Exam II - Fasciolidae Flashcards Preview

RUSVM Parasitology > Exam II - Fasciolidae > Flashcards

Flashcards in Exam II - Fasciolidae Deck (25)
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1
Q

Fasciola hepatica belongs to which taxonomic group?

A

Trematodes

2
Q

For trematodes, what do we always know about the intermediate host?

A

The intermediate host is always a snail

3
Q

For trematodes, what do we always know about the diagnostic stage?

A

The diagnostic stage is always an operculated egg

4
Q

What is the common name for Fasciola hepatica?

A

liver fluke

5
Q

What is/are the final host(s) for Fasciola hepatica? Intermediate hosts?

A

Final hosts - cattle, sheep, goats, and other ruminants and humans

Intermediate hosts - snails

6
Q

Describe the appearance of the Fasciola hepatica adult

A

Adults are 3 cm, leaf shaped, brownish, broader anterior than posterior, oral and ventral suckers, suticle within spines

7
Q

Describe the Fasciola hepatica egg

A

This is one of the largest eggs you’ll encounter in feces.

Eggs are 130 um, yellow brown, with a distinct operculum

8
Q

What is the infective stage for Fasciola hepatica?

A

metacercariae

9
Q

What is significant about Fasciola hepatica eggs passed in feces?

A

They are unembryonated

10
Q

What is the PPP for Fasciola hepatica?

A

2-3 months

11
Q

What is/are the site(s) of infection for Fasciola hepatica?

A

bile ducts of the liver

12
Q

Describe any pathogenesis associated with Fasciola hepatica

A

Immature flukes migrate and feed; fibrosis replaces necrotic tracts

Adults consume blood, irritate host, cause “pipestem liver” (shown in photo below)

Chronic fasciolosis associated with mature flukes in bile ducts

13
Q

How would you diagnose Fasciola hepatica?

A

Quantitative sedimentation, ELISA bulk milk, elevated globulin

14
Q

Treatment & prevention options for Fasciola hepatica?

A

flukicides are available; snail control & management (not really feasible)

15
Q

What is the common name for Fascioloides magna?

A

deer fluke, large American liver fluke

16
Q

What is/are the host(s) for Fascioloides magna?

A

Definitive hosts are deer.

Dead-end hosts include cattle, moose, sika deer, and bison

Aberrant hosts include sheet, goats, and roe deer.

Intermediate hosts are aquatic snails

17
Q

Decribe the appearance of the Fascioloides magna adults

A

Adults are 10 cm, large oval fluke, thick & flesh covered, no anterior core.

18
Q

Describe the appearance of Fascioloides magna eggs

A

Eggsa re 130 um, yellow brown, with a distinct opeculum

19
Q

Describe the general life cycle of Fascioloides magna, compared to Fasciola hepatica

A

Similar to F. hepatica, but juvenile flukes wander aimlessly, fucking things up in the liver tissue

20
Q

Describe the life cycle of Fascioloides magna in the definitive host

A

cyst forms around fluke, develops to adult, which lay eggs

21
Q

Describe the life cycle of Fascioloides magna in the dead-end host

A

cyst encapsulates fluke in liver, never patent

22
Q

Describe the life cycle of Fascioloides magna in the aberrant host

A

fluke migrates, no cyst forms, animal dies before patency

23
Q

What is/are the site(s) of infection for Fascioloides magna?

A

liver

24
Q

Describe any pathogenesis associated with Fascioloides magna

A

In deer & cattle: parasite encapsulated by host minimizes clinical effects

In sheep and goats: continuous migration of immature flukes results in death before patent infection

25
Q

How would you diagnose Fascioloides magna?

A

Fluke eggs are not seen in dead-end and aberrant hosts, but f_ecal sedimentation will show eggs in definitive hosts_

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