Cestodes Flashcards
True or false cestodes are part of the Platyhelminthes clad
True
Define scolex of a cestode
“head” used for attachment
Define proglottids
the individual segments of a cestode
What is a chain of proglottids called
strobili
What are the 9 medically relevant cestodes
- T. solium
- T saginata
- D. latum
- E. granulosus
- E. multilocularis
- H. nana
- H. dimunta
- D. caninum
- Sparganosis
Cysticercosis, echinococcosis, and sparganosis are associated w/ what type parasite
cestodes
Differentiate between a T. solium infection and cysticercosis infection caused by T solium
Etiology:
T. solium- eating pork that has T. solium cyst
Cysticercosis- eating T solium eggs
Symptoms:
T. solium- indegestion and diarrhea
Cysticercosis- cyst location dependent
Dx tool:
T. solium- stool exam
Cysticercosis- calcified cyst on imaging
Prevention:
T. solium- cook pork
Cysticercosis- sanitation
Describe T saginata in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide
Cause: eating undercooked beef
Symptoms: asymptomatic, indigestion, vague abd pain
DX: stool exam
Prevention : cook meat and sanitation
Describe D. latum in terms of distribution, what causes it, symptoms, how to dx, additional treatment besides deworming, and prevention
Distribution: worldwide, prevalent in cool lake regions
Cause: eating raw, undercooked or pickled fish
Symptoms: asymptomatic, B12 def, epigastric/abd pain, nausea
DX: stool exam, w/ wide proglottids
Treatment: supplement B12 prn
Prevention : cook meat properly and sanitation
Describe E. granulosus in terms of distribution, what causes it, symptoms, how to dx, treatment and prevention
Distribution: worldwide, prevalent where sheep are raised
Cause: ingestion of water or vegetation contaminated by eggs or oral-fecal route of eggs from dogs to humans
Symptoms: depends on cyst location, slow growing
DX: imaging of hydatid cyst, aspiration (high risk d/t anaphylaxis)
Treatment: surgical resection or aspiration of cyst then adding formalin
Prevention : education on how tapeworm is transmitted
Describe E. multilocularis in terms of distribution, what causes it, symptoms, how to dx, treatment and prevention
Distribution: Northern latitudes (Canada, N. Japan, Alaska, former USSR, Montana, N. and S Dakota…)
Cause: eggs from infected foxes, dogs, or cats
Symptoms: can mimic liver carcinoma, infection can also spread to lungs and brain
DX: serologic techniques
Treatment: surgical removal of cyst
Prevention: deworming of farm dogs/cats, personal hygiene, and education
Describe H. nana in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: Worldwide, most common tapeworm infection in N. America
Cause: ingestion of contaminated grain/flour from beetles or autoinfection
Symptoms:
- few worms: asymptomatic
- heavy worms: vague, diarrhea, abd pain
DX: stool exam w/ six hooked embryo containing egg
Prevention: sanitation and hygiene
Describe H. diminuta in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide
Cause: ingestion of grain contaminate by rodents or mealworms
Symptoms:
- low/mild worms: asymptomatic
- heavy worms: abd pain, nausea, diarrhea
DX: bile stained egg that lack filaments
Prevention: rodent control where grain is stored
Describe D. caninum in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: worldwide, especially in children near dogs/cats
Cause: dog/cat lick child/human mouth after crushing a flea w/ its mouth
Symptoms:
- low/mild worms: asymptomatic
- heavy worms: abd pain, anal pruritis
DX: stool exam w/ eggs and proglottids
Prevention: deworm dogs and cats
Describe sparganosis in terms of distribution, what causes it, symptoms, how to dx, and prevention
Distribution: Asia in cold water lakes
Cause: ingestion of larval forms of tapeworms either by drinking water w/ crustaceans larval tapeworm or eating raw, amphibians and reptiles
Symptoms: painful, inflamed subcutaneous tissue
DX: surgical biopsy
Prevention: clean water and not eating undercooked amphibians and reptiles
