Protozoa of the Intestinal Tract Flashcards
Entamoeba histolytica
lab tests
Entering the Historical Dig
Flask shaped ulcers along the colon
Bloody stool
Stool O&P (ova and parasite exam) looking for cysts or trophozoites will contain trophozoites that contain endocytosed RBC’s.
Elisa antigen test on stool or serum.
Entamoeba histolytica
2 main life cycle stages
Entering the Historical Dig
- Cyst form is infectious and is ingested from contaminated water. Gay men can get the disease from anal oral transmission.
- Trophozoite** form invades** the colon, spreads via portal circulation into the liver.
Entamoeba histolytica
signs and symptoms
Entering the Historical Dig
- RUQ pain w/ enlarged and tender liver.
- Right lobe is the most commonly involved site of amoebic liver abscesses.
- Puss inside abcess have “anchovy” paste consistency.
- Intestinal amebiasis
- Flask shaped ulcers along the colon.
- Bloody stool
Entamoeba histolytica
Treatment
Entering the Historical Dig
Metronidazole
Can be taken with a lumenal agent like:
Paramycin or Iodoquinol
* DDX Entamoeba which you treat without removing surgically vs. Echinococcus which has a liver mass that you do remove surgically.
Giardia Lambia
lab tests
Giardia Jungle Ride
Foul smelling Steatorrhea (fatty diarrhea)
Stool O&P (ova and parasite exam) looking for cysts or trophozoites show trophozoites that are flagellated with ventral sucking discs.
Elisa antigen test on stool
Deficient in Vit. A,D,E,K
Giardia Lambia
2 main life cycle stages
Giardia Jungle Ride
- Cysts from feces contaminates water, and infects travelers, backpackers, or campers who drink unfiltered or unpurified water.
- Trophozoites attach to but do not invade intestinal walls, so only cause diarrhea.
Giardia Lambia
signs and symptoms
Giardia Jungle Ride
Bloating, flatulence, and foul smelling diarrhea.
Steatorrhea (fatty diarrhea) due to excessive mucous production that impairs the absorption of the intestine (A,D,E,K will be deficient).
Giardia Lambia
Treatment
Giardia Jungle Ride
Metronidazole
Cryptosporidium
lab tests
Tales from the crypt
Unicellular partially acid fast.
Under staining looks like amethyst in water.
Cysts contain 4 motile sporozoites.
Profound watery diarrhea.
Cryptosporidium
2 main life cycle stages
Tales from the crypt
- Oocysts are infectious, released fecally, and absorbed orally. Highly resistant to chlorination, but can be removed via filtration.
- Cysts contain 4 motile sporozoites that will attach to the small intestine wall and cause damage.
Cryptosporidium
signs and symptoms
Tales from the crypt
Profound watery diarrhea
* Most common cause of diarrhea in AIDS patients!
Cryptosporidium
Treatment
Tales from the crypt
- Nitazocanide tx for immunocompetent
- Spiromycin (not FDA approved in US)(a macrolide antibiotic)
- Supportive care
