids susceptible)

Question 3

chronic diarrhea in IC host

Answer 3

• cryptosporidiosis caused by cryptosporidium parvum.
  -ingest crypotosporidium oocytes which are shed in feces.
  unlike toxoplasma and other coccidia, crypt. remains in EC (from stomach to rectum)and forms progenies that also attach to epithelium
  -causes CHRONIC ACTIVE COLITIS (years) in IC ppl, may contribute to death. DIARRHEA, CRAMPY ABD PAIN, LOW FEVER
  -resolves in good immune ppl

Question 4

VAGINAL PROTOZOA

Answer 4

trichomonas vaginalis