Cestodes Flashcards
What characterizes immature, mature, and gravid proglottids?
Immature- no functional reproductive organs
Mature- functional male and female reproductive organs
Gravid- contains eggs
What is the attachment organ that Cyclophyllideans have? How could it be used to identify the tapeworm?
Scolex.
There may or may not be hooks present on the rostrum.
What characterizes the proglottids of Cyclophyllideans?
1 or 2 sets of reproductive organs
lateral genital pore
NO uterine pore
Why can Cyclophyllidean infections be difficult to diagnose?
Eggs are shed in proglottids and may not appear on a fecal unless the proglottid is broken up
Which metacestode type has a single scolex which is not invaginated? Is it usually found in a vertebrate or invertebrate IH?
cysticercoid
invertebrate
What is a common feature of all Cyclophyllidean larvae?
They are all hexacanth- have six hooks that are visible under a microscope
Which metacestode stage has a single invaginated scolex? Is it usually found in a vertebrate or invertebrate IH?
cysticercus
vertebrate
Which metacestode type has multiple invaginated scolices? Is it usually found in a vertebrate or invertebrate IH?
coenurus
vertebrate
Which metacestode type is a brood capsule with many protoscolices? Can it be surgically removed?
hyatid cyst
unilocular hyatid cysts have a thick wall around them and can be removed in most circumstances
multilocular hyatid cysts have no thick wall and cannot be removed
What is the attachment organ that Pseudophyllideans have?
bothria
What characterizes the proglottids of Pseudophyllideans?
1 set of reproductive organs
central or lateral genital pore
Has uterine pore
Pseudophyllidean eggs look like the eggs of which other parasitic group? What is the main difference?
look like fluke eggs- have an operculum
less dense than fluke eggs and float
How are tapeworms diagnosed?
fecal flotation
What are the hosts of Dipylidium caninum? Where are they found in the definitive host?
Definitive- dogs, cats, humans
found in the small intestine
Intermediate- fleas and the dog louse
Which metacestode stage is in the life cycle of D. caninum?
cysticercoid
What is the infective stage of D. caninum? How is it transmitted?
Transmission occurs when the definitive host ingests a flea or louse that contains the infective stage, ther cysticercoid
What are the signs of D. caninum infection?
Heavy infections can cause constipation, diarrhea, or a pot-bellied appearance
What are the hosts of Anoplocephala perfoliata? Where are they found in the definitive host?
Definitive- horses
found in the small and large intestine but they like the ileocecal valve
Intermediate- mites
What is the metacestode stage found in the lifecycle of A. perfoliata?
cysticercoid
What are the signs of A. perfoliata? What are the sigs of a chronic infection?
Ulcerated lesions and mucosal degeneration at attachment site
predisposes to intussusception (+colic?)
chronic- ill thrift, recurring diarrhea, weight loss
How is A. perfoliata diagnosed?
Fecal floation using sugar solution- difficult, eggs shed sporadically
Indirect or serological ELISA
Necropsy
What are the hosts of Taenia pisiformis? Where are they found in the definitive and intermediate hosts?
Definitive- dogs, foxes
found in the small intestine
Intermediate- rabbits and hares
found in the peritoneal cavitiy, usally attached to abdominal organs
What is the metacestode stage of T. pisiformis?
cysticerus
How is T. pisiformis diagnosed?
fecal floatation
What is the infective stage of T. pisiformis? How is it transmitted?
The definitive host ingests the metacestode stage in the raw meat of the intermediate host
What are the hosts of Spirometra mansonoides? Where are they found in the definitive and 2nd intermediate hosts?
Definitive- felids and canids
found in the small intestine
Intermediate- 1st- copepod
2nd- usually frog, rat, or snake; humans possible
found in muscle
How is S. mansonoides transmitted from the 1st IH to the 2nd IH?
2nd IH ingests 1st IH with procercoid
How is S. mansonoides transmitted from the 2nd IH to the definitive host?
DH ingests the plerocercoid in the 2nd IH’s muscle
What are the signs of S. mansonoides infection? What about in humans?
Usually asymptomatic, can cause vomiting, diarrhea, and weight loss
Can encyst in the eye of humans rather than skeletal muscle
How is S. mansonoides diagnosed?
Fecal examination
Adults can be recovered in vomit or feces
