Trematodes Flashcards
a. DH ruminants, pigs, horses, wildlife; IH lymnaeid snails
b. Adult site in DH: bile ducts, liver
c. Metacercariae site: vegetation
d. Eggs operculated, oval, yellowish; Adult has cephalic cone and shoulder
Fasciola hepatica
a. DH primarily cervids; IH lymnaeid snails, AH cattle, swine, equine, moose, llama
b. Adult site in DH: bile ducts, liver
c. Metacercariae site: vegetation
d. Sheep/goats aberrant host, never matures and massive damage done by never ending migration
e. Cervids: thin cysts, connect to bile duct; AH: thick cyst, doesn’t connect to bile duct, eggs not shed (dead end host)
f. Eggs operculated, oval, yellow; Adults very large, no cone/shoulder
Fasciolodies magna
a. DH cattle, goats, sheep; IH aquatic snail
b. Metacercariae site: vegetation
c. Adult site in DH: rumen and reticulum
d. Eggs operculated, oval; Adults are small, stubby, and pear shaped
Paramphistomum spp
a. DH sheep, cattle, goats; 1st IH land snail; 2nd IH metacercariae in ants
b. Adult site in DH: liver, gall bladder, bile ducts
c. Eggs brown, oval, operculated, embryonated; Adults flat, lancet-shaped
d. Fecal sedimentation preferred but can sometimes be found on float
e. Rare in humans, can occur if the ant is eaten
Dicrocoelium dendriticum
a. P. concinnum, P. fastosum, P. illiciens
b. DH felids; 1st IH land snail; 2nd IH isopods (pill bugs); 3rd IH lizards, toads, geckos
c. Adult site in DH: bile & pancreatic ducts, gall bladder
d. Lizard poisoning
e. Eggs oval, brown, operculated, contain miracidia; Adults small, brown
f. Fecal sedimentation preferred but can sometimes be found on float
Platynosomum spp
a. DH raccoon, mink, canids, felids, piscivorous birds/mammals, rarely humans; 1st IH aquatic snail; 2nd IH salmonids
b. Adult site in DH: SI; 2nd IH site: kidneys, muscle, fins, other organs
c. Salmon poisoning – neorickettsai helminthoeca
d. Eggs oval, yellow to light brown, indistinct operculum; Adults .5-2mm, ventral sucker, spiny tegument
Nanophyetus salmincola
a. DH canids, felids, swine, muskrats, mink, carnivores, rarely humans; 1st IH aquatic snail; 2nd IH crayfish; PH rodents
b. Adult site in DH: lung parenchyma
c. Eggs thick-shelled, yellow-brown, distinct operculum; Adults reddish brown, 6-12mm
d. Fecal sedimentation preferred but can sometimes be found on float
Paragonimum kellicotti
a. DH felids, canids, carnivores; 1st IH aquatic snail; 2nd IH tadpoles; PH frogs, snakes, mice, mammals
b. Adult site in DH: SI, mammary glands in lactating cats
c. Eggs operculated; Adults 2.5-4mm
Alaria spp
a. DH bats; 1st IH aquatic snail; 2nd IH aquatic insects
b. Reservoir for neorickettsia risticii (agent of Potomac horse fever)
Acanthatrium oregonense
a. DH raccoons, canids, bobcats, nutria, other mammals; lymnaeid snails
b. Adult site in DH: hepatic portal and mesenteric veins
c. Pathology due to eggs migrating out of veins; Canine schistosomiasis
d. Eggs thin shelled, no spine
e. Fecal sedimentation with saline or eggs will immediately hatch
f. Adults dioecious (different than other trematodes)
g. Swimmers itch in humans
Heterobilharzia maericana
