Giardiasis

Question 1

what are the causative agents of giardiasis?

Answer 1

Giardia duodenalis
Giardia psittaci

Question 2

what species get infected with Giardia duodenalis?

Answer 2

livestock, companion animals, humans

Question 3

what species get infected with Giardia psittaci?

Answer 3

birds

Question 4

what type of protozoan is Giardia and where does it infect?

Answer 4

flagellate protozoan
infect - upper GI tract

Question 5

Is giardia monoxenous or heterozenous?

Answer 5

monoxenous - direct life cycle

Question 6

how do trophozoites divide in Giardia spp.?

Answer 6

binary fission

Question 7

what are the key characteristics of Giardia trophozoites?

Answer 7

pyriform shape - anterior end broad and rounded
concave, ventral adhesive disc
two nuclei
two median (parabasal) bodies
two axostyles
four pairs of flagella

Question 8

what is a key characteristic of the Giardia trophozoite that is unique to the genus?

Answer 8

median bodies

Question 9

what are the key characteristics of Giardia cysts?

Answer 9

thick walleed cyst
contain 4 nuclei when mature
two trophozoites released from cyst
excystation triggered by gastric acid, pancreatic enzymes, and bile salts

Question 10

how many trophozoites are released from a giardia cyst?

Answer 10

2

Question 11

what triggers the excystation of giardia cysts?

Answer 11

gastric acid, pancreatic enzymes, and bile salts

Question 12

how many genetic assemblages does Giardia duodenalis have?

Answer 12

8

Question 13

what are the 8 genetic assemblages of Giardia duodenalis?

Answer 13

A&B - wide range of domestic and wild animals
C&D - dogs and wild canids
E - hoofed stock
F - cats
G - rodents
H - seals

Question 14

how is Giardia duodenalis transmitted?

Answer 14

direct ingestion of fecal Giardia cysts
indirect ingestion of contaminated water, food, transport hosts, infected prey species, or fomites
re-infection from animal fur when they groom

Question 15

what is the prepatent period for Giardia duodenalis in dogs and cats?

Answer 15

dogs - 4-12 days (mean 8 days)
cats - 5-16 days (mean 10 days)

Question 16

Is Giardia more prevalent in puppies or kittens?

Answer 16

puppies

Question 17

what are the major virulence factors of Giardia spp.?

Answer 17

attachment
circumvention of natural factors of intestinal lumen
antigeni variation
alteration of host innate defenses
anti-inflammatory modifications
survival in stomach acid and external environment

Question 18

what is the main factor responsible for immune evasion in Giardia?

Answer 18

variant-specific surface protein (VSP)

Question 19

where is variant-specific surface protein found in giardia?

Answer 19

covers entire surface of cell

Question 20

where do ingested giardia cysts excyst?

Answer 20

duodenum - release two trophozoites

Question 21

where are trophozoites found in dogs and cats?

Answer 21

dogs - duodenum to ileum
cats - jejunum to ileum

Question 22

how do giardia trophozoites attach to the brush border of the villus epithelium?

Answer 22

ventral adhesive disk
surface molecules
network of contractile proteins

Question 23

what are the proposed mechanisms of disease of giardiasis?

Answer 23

apoptosis of enterocytes
loss of epithelial-barrier function
hypersecretion of Cl ions
diffuse microvillus shortening
immune reaction’inhibition of brush-border enzymes and trypsin
interference with bile salt metabolism

Question 24

where is giardiasis most observed?

Answer 24

young animals - illness typically more severe and persistent

Question 25

what are the symptoms of giardiasis in dogs and cats?

Answer 25

intermittent diarrhea or soft stools, ***typically light-colored, mucoid, malodorous***, may contain fats, unthrifty appearance & weight loss, occasional vomiting

Question 26

where is Giardiasis typically a self limiting ilness?

Answer 26

immunocompetent hosts

Question 27

what species is Giardiasis uncommon?

Answer 27

horses

Question 28

what are the symptoms of Giardiasis in ruminants?

Answer 28

diarrhea (pasty to fluid, mucoid), decreased appetite, loss of weight

Question 29

what is seen in cockatiels and buderigars neonates with avian giardiasis?

Answer 29

poor growth and high mortality

Question 30

what type of birds have most clinical cases of Giardiasis?

Answer 30

buderigars and cockatiels

Question 31

what species/host is the most implicated in zoonotic transmission of Giardia duodenalis?

Answer 31

beavers

Question 32

which has a higher prevalence of Giardia duodenalis - shelter dogs and cats or client-owned animals?

Answer 32

shelter dogs and cats

Question 33

what are some clinical suspicious of giardiasis?

Answer 33

-previous history of it in environment -diarrhea unresponsive to antibiotic or coccidiostatic treatment

Question 34

how will a suspected sample of giardiasis be examined under the microscope? (trophozoites and cysts)

Answer 34

-direct saline smear for detection of motile trophozoites -fecal flotation (***zinc sulfate floatation***) with centrifugation for detection of cysts

Question 35

what some fecal immunoassays that can be done to detect giardiasis?

Answer 35

DFA IFD ELISA immunochromatographic assays antigen detection kits

Question 36

when is fecal PCR most used for giardiasis?

Answer 36

identify Giardia duodenalis not normally used to diagnose

Question 37

what type of diagnostics would be done? If positive for Giardiasis what would be prescribed?

Answer 37

zinc sulfate flotation giardia lateral flow immunoassay metronidazole prescribed

Question 38

which solution was used in each picture - same sample? what flotation solution should be used to detect giardia?

Answer 38

1. sheather's sugar solution 2. ***zinc sulfate solution***

Question 39

does the type of flotation solution matter when detecting giardiasis?

Answer 39

YES use zinc sulfate solution

Question 40

In what species is prevention considered impractical since Giardia is so prevalent in the environment?

Answer 40

livestock

Question 41

what are some prevention and control measures for giardiasis?

Answer 41

enforce strict sanitation and good management bird - wire floor cages, raised food and water bowls post - treatment fecal exam colostrum management and adequate nutrition

Question 42

what is the feeding stage and infective stage of Giardia?

Answer 42

feeding - trophozoite infective - cyst

Question 43

what medications can be used for Giardia in dogs and cats?

Answer 43

Febendazole/metronidazole

Question 44

what medications can be used for Giardia in ruminants?

Answer 44

febendazole/albendazole

Question 45

which species with giardia has light-colored, mucoid & malodorous, steatorrhea diarrhea and which has pasty to fluid, mucoid diarrhea?

Answer 45

light-colored, mucoid & malodorous, steatorrhea - dogs and cats pasty to fluid, mucoid - ruminants

Question 46

what effect of Giardia is most responsible for the excess water loss?

Answer 46

Excessive secretion of chloride