Seminar 4: Cestodes Flashcards
Cestodes are commonly known as ____
tapeworms
What are the human infecting species of cestodes? List 5
- Echinococcus
- Taenia
- Dipylidium caninum
- Diphyllobothrium latum
- Hymenolepis spp (H. diminuta and H. nana)
which tapeworm is famously associated with bears?
Broad fish tapeworm- infected from eating salmon
What’s the infective stage of H. diminuta?
Cysticerci: in the body cavity of an insect ingested by a rodent or human
What’s the infective stage of H. nana?
An embryonated egg is ingested by humans from contaminated water/ food
This embryonated egg comes out in human feces
What’s the diagnostic stage of H. diminuta?
when the eggs are passed in human feces
What is the diagnostic stage of H. nana?
The embryonated egg in human feces
T/F
Hymenolepis is:
- one of the most prevalent parasitic diseases
- found most commonly in adults
- true: found worldwide
- false: found most commonly in children, esp in areas with little sanitation
Hymenolepis is most often asymptomatic. At what point can it become symptomatic?
Heavy infections may cause symptoms: when there are 10,000 + eggs in stool
T/F
Hymenolepis has a short life cycle, but can use autoinfection
true
How do you diagnose hymenolepis?
Diagnosed 3-4 weeks after initial ingestion: find eggs in stool
Describe the difference between a H. diminuta egg and a H. nana egg
H. diminuta:
- larger (~70micrometers)
- circular
- no polar filaments
H. nana:
- smaller (40-50 micrometers)
- oval
- double-layered shell enclosing filaments
Give some treatment and control measures for Hymenolepiasis
Drugs: praziquantel, niclosamide, nitazoxanide
- test stool 1 month after
- hygiene and education
- pest control
T/F
Hymenolepis cysticercoids can develop in vertebrates, but not invertebrates
false
Can develop in both (developmental plasticity)
- differences in antigenicity
T/F
Hymenolepis has immunomodulatory effects
true
ie. changes body’s immune response
- via sfc proteins and excretory/ secretory products
