Giardia Flashcards
Giardia genus habitat and transmission.
Giardia resides in the intestine of infected animals or in infected water sources.
Transmitted when people drink infected water sources that have not been properly filtered to remove the cysts form of the trophozoites.
Technically fecal-oral.
What is the species of Giardia we discussed?
Giardia morphology.
Giardia lamblia
There are two morphological forms:
Trophozoites:
- 8-14 uM. Kite shaped
- two nuclei
- 4 pairs (8 total) flagella, lateral, ventral, dorsal, and posterior.
- Suction disk
Cyst form
- 6 uM
- spherical, thick walled
- 4 nuclei
Giardiasis clinical presentation
Frequently seen in campers that drank contaminated water.
Is possible to be asymptomatic
The protozoan adheres to the intestinal wall but doesn’t pentrate
Inhibits lipid absorption, causing fatty diarrhea (not bloody) steatorrhea
It also causes bloating, flatulence, and excessively foul smelling steatorrhea.
It somehow impairs IgA excretion, causing the above symptoms.
The impaired lipid absorption can lead to lipid soluble vitamin deficiencies ADEK.
Giardiasis diagnosis
Stool sample examination for trophozoites and cysts. Diagnostic test is called. the “stool O and P test” for ova and parasites.
ELISA stool antigen test.
String test: patient swallows an indigestible string that becomes coated in the trophozoites, then examined.
Giardiasis treatment
Metronidazole.
Tinidazole, or paramycin.
It is not killed by chlorination of water, and must be filtered.
