Giardia Flashcards
true or false: giardia is a protozoa
true
true or false: giardia is non flagellated
false it is flagellated
who found giardia first
antony van leeuwenhoek
what are the names of giardia intestinalis
G. lamblia or G. duodenalis
true or false: giardia infects the intestine
true
what does giardia cause
diarrhea
what is the most common enteropathogen worldwide
giardia
true or false: giardia is not a fatal infection
true but it does play a role in millions of deaths yearly
-due to the diarrhea
g muris infects what
rodents
g agilis infects what
amphibians
g ardae infects what
great blue heronw
hat does g microti infect
voles
what does g lamblia infect
humans
what does giardia infect
the upper part of the intestine
what is the type of life cycle of giardia
direct
which part of the infectious cycle is infectuous in giardia
cyst
giardia can survive in water at 4 degrees for how long?
3 months
how many cysts are sufficient to infect humans for giardia
10
About ….. of people in developed countries have had giardiasis
1/3
giardia affects how % of adults and kids
2% of adults and 6-8% of kids
which is the most common commonly diagnosed intestinal parasite in us and canada
giardia
how many cases per year in the usa but what is the incidence
-20 000 cases/year
-2 million
giardia is fatal for who
immunocompromised people
-hiv, transplant peeps, old and kids
what is the prevalence of giardia acute infection
20-30%
where is giardia mostly found
Russia, E. Europe, Turkey, SE Asia, Central America, Sub-Saharan Africa
giardia cyst is resistant to what?
chlorine
giardia cyst is not resistant to what
freezing
what does the giardia cyst dimensions
6-10 u and is elliptically shaped
the giardia cyst wall is composed of what
fibrous components containing polymers of galactosamine and proteins
what does induce the encystation process for giardia
stomach acids
biological features of giardia
- Two nuclei (lack nucleoli)
-has a ventral disk - Absence of functional mitochondria
- Lack peroxisomes
- Altered Golgi apparatus
- Dependant on anaerobic respiration
giardia: after infestion of the cyst what happens….
-two trophozoites emerge in the duodenum and attch to the host small intestinal mucosa
how do giardia multiply
binary fission in the lumen of the intestine
-they colonize the small bowel
in giardia: some of the tropozoite encysts and are released how?
fecal materials
how many pairs of flagella in giardia and where are they from
-four pairs of flagella
-originate from the basal bodies located near the nucleus
what is unique to giardia cells
median body
in giardia: virus and bacteria are found where?
in the cytoplasm, they are endosybionts
what is the ventral disk made of
complex microtubules and fibrous structures
-structure is rich in tubulin, termed giardin
what is the role of the ventral disck in giardia
serves as organelles of attachment
what have been used to study giardia in humans
mice and giardia muris
-ther gerbil g lamblia model has been used to study the epidemiology and pathology of the disease
mode of transmission giardia
-drinking contaminated water
-contaminated rivers, lakes etc and it is known as beaver fever
-eating contaminated food
-oerson to person contact
true or false: giardia lamblia infects a wide range of mammals which acts as a reservoir
yeah like cattle
an infected person with cysts sheds how many a day
1 billion per day
in usa: how many cysts a day in waters
-10,000 – 100,000 cysts/litre in untreated sewage
-10 – 100 cysts/litre in treated sewage
-10 cyst/litre in surface water and even in tap water.
true or false: 70% of infected peeps with giardia are unaware
false, it is 90%
symtoms of giardia appear when ? and lasts for how long
6-15 days after infection and can last for 2-6 weekswh
what are the most common symptoms of giardia
-diarrhea 96%
-weakness 72%
-loss of apetite and weight loss
50%
what are two complications of giardia
malabsorbtion and dehydratation
giardia can be asymptomatic or the cause of what?
of a severe enteropathy with malabsorbtion
giardia: pathology in the small bowel can be evaluated by what?
measuring the villus to crypt ratio
during the acute phase of the infection of giardia: there is a decrease of what and an increase in what
-Decrease of the height of the villi.
-Increase in the height of the crypt.
giardiasis can be acute and…. or …
acute and self limiting or chronic
when does malabsorbtion happen in giardiasis
-happens during the acute phase of the infection
-disapears after the elimination of the tropozoite from the small intestine
what are the 3 distinct phases in the life cycle of giardia
- A latent period
- An acute phase
- An elimination phase
innate immunity: giardiasis
- Presence of mucus in the
small intestine acts as a
barrier to the invasion of
mucosal tissue. - Normal human milk can kill
Giardia trophozoites.
adaptive immunity giardia:
- Both the humoral and cell-mediated immune responses are playing a role.
- A local inflammatory reaction develops in the small intestinal mucosa.
- The number of plasma cells present in the crypt increases. They are producing mainly IgA antibodies.
which antibodies are the most common in giardiasis
igm and iga are prominant
in giardiasis: igm plasma cells are prominant during when
in the early phase of the infection
in giardiasis: iga plasma cells are prominent when
during the acute phase of the infection
in giardiasis: circulating antibodies are found in the blood but are …..
not useful for protection nor diagnosis
diagnosis giardia
- ELISA
- Stool examination for trophozoites and cysts (usually 3 samples)
- PCR: detection of different isolates
treatment for giardiasis:
-metronidazole: fucks u up
-tinidazole: fucks u up
-ornidazole: fucks u up
-quinacrine: nausea and vomitting
-furazolidone: nausea and vomitting
-paromomycin: nephrotocixity
matronidazole:
-Selectively binds to and damages DNA in anaerobic protozoa: Giardia, Ameba, Trichomonas vaginalis
-Highly active against anaerobic gram-negative bacteria
Bacteroides fragilis, Clostirdium difficile, Helicobacter pylori
-Inhibits aldehyde dehydrogenase, which breaks down alcohol.
