Cestodes- Taenia

Question 1

What are the hosts of Taenia saginata (aka beef tapeworm)?

Answer 1

definitive host: humans only

intermediate: host: cattle only

Question 2

What is the cysticercus?

Answer 2

tapeworm stage where the scolex is invaginated inside and where it will evaginate. soybean-like in shape. common to all Taenia species

Question 3

What is particular about the Taenia saginata scolex?

Answer 3

have four suckers and lacks hooks

Question 4

Which organs do the mature proglottids of Taenia saginata have?

Answer 4

both male and female organs

Question 5

How can Taenia saginata gravid proglottids be identified?

Answer 5

have 15 or more branches on each side of the uterus

Question 6

Why are the eggs of Taenia saginata not used for diagnosis?

Answer 6

all eggs of parasites from the Taeniidae family have identical eggs

Question 7

Will Taenia saginata develop if a cow ingests an egg?

Answer 7

yes

Question 8

Will Taenia saginata develop if a cow ingests a cysticercus?

Answer 8

no

Question 9

Will Taenia saginata develop if a human ingests an egg?

Answer 9

no

Question 10

Will Taenia saginata develop if a human ingests a cysticercus?

Answer 10

yes

Question 11

What are the hosts of Taenia solium (aka pork tapeworm of humans)?

Answer 11

definitive host: humans only

intermediate host: pigs only

Question 12

What makes Taenia solium more dangerous than Taenia saginata?

Answer 12

humans can be accidental intermediate hosts

Question 13

What is particular about the Taenia solium scolex?

Answer 13

has 4 suckers and 2 circles of hooks

Question 14

How can Taenia solium gravid proglottids be identified?

Answer 14

have 14 or more branches on each side of the uterus

Question 15

What is the diagnostic stage for Taenia solium?

Answer 15

the gravid proglottids

Question 16

What is cysticercosis?

Answer 16

When humans ingest eggs or become auto-infected. can cause neurocysticercosis (cysticercus infection in the brain) with symptoms of seizures, mental disturbances,
focal neurologic deficits, and signs of space‐occupying intracerebral lesions

Question 17

How can cysticercosis be diagnosed?

Answer 17

need to demonstrate cytircercus in the involved tissue. Taenia solium infection indicates taeniasis, not cysticercosis

Question 18

How can cysticercosis be treated?

Answer 18

a combination of anti-parasitics and anti-inflammatories used. surgery used in case of eye infections, not responsive to drugs, or to reduce brain edema

Question 19

How can the adult Taenia solium worms be treated?

Answer 19

praziquantel. increases the worm’s permeability to calcium ions

Question 20

What are the hosts of Echinococcus granulosa?

Answer 20

definitve host: dogs and other Canidae

intermediate host: sheep + other herbivores, humans

Question 21

Which variety of Echinococcus granulosa infects native Canadian’s?

Answer 21

Echinococcus granulosa var. canadiensis aquired from moose and caribou

Question 22

What is hydatid disease?

Answer 22

aka. echinococcosis. when the juvenile stage of the parasite develops into a large, fluid-filled cyst (hydratid cyst)

Question 23

How can Echinococcus granulosa be distinguished from other tapeworms?

Answer 23

one of the smallest tapeworms. scolex has 4 suckers with hooks. has only scolex, neck, one immature proglottid, one mature proglottid, and one gravid proglottid at a time.
egg cannot be distinguished from Taenia species

Question 24

Which stage of Echinococcus species cause echinococcosis?

Answer 24

the larval stage

Question 25

Which species causes cystic echinococcosis?

Answer 25

Echinococcus granulosus

Question 26

Which species causes alveolar echinococcosis?

Answer 26

Echinococcus multilocularis

Question 27

Where does Echinococcus granulosus occur?

Answer 27

worldwide, mostly in rural grazing areas

Question 28

Where does Echinococcus multilocularis occur?

Answer 28

northern hemisphere

Question 29

What is the pathology of cystic echinococcosis?

Answer 29

symptoms only occur when cysts become very large. cysts rupturing causes fever, anaphylactic shock, cyst dissemination. mostly liver and lung involvement, but also brain, bones, heart

Question 30

What is the pathology of alveolar echinococcosis?

Answer 30

affects the liver as a slow-growing tumor. causes abdominal pain, biliary obstruction, occasionally metastatic lesions in lungs and brain

Question 31

How can echinococcosis be diagnosed?

Answer 31

ultrasonography or other imaging techniques supported with serologic tests

Question 32

What is the treatment for echinococcosis?

Answer 32

surgery to remove cyst may not be 100% effective, so albendazole may be used to prevent recurrence. Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to tubulin, which inhibits its assembly into microtubules.