5. Trematodes Flashcards
Life cycle of trematodes
- miracidium: infective to 1st IH
- sporocyst
- redia
- cercaria: infective to 2nd IH
- metacercaria: infective to DH
AKA trematodes
Flukes
DS for C. sinensis
Ova
Ova with miracidium, large shoulders, operculated, terminal knob
C. sinensis ova
Habitat of C. sinensis in humans
Liver
Large intestinal fluke
Fasciolopsis buski
DS of F. buski
Ova
IS of F. buski
Ova
Ingestion of undercooked fish
C. sinensis
H. heterophyes
M. yokogawa
Ingestion of infected water plants
F. buski
F. hepatica
Ingestion of crab
P. westermanni
Sheep liver fluke
Fasciola hepatica
Differentiate F. hepatica and F. buski based on adult larva
F. hepatica adult larva has shoulders while F. buski adult larva has none
IS of F. hepatica
Ova
DS of F. hepatica
Ova
Fluke where humans are accidental hosts, sheep are the DH
F. hepatica
Von Siebold’s fluke
Heterophyes heterophyes
Heterophid fluke in Africa, the Far East, Near East, Egypt
Heterophyes heterophyes
Flask-shaped ova
H. heterophyes
Ova of H. heterophyes is similar to ova of
C. sinensis
M. yokogawa
Pyriform adult larva
H. heterophyes
Heterophid fluke in the Far East, Europe and Siberia
Metagonimus yokogawa
Oriental lung fluke
Paragonimus westermanni
IS of P. westermanni
Ova
DS of P. westermanni
Ova (stool or sputum)
Ova: oval, undeveloped miracidium, thin shell, operculated with shoulders, thickening at terminal end
P. westermanni
Bladder fluke/Vesical blood fluke
Schistosoma haematobium
IS of Schistosomes
Cercariae
Schistosome ova with large terminal spine
S. haematobium
Adult Schistosome resides in blood vessels around urinary bladder
S. haematobium
IH of Schistosomes
Snails
Oriental blood fluke
Schistosoma japonicum
DS of Schistosomes
Ova
Schistosome ova with small lateral spine
S. japonicum
Adult Schistosome resides in blood vessels around intestinal tract
S. japonicum
S. mansoni
A characteristic irritation of the skin at the site where Schistosomes penetrate
Swimmer’s itch (Schistosome dermatitis)
Manson’s blood fluke
S. mansoni
Schistosome ova with large lateral spine
S. mansoni
Chinese liver fluke
Clonorchis sinensis