Trematodes Clinical Microbiology Review 254
ROUTE OF LOCATION
TREMATODE INFECTION OF ADULT DIAGNOSTIC STAGE OTHER
Fasciolopsis buski
Fasciola hepatica
Clonorchis sinensis
Largest trematode.
Sheep liver fluke.
Chinese liver fluke.
One of the most
frequent infections
seen in Asian
refugees. Egg is one
of smallest passed
by humans.
Ingestion of
metacercariae on
aquatic plants
Ingestion of metacer-
cariae on aquatic plants
Ingestion of metacer-
cariae in raw,
undercooked, dried,
salted, or pickled fish
Duodenum
Bile duct
Bile ducts, gallblad-
der, pancreatic
ducts
Ova in feces. 135 × 80 μm. Yellow-brown. Thin
shell. Small operculum. Granular contents evenly
distributed. Clear zone between shell & yolk.
Similar to F. buski.
Ova in feces. 29 × 16 μm. Bulbous. Opercular
shoulders. Small comma-shaped protuberance
at posterior. Thick shell with tiny spines.
Ciliated miracidium inside.
operculum
thickened rim
around operculum
(called shoulders)
developed
miracidium
small knob
(From Leventhal R, Cheadle RF. Medical Parasitology: A Self-
Instructional Text, 5th ed. Philadelphia: FA Davis; 2002:67.)
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