Cestodes (PPT) Part III Flashcards
Common name of Hymenolepis diminuta
Rat tapeworm
Accidental infections to humans of Hymenolepis nana results in
Hymenolepiasis
Life cycle of Hymenolepis nana:
Egg –> Intermediate host –> Cysticeroid –> Adult –> back to egg
The scolex of H. diminuta differs from that of the H. nana is by having a ______ rostellum
rudimentary unarmed rostellum (no hooklets)
Hooklets of the Hymenolopes diminuta
Fan-like arrangement
Diagnosis for Hymenolepid nana:
- Identification of eggs from the stool
- Scolex if the whole worm is expelled
Characteristic of Hymenolepis nana and Hymenolepis diminuta:
Scolex
H. nana: armed rostellum
H. diminuta: unarmed rostellum
Characteristic of Hymenolepis nana and Hymenolepis diminuta:
Eggs
H. nana: with 4 to 8 polar filaments
H. diminuta: without filaments
Characteristic of Hymenolepis nana and Hymenolepis diminuta:
Infective stage
H. nana: Eggs (direct) and Cysticercoid larvae (indirect)
H. diminuta: Cysticercoid larvae
Characteristic of Hymenolepis nana and Hymenolepis diminuta:
Intermediate host:
H. nana: Fleas and flour beetles
H. diminuta: Insects
Characteristic of Hymenolepis nana and Hymenolepis diminuta:
Final host
H. nana: man
H. diminuta: norway rats
Common name for Diphyllobothrium latum
Broad or fish tapeworm
Diphyllobothrium latum may produce in some persons a condition closely resembling _______
pernicious anemia
Diphyllobothrium latum’s scolex is
elongated, spoon shaped characterized by 2 longitudinal grooves
1st and 2nd intermediate host of Diphyllobotrium latum
1st: copepods
2nd: fish
Life cycle of Diphyllobotrium latum:
- Egg/ova
- Coracidium - with cilia
- Cyclops/Copepods (Procercoid larva)
- Freshwater fish (Plerocercoid larva)
Diphyllobothrium latum:
Infective stage to copepods
Coracidium
Diphyllobothrium latum:
Infective stage to fish
Precercoid larva
Diphyllobothrium latum:
Infective stage to humans
Plerocercoid larva
Diagnostic stage of Diphyllobothrium latum
Unembryonated eggs in the feces
Definitive host of Diphyllobothrium latum
Human
Clinical significance of Diphyllobothrium latum
Vitamin B12 deficiency
Diagnosis of Diphyllobothrium latum
- Raw-fish diet and PA is suggestive of diphyllobothriasis
- Finding of characteristic operculated egg or proglottids in
stool or vomited - DFS or Kato Katz technique
Common name of Dipylidium caninum
Double-pored tapeworm
It is the common parasite of dogs and cats worldwide
Dipylidium canicum
Hallmark of the double-pored tapeworm’s hooklets
1-7 rows of rose thorn shaped hooklets
Intermediate hosts of Dipylidium caninum
- Ctenocephalides canis (dog flea)
- Ctenocephalides felis (cat flea)
- Pulex irritans (human flea)
- Trichodectes canis (dog louse)
Causes cystic hydatid cyst disease.
Echinococcus granulosus
Common name of Echinococcus granulosus
Hydatid tapeworm
Definitive host of Hydatid tapeworm
Dogs and other canines
Intermediate host of hydatid tapeworm
Sheep, Goat, Swine, etc
Accidental host of hydatid tapeworm
Humas
Infective stage of hydatid tapeworm
Embryonated egg
Diagnostic stage of hydatid tapeworm:
Hysdatid cysts
Hydatid tapeworm:
____ migrate into the mesenteric venules
Oncosphere
Hydatid tapeworm:
It is formed through central vesiculation
Larval cyst
Hydatid tapeworm:
Found in brood capsules
Protoscolices
When protroscolices &
brood capsules lie free
in cyst, they are
referred to as
Hydatid sand
The most common site and most important site of involvement for hydatid tapeworm:
- Liver (66%)
- Lungs (22%)
- Kidneys (3%)
- Brain and orbit
E. granulosus are called
Unilocular hydatid cyst
E. multilocularis are called
Alveolar cyst