04 - Giardia

Question 1

Answer 1

Question 2

Answer 2

Question 3

Question 4

(Giardia)

(Location in Hosts)

1. Where do they live?
2. How do they stay there?

Answer 4

1. small intestine
2. adhere to intestinal mucosa

Question 5

(Host Range)

Question 6

(Description of Trophozoites)

1. How many flagella? how arranged?
2. 12-15 X 8-10 microns
3. pyriform (tear drop shaped) - bilaterally symmetrical
4. ventral adhesive disc
5. dorsal surface is convex
6. 2 slender rods… called what?

Answer 6

1. 8; arranged in pairs and 2 median bodies
2. ventrocaudal flagellar grooves (axostyle)

Question 7

(Description of Cyst)

1. 12X6 microns
2. How many nuclei? median bodies? axonemes?

Answer 7

2. 2 to 4, 2 to 4, 1 to 2

Question 8

Giardia

Answer 8

troph on right

cyst on left

Question 9

(Giardia Feeding Habits)

1. How does it attach to host’s gut epithelium?
2. Feeds primarily how?
3. Obtains nutrients how?

Answer 9

1. ventral sucker disc
2. pinocytosis (absorbs through surface)
3. contact digestion

Question 10

(Life Cycle)

1. Trophozoites Live where?
2. Dehydration in colon causes trophozoites to do what?
3. then what happens?
4. then what happens?

Answer 10

1. upper small intestine
2. encyst
3. syts pass out in feces and are consumed by another host
4. escyst and begin life cycle anew

Question 11

(Epidemiology)

1. surface water
2. What is the source?
3. Is there an increase in infection with animal contact?
4. Higher incidence associated with day cares
5. human outbreaks associated with failure of water tx/sanitation

Answer 11

2. any critter shedding cysts
3. no (unlike Cryptosporidium)

Question 12

(Pathogenesis)

1. main clinical sign?
2. humans also get what?

Answer 12

1. diarrhea
2. flatulence and abdominal pain

Question 13

(Clinical Singns)

1. Acute Signs?
2. Chronic?

Answer 13

1. foul-smelling diarrhea, mucus/greasy, flatulence, hematochezia (bloody stool) is rare
2. intermittent diarrhea, weight loss, poor growth, poor appetite

Question 14

(Why is Diagnosis Difficult)

1. how big?
2. cysts do not float well in regular salt or sugar solutions… so use what?
3. only shed intermittently… should collect how many succesive defecation?

Answer 14

1. small size
2. ZnSO4 (this will be on exam)
3. 3

Question 15

(Diagnosis)

1. obtain and test fecal samples on how many consectutive defecations/days?
2. Find cyst or trophozoite in feces…

severe diarrhea is mostly what?

direct smear… see what?

3. Cysts best detected how?
4. stain with what to better visualize?

Answer 15

1. 3
2. trophozoite

“falling leaf” motion

3. ZnSO4 centrigual flotation
4. Lugol’s iodine

(other ways to do this are pictured)

Question 16

Question 17

he says that we will be expected to identify Giardia if shown a picture of it…

maybe should run through this guide thing

Question 18

(Prevention and Control)

1. What chemical can kill?
2. UV light inactivates cysts how?

Answer 18

Question 19

(Treatment)

(There are no approved drugs for the treatment of giardiasis)

1-3. What are the three?

Answer 19

1. metronidizole (50% efficiencty)
2. albendazole (safety?)
3. Fenbendazole (what he thinks is best)

Question 20

(Treatment)

(In case of treatment failure)

1. Can extending treatment work?
2. What combination can work?

Answer 20

1. yes
2. fenbendazole + metronidazole

(also third thing)

Question 21

Question 22

Answer 22

A

Question 23

Answer 23

E

Question 24

Answer 24

E