export_gi protozoans parasites i Flashcards
Four classes of protozoa
Amoeba - pseudopodia
Flagellates
Sporozoans - gliding
Ciliates
Protozoa reproduction
Asexually, via binary fission
Some can reproduce via schizogony (asexually) or sporogoy (sexually)
Protozoa protection
Many produce a cyst form, which prevents damage and aid in transmission
Entamoeba histolytica disease
Amebiasis
Dysentery
Fever is rare
Lifecycle of Entamoeba histolytica
Excretion of cysts, fecal-oral transmission, activates, then three fates
Three fates of the activated Entamoeba histolytica
Remain in lumen
Invade colon wall, then return to lumen
Travels into circulation
Amebiasis transmission (symptomatic vs. asymptomatic)
Symptomatic individuals shed more trophozoite form, so transmission is LOW
Asymptomatic individuals shed more cyst form, so transmission is HIGHER
Amebiasis penetration into intestinal wall
Flasked-shaped lesion
Amebiasis dissemination
Liver abscess
Abdominal pain, fever, elevated WBCs
Amebiasis diagnosis
Stool examination or Ag detection
Biopsy and serology
Giardia lamblia disease
Giardiasis
Diarrhea, NO dysentery
Giardia life cyle
Excretion of cysts, fecal-oral route, excyst in duodenum, binary fission, attach to mucosa of small intestine, NON-INVASIVE
Giardiasis symptoms
Sudden onset
Foul smelling, greasy, floating diarrhea
Cramping, bloating, gas
NO dysentery, no fever
Giardiasis diagnosis
Observing cysts in formed stools or trophozoites in diarrheal stools
Balantidium coli disease
Balantidiasis
Balantidium coli life cycle
Excretion of cysts, fecal-oral, remain in lumen or invade intestinal wall (return to lumen)
–very similar to entamoeba histolytica)
Balantidiasis symptoms
Generally asymptomatic
Chronic can result in alternating diarrhea and constipation
Acute (invasion) results in dysentery
Cryptosporidium parvum disease
Cryptosporidiosis
Cryptosporidiosis life cycle
Excretion of mature oocyst, fecal-oral, sporozoites attach to intestinal epithelium and matures (schizogony), gametogony is produced, produces more oocysts
Cryptosporidiosis symptoms
Profuse, watery diarrhea accompanied by cramping, fatigue, and weight loss
NO blood in stools
Cryptosporidiosis diagnosis
Detection of acid-fast oocyst in stool
Isospora belli life cycle
Excretion of immature oocyst with sporocyst, sporozoites divide and mature in intestinal mucosal cells, gametogomy produces fertilized oocyst
Isospora belli symptoms
Increasingly present in immunocompromised
Fever, diarrhea, weight loss
Severe in AIDS patients
Cyclospora life cycle
Excretion of unsporulated oocyst, environmental contamination, sporulation occurs in the environment, ingestion, reproduction, produce unsporulated oocyst
Cyclospora diagnosis
Fluorescent under UV light
Cyclospora symptoms
Profuse, watery diarrhea
Cramping, fatigue, weight loss
Prolonged (weeks)
Severe in AIDS patients
Microsporidia disease
Microsporidiosis
Microsporidia features
Obligate intracellular parasites
Primitive
Spore-forming
Intestinal disease or dissemination
Microsporidia intestinal symptoms
Chronic, debilitating diarrhea, anorexia, weight loss
Microsporidia disseminated symptoms
Keratoconjunctivitis
Can be involved in any organ system
