Trematodes Flashcards
What are the characteristics of trematodes?
Dorsal-ventrally flattened (leaf-like) Oral and ventral suckers Incomplete alimentary tract Hermaphroditic Indirect life cycle
What is the first intermediate host of all flukes?
Freshwater aquatic snails
What is an operculum?
Lid/covering on egg
What is a miracidia?
Free-living ciliated larva
What is a cercariae?
Tadpole like larvae; final and free swimming
What is metacercariae?
Encysted resting stage of trematode
What is the life cycle of a trematode?
Egg in definitive host feces, urine, or sputum
Miracidium develops in egg and released into water
Egg ingested by snail -> sporocyst -> redia
Cercaria leave snail
Cercaria into 2nd IH or on plant
Metacercariae ingested and become adult fluke
How are trematode infections diagnosed?
Fecal sedimentation -> heavy/large eggs
Paragonimus Kellicotti common name?
Lung fluke
Hosts of Paragonimus kellicotti?
Dog, cat, carnivore
Snail (1st IH)
Crayfish (2nd IH)
Identify
Adult- ovoid, reddish brown with spiny tegument
Egg- oval, yellowish brown, distinct operculum, 110um
Paragonium kellicotti
Site of infection of paragonimus kellicotti?
Lung parenchyma
Pathogenesis and lesions of paragonimus kellicotti?
Cysts
Intermittent to severe cough
Dyspnea, pneumothorax, brochiectasis, hemoptysis, pneumonia, death
Dog, cat
Paragonimus kellicotti
What are the methods of diagnosis for paragonimus kellicotti?
Thoracic radiographs -cyst
Fecal sedimentation
Transtracheal wash
Common name of nanophyetus salmincola
Salmon poisoning fluke
Hosts of nanophyetus salmincola?
Dog, cat, mink, raccoon, fish-eating mammals
1st IH: snail
2nd IH: salmonid fish
Adult: ovoid and creamy white up to 2mm
Egg: oval, yellow brown, thick shell, 80um
Nanophyetus salmincola
Site of infection of nanophyetus salmincola?
Small intestine
Pathogenesis of nanophyetus salmincola?
Salmon poisoning -> Neorikettsia helminthoeca
Clinical signs of nanophyetus salmincola?
Enteritis (large numbers)
Salmon poisoning
- fever
- hemorrhagic enteritis
- enlarged lymph node
- vomiting
- diarrhea
- weight loss
- mortality
What is the treatment for Nanophyetus salmincola
Anthelmitics
Tetracycline for rickettsial infection
Common name of Alaria spp?
Intestinal flukes
What is the definitive host of Alaria spp?
Dog, cat fox, mink
What are the intermediate and paratenic hosts of Alaria spp?
1st IH: snail
2nd IH: tadpole
PH: frog, snake, mice, rat, bird, reptile, boar, human
Identify
Adult- pink or brown 10mm
Egg- oval, honey, operculum, 13um
Cat, dog, fox, mink
Alaria spp
Site of infection of Alaria spp?
Adult- small intestine
Immature- lungs
Pathogenesis of Alaria spp?
Migrating mesocerariae may cause pulmonary hemorrhage
Common name of platynosomum fastosum?
Lizard poisoning
DH of platynosmum fastosum?
Cat
IH of platynosomum fastosum?
1st: snail
2nd: crustacean
PH: lizard
Identify
Cat
Adult: 8mm
Egg: oval, brown, medium thick shell, operculum
Platynosomum fastosum
Life cycle of platynosomum fastosum?
Egg to water Snail ingest egg Miracidia to cercariae in snail Cercariae to crustacean Metacercariae encyst in crustacean Lizard eat crustacean Cat eat lizard Fluke to bile duct To adult
PPP of platynosomum fastosum?
3months
Site of infection of platynosomum fastosum
Bile duct
Pathogenesis and clinical signs of platynosomum fastosum
Hyperplastic bile duct
Lizard poisoning- palpable liver, icterus, death
What are the definitive hosts of Fasciola hepatica?
Cattle, sheep, goat, othe ruminants, horses, humans (zoonotic)
Intermediate hosts of Fasciola hepatica ?
Snails
Site of infection of Fasciola hepatica?
Bile duct of liver
What trematode causes
Necrotic tracts in liver
Bile duct inflammation
Anemia, diarrhea, inappetence, bottle jaw, decreased fertility and production.
Fascicles hepatica
What trematode requires condemnation of liver
Fasciola hepatica
How can Fasciola hepatica be diagnosed?
Fecal sedimentation
ELISA
Flukes in liver at necropsy
Elected globulin, albumin and GGT
What are the best treatment and control methods for Fasciola hepatica?
Flukicides
Snail control and management
Draining/fencing off wet pastureland
What is the common name of Fascioloides magna?
Large American liver fluke or deer fluke
What are the definitive hosts of fascioloides magna?
White tailed deer, caribou
Dead end hosts of fascioloides magna?
Cattle, moose, horse, bison, pig
Aberrant host to fascioloides magna?
Sheep, goat, rabbit
What is the intermediate host to fascioloides magna?
Snail
What is the site of infection of fascioloides magna?
Liver
Life cycle of fascioloides magna?
Juvenile fukes wander in liver parenchyma
DH : adult forms fiberous cyst -> eggs passed through pore in cycle
What is the PPP of fascioloides magna?
8months
What is the difference between a dead-end host and aberrant host of Fascioloides magna?
Dead-end: cyst encapsulate adult, but has no pore for eggs to pass through
Aberrant : immature flukes migrate through liver, do not form cyst
In both types of host, the fluke does not reach patency
What is the pathogenesis of Fascioloides magna?
Deer and cattle- encapsulated host has minimal clinical effect
Sheep and goat- migrating in liver causes death before patency
If you suspect Fascioloides magna infection on a sheep or goat, diagnosis can be made by a fecal sedimentation. True or False?
False
Sheep and goat is the aberrant host, does not reach patency therefore you would not see eggs in the sedimentation
Diagnosis by necropsy
What are the best methods of treatment and control of Fascioloides magna?
Flukicide against adult and immature flukes
Snail control
Drain off wet pasture
Do not farm deer and livestock together
Paramphistomum spp common name?
Rumen fluke or stomach fluke
Hosts of Paramphistomum spp?
Cattle, sheep, goat, deer, buffalo, antelope
IH: snail
Identify:
Adult: pear shaped, light red, ventral sucker at posterior end
Egg: operculum 130-180um
Paramphistomum spp
What is the predilection site of Paramphistomum spp?
Rumen
PPP of Paramphistomum spp?
7-10wks
What trematode is associated with secondary infections of Clostridium spp?
Heavy infection due to migrating juveniles = enteritis, anorexia, diarrhea, depression, dehydration, anemia, and hemorrhage
Paramphistomum spp
AKA stomach fluke AKA rumen fluke