flukes

Question 1

all trematodes are hermaphrodties except for what species of fluke?

Answer 1

blood flukes

Question 2

basic life cycle of trematodes (flukes) of domestic animals

Answer 2

eggs release in feces –> miracidia get released from eggs and miracidia enter intermediate host –> asexual repro happens in intermediate host and produce cercariae –> can either develop into infective stage metacercaeriae or encyst as meracercaeiae 2nd intermediate host –>metacercariae inside definitive and develop into adult fluke

Question 3

how are fluke eggs released in the host?

Answer 3

feces

Question 4

what stage in the flukes lifecycle infect enters a snail as a intermediate host?

Answer 4

miracidia

Question 5

fluke eggs develop and hatch in? to release what?

Answer 5

water
-to release miracidia

Question 6

what occurs in the intermediate host of the fluke?

Answer 6

asexual reproduction producing large amounts of cercariae

Question 7

what stage of the fluke lifecycle exists the snail and enters the definitive host?

Answer 7

cercariae

Question 8

what is the infective fluke stage?

Answer 8

metacercariae

Question 9

after cercaeriae exits the snail what are the three possible ways it can infect the definitive host?

Answer 9

-develops into metacercariae encysts on vegetation and gets eaten by definitive host
-encysts as metacercariae in tissues of a 2nd intermediate host and then eaten by definitive host
-actively penetrates the skin of definitive host

Question 10

name of common liver fluke

Answer 10

fasciola hepatica

Question 11

what is the intermediate host of fasciola hepatica?

Answer 11

lymnaeid snails

Question 12

what species of adult fluke colonize bile ducts of mammals?

Answer 12

fasciola hepatica

Question 13

what is transmitted by ingestion of metacercariae on vegetation, adults colonize bile duct of animals

Answer 13

fasciola hepatica

Question 14

what is caused by invasion of liver by young flukes from recent ingested metacercariae

Answer 14

acute fascioliasis

Question 15

what animal is most prone to die from acute fascioliasis?

Answer 15

sheep

Question 16

what is the disease associated with the presence of adult flukes in the bile ducts?

Answer 16

chronic fascioliasis caused by prolong period of ingestion of fasciola hepatica at moderate amounts

Question 17

Dx of fasciola hepatica

Answer 17

fecal ova and parasite prep
ELISA

Question 18

what causes bottle jaw in sheep?

Answer 18

fasciola hepatica

Question 19

what is the north american lung fluke

Answer 19

paragonimus kellicotti

Question 20

what species causes infection by eating crayfish containing encysted metacercariae or by eating animals that have recently fed on crayfish?

Answer 20

paragonimus kellicotti

Question 21

what species of adult fluke infects lungs of cats, dogs, and many wild animals?

Answer 21

paragonimus kellicotti

Question 22

what is the preferred 1st intermediate host of paragonimus kellicotti?

Answer 22

slender walker snail

Question 23

what is the preferred 2nd intermediate host of paragonimus kellicotti?

Answer 23

crayfish
**infection only happens by this

Question 24

what species often occur in pairs in pulmonary cysts

Answer 24

paragonimus kellicotti

Question 25

operculate egg which is released into the respiratory tract and is passed into the environment

Answer 25

paragonimus kellicotti

Question 26

lifecycle of paragonimus kellicotti

Answer 26

operculate egg release into resp tract and passed into environment --> miracidium released from egg into fresh water --> miracidium infects snail --> after asexual repro in snail cercariae are released --> cercaeriae infect crustacean host and encyst as metacercariae --> ingestion of crustacean infects definitive host

Question 27

ciliated miracidium is released from each egg in freshwater

Answer 27

paragonimus kellicotti

Question 28

what young flukes excyst from ingested metacercaria, migrate through gut wall and diaphragm, pair up and mature within lung parenchyma, become encapsulated by granulation tissue and collagen

Answer 28

paragonimiasis caused by paragonimus kellicotti

Question 29

causes pleuritis, pleural effusion, pneumothorax, bronchiectasis, pneumonia, pulmonary hemorrhage

Answer 29

paragonimus kellicotti

Question 30

Dx paragonimiasis

Answer 30

ID unembryonated operculate eggs Lung Xrays

Question 31

what species of fluke causes the disease known as dicrocoeliosis

Answer 31

dicrocoelium dendriticum

Question 32

adults that live in the gallbaldder, bile and pancreatic ducts of mammals (primarily domestic ruminants)

Answer 32

dicrocoelium dendriticum

Question 33

causes infection occurs by eating ants containing encysted metacercariae

Answer 33

dicrocoelium dendriticum

Question 34

what is the ideal habitat for both intermediate hosts of dicrocoelium dendriticum?

Answer 34

dry lowland or mountain pastures

Question 35

what is the 1st intermediate host of dicrocoelium dendriticum

Answer 35

terrestrial snails

Question 36

what is the 2nd intermediate host of dicrocoelium dendriticum

Answer 36

ants

Question 37

infection occurs by eating ants containing encysted metacercariae

Answer 37

dicrocoelium dendriticum

Question 38

what is the main economic impact of dicrocoeliosis

Answer 38

due to rejection of infected livers from slaughtered animals

Question 39

what causes no clinical illness in cattle, lambs, or yearling sheep?

Answer 39

dicrocoelium dendriticium

Question 40

in older sheep, infection causes progressive hepatic cirrhosis, lowered wool production, decreased lactation

Answer 40

dicrocoelium dendriticium

Question 41

Dx of dicrocoeliosis

Answer 41

ID of eggs in feces ELISA

Question 42

no metacercarial stage, the cercariae penetrate skin of host

Answer 42

schistosomatidae

Question 43

sexes are separate in what species?

Answer 43

schistosomatidae

Question 44

adults primarily infect veins of mesenteries of the digestive & urinary tract of mammals and birds

Answer 44

schistosomatidae

Question 45

North American schistosome

Answer 45

heterobilharzia americana

Question 46

most clinical cases in dogs (canine schistosomiasis)

Answer 46

heterobilharzia americana

Question 47

intermediate host of heterobilharzia Americana

Answer 47

lymnaeid snails

Question 48

infection occurs when dogs come in contact with freshwater lakes or streams contaminated with infective cercariae

Answer 48

heterobilharzia americana

Question 49

cercariae penetrate skin, young flukes migrate to liver, mature, then move to mesenteric veins

Answer 49

heterobilharzia americana

Question 50

many eggs become lodged in intestinal wall, liver, and other visceral organs

Answer 50

heterobilharziasis heterobilharizia americana

Question 51

Dx heterobilharziasis

Answer 51

ID of eggs in feces or biopsy samples ELISA & PCR