Cestodes

Question 1

What are the characteristics of the cestodes?

Answer 1

Called tapeworms
Hermaphroditic flat segmented worms
Non operculated eggs
No digestive system
Cause disease that is more severe when human becomes the intermediate host
Larvae in tissue are much worse than a tapeworm in gut

Question 2

What are the characteristics of Taenia solium?

Answer 2

Also called pork tapeworm
Humans are the only definitive hosts
Infection by ingestion of cysticercus in undercook pork or by ingestion of eggs in food or water contaminated with human feces

Question 3

What are the diseases caused by Taenia solium?

Answer 3

Cysticercosis most severe when eggs are ingested, bladder worm invades tissues
Neurocysticerosis- most common CNS parasitic disease worldwide causes seizures
DX: Xray, CT with calcified cysticerci

Question 4

What are the characteristics of Taenia saginata?

Answer 4

Also called beef tapeworm 
Human is the only definitive host 
Common in the USA
Bladder worm in undercooked beef
Disease:asymptomatic to mild diarrhea
ID: proglottids or eggs in feces

Question 5

What are the characteristics of Diphyllobothrium latum?

Answer 5

Also called fish tapeworm
Ingested sparganum larva attaches to intestinal wall
Decelops proglottids and strobila up to 10 m
Infection by ingestion of pond water or raw frogs
Disease: mild discomfort, pernicious anemia, sparganosis
ID: thin wall operculated eggs with apopercular knob in feces, proglottids feces
Sparagonosis-detect motile echogenic mass

Question 6

What are the different Echinococcus ?

Answer 6

Echinococcus granulosus- sheep raising areas, humans ingest egg in dog feces
Echinococcus multilocularis- Rural areas with mice, midwest USA
Cause Hydatid disease

Question 7

What are characteristics of Hydatid disease?

Answer 7

Casoni skin test- hypersensitivity to hydatid fluid

Abdominal swelling produced by large cyst

Question 8

What are the characteristics of Hymenolepsis nana?

Answer 8

Also called Dwarf tapeworm
Most common tapeworm infection in the USA
Develops from ingestion of eggs from mouse, rat or human feces
Ingestion of grain infested with beetles infected by tapeworm
Autoinfection is a feature
Disease: Diarrhea develop when the worm burden is heavy
ID: eggs in feces

Question 9

What are the characteristics of Dipylidium caninum?

Answer 9

Worlwide distribution 
Ingestion of fleas containing larvae
Disease: asymptomatic to mild diarrhea
ID: egg packets with 8-15 eggs
Produce highly mobile proglottid