VI- GI Protozoa Flashcards
amebiasis etiology
aka amebic dysentery
from entamoeba histolytica (cyst form)
fecal oral in food/water
travelers
amebiasis presentations
- mostly asymptomatic if stay in lumen of intestine, shed cysts
- intestinal dz if invade colon tissue aka dysentery, fever rare, shed trophs (less infectious)
- extraintestinal if get into circulation, esp hepatic problems
entamoeba histolytica histology
-flask shaped lesions in intestinal wall by trophozoites
entamoeba histolytica diagnosis
- stool exam or antigen detection if intestinal
- biopsy and serology if extraintestinal
giardiasis etiology
giardia lamblia- flagellated
fecal contaminated water, daycares with cysts
-kids in summer and care givers
giardiasis pathology
attach to small intestine wall NOT invade tissue
giardia histology
trophozoite form = teardrop shaped with suction cup/vental disk for adherence, 2 nuclei
look like stingrays
giardia presentation
sudden onset of:
foul smelling greasy stools bc passing a lot of fat + other non specific
NO BLOOD since no tissue invasion
if turns chronic risk malnutrition
giardia diagnosis
observe cysts or trophs in stool
-fecal antigen detection newer
balantidiasis etiology
balantidium coli - ciliated
fecal oral associated with pigs
very rare
balantidiasis presentation
- usually asymp
- chronic - diarrhea or constipation
- acute invasion- dysentery
cryptosporidiosis etiology
cryptosporidium parvum
-replicate within intestinal epithelial cells, not making lesions/invasive
associated with cow manuer, daycares, pools/lakes
cryptosporidiosis histology
oocyst (from sexual reprod instead of asex) on modified acid fast stain
cryptosporidiosis presentation
watery diarrhea no blood
-kids in summer, HIV/AIDS high risk
cyclosporiasis etiology
cyclospora cayetanensis
-associate with food borne outbreaks fresh fruits and veggies RASPBERRIES
cyclosporiasis histology
acid fast oocysts + fluorescent under UV light (differentiate b/t cryptosporidium)
cyclosporiasis presentation
watery profuse diarrhea
-cramping, fatigue, weight loss
AIDS high risk
isosporiasis etiology
from isospora/cystoisospora belli
isospora histology
enlongated shape on acid fast
fluorescent under UV
isosporiasis presentation
fever + watery diarrhea + weight loss
severe in AIDS
microsporidiosis
obligate intracellular parasites
-infect by ingestion of spores
intestinal disease or disseminate esp AIDS
treating protozoa
anti-protozoal compounds target:
-energy production
-nucleic acid syn
-protein syn
-metabolic pathways
nitazoxanide
interfere with energy metabolism of cryptosporidium
sulfonamide
interfere with folic acid syn of cyclospora and isospora
