ZEB 122 Chpt3 81-92 Parasitic Cestodes

Question 1

1. What is the common name for cestodes? a) Flatworms b) Roundworms c) Tapeworms d) Hookworms

Answer 1

Answer: c) Tapeworms Explanation: Cestodes are commonly called tapeworms due to their flat tape-like structure.

Question 2

2 Where do adult cestodes typically reside in their host? a) Liver b) Lungs c) Intestine d) Brain

Answer 2

Answer: c) Intestine Explanation: Adult cestodes are endoparasitic and live in the intestine of vertebrates.

Question 3

3 Which of these is NOT a characteristic feature of cestodes? a) Bilaterally symmetrical b) Possess a digestive system c) Hermaphroditic d) Have a scolex for attachment

Answer 3

Answer: b) Possess a digestive system Explanation: Cestodes lack a digestive system and absorb nutrients directly through their cuticle.

Question 4

4.What is the name of the structure used by cestodes for attachment? a) Proglottid b) Scolex c) Rostellum d) Neck

Answer 4

Answer: b) Scolex Explanation: The scolex or head of the cestode has organs of attachment known as suckers or grooves (bothria).

Question 5

5. How many intermediate hosts are typically involved in the life cycle of most cestodes? a) None b) One c) Two or more d) Always three

Answer 5

Answer: c) Two or more Explanation: The life cycles of most cestodes involve two or more intermediate hosts except for Hymenolepis nana.

Question 6

6. What is the scientific name of the beef tapeworm? a) Taenia solium b) Hymenolepis nana c) Diphyllobothrium latum d) Taenia saginata

Answer 6

Answer: d) Taenia saginata Explanation: The beef tapeworm is scientifically known as Taenia saginata.

Question 7

7Where is Taenia solium infection known to be more prevalent? a) North America b) Central and South America c) Australia d) Antarctica

Answer 7

Answer: b) Central and South America Explanation: Although cosmopolitan

Question 8

8. What is the approximate maximum length a Taenia saginata can reach? a) 1 meter b) 3 meters c) 5 meters d) 10 meters

Answer 8

Answer: c) 5 meters Explanation: T. saginata can reach a length of 5-8 meters.

Question 9

9. What differentiates the scolex of T. solium from that of T. saginata? a) T. solium has hooks T. saginata does not. b) T. saginata has hooks T. solium does not. c) T. solium has a rostellum T. saginata does not. d) T. saginata has suckers T. solium does not.

Answer 9

Answer: a) T. solium has hooks T. saginata does not. Explanation: Both T. solium and T. saginata have four suckers on a pea-shaped scolex. However T. solium also has a row of 4-6 rostellum (hooks).

Question 10

10. What is the definitive host for Taenia species? a) Cattle b) Pigs c) Humans d) Snails

Answer 10

Answer: c) Humans Explanation: Humans are the definitive host for Taenia species. They become infected by eating undercooked beef (T. saginata) or pork (T. solium

Question 11

11What stage of the Taenia life cycle is infective to humans? a) Oncosphere b) Cysticercus c) Embryonated egg d) Procercoid larva

Answer 11

Answer: b) Cysticercus Explanation: The cysticercus also known as bladder-worm is the larval stage found in the muscles of the intermediate host (cattle for T. saginata pigs for T. solium).

Question 12

12.When humans ingest this stage in raw or undercooked meat the larva develops into the adult tapeworm in the human intestine. How long does it typically take for the Taenia larva to mature in the human intestine? a) 24 hours b) 1 week c) 2-3 months d) 6-8 months

Answer 12

Answer: c) 2-3 months Explanation: After ingestion of the cysticercus the larva detaches and migrates to the small intestine where it matures within 2-3 months. 13.What is the primary diagnostic method for Taenia infection? a) Blood test b) X-ray c) Stol examination d) Physical examination

Question 13

14.What condition can result from the excessive loss of blood due to Taenia solium infection? a) Epilepsy b) Blindness c) Anaemia d) Paralysis

Answer 13

Answer: c) Anaemia Explanation: The worms cause trauma to their hosts using their suckers and hooks leading to anemia from excessive blood loss.

Question 14

15. What is cysticercosis? a) Infection with the adult tapeworm in the intestine b) Presence of tapeworm larvae in tissues outside the intestine c) Allergic reaction to tapeworm antigens d) Auto-infection with tapeworm eggs

Answer 14

Answer: b) Presence of tapeworm larvae in tissues outside the intestine.Explanation: Cysticercosis is a condition where Taenia larvae (cysticerci) develop in tissues like the brain eyes and muscles causing various neurological disorders.

Question 15

16 Which of the following is the drug of choice for treating Taenia infections? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole

Answer 15

Answer: b) Praziquantel Explanation: Praziquantel is the drug of choice for Taenia infections. 17.What temperature is sufficient to kill Taenia cysticerci in meat? a) -10°C b) 0°C c) 10°C d) 50°C

Question 16

18What does hypobiosis refer to in the context of Taenia infection? a) Rapid growth of the tapeworm b) Arrested development of the larva c) Shedding of gravid proglottids d) Formation of cysts in the host tissues

Answer 16

Answer: b) Arrested development of the larva Explanation: Hypobiosis is the arrested development of the tapeworm larva ensuring that when the process of development to adulthood is impaired the larva can survive for as long as 6-8 months.

Question 17

19. What is the intermediate host for Taenia saginata? a) Pig b) Cattle c) Fish d) Snail

Answer 17

Answer: b) Cattle Explanation: Cattle serve as the intermediate host for Taenia saginata.

Question 18

20What is the intermediate host for Taenia solium? a) Pig b) Cattle c) Fish d) Snail

Answer 18

Answer: a) Pig Explanation: Pigs serve as the intermediate host for Taenia solium.

Question 19

21. What is the common name for Diphyllobothrium latum a) Dwarf tapeworm b) Beef tapeworm c) Pork tapeworm d) Fish tapeworm

Answer 19

Answer d) Fish tapeworm Explanation Diphyllobothrium latum is commonly known as the fish or broad tapeworm

Question 20

22. Where is the infection with Diphyllobothrium latum a more serious problem a) Tropical regions b) Places where properly cooked fish is consumed c) Places where pickled or insufficiently cooked fresh fish is a delicacy d) Arid regions

Answer 20

Answer c) Places where pickled or insufficiently cooked fresh fish is a delicacy Explanation The infection is a more serious problem in places where pickled or insufficiently cooked fresh fish is a delicacy

Question 21

23. What is the maximum length that Diphyllobothrium latum can grow up to a) 2 meters b) 5 meters c) 8 meters d) 10 meters

Answer 21

Answer d) 10 meters Explanation Diphyllobothrium latum can grow up to a length of 8-10 meters

Question 22

24. What is unique about the proglottids of Diphyllobothrium latum a) They are the longest among all tapeworms b) They are shed in chains c) They contain both male and female reproductive organs d) They have bothria on both ventral and dorsal surfaces

Answer 22

Answer c)

Question 23

25. How do humans typically get infected with Diphyllobothrium latum a) Ingesting undercooked beef b) Ingesting undercooked pork c) Consuming contaminated water d) Consuming raw or improperly cooked fish

Answer 23

Answer d) Consuming raw or improperly cooked fish Explanation Human infection with D. latum occurs through the consumption of raw or improperly cooked fish containing plerocercoid larvae

Question 24

25. How do humans typically get infected with Diphyllobothrium latum? a) Ingesting undercooked beef b) Ingesting undercooked pork c) Consuming contaminated water d) Consuming raw or improperly cooked fish

Answer 24

Answer d) Consuming raw or improperly cooked fish Explanation Human infection with D. latum occurs through the consumption of raw or improperly cooked fish containing plerocercoid larvae

Question 25

26. What is the first larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Procercoid d) Oncosphere

Answer 25

Answer b) CoracidiumExplanation The first larval stage is called a coracidium which hatches from eggs in water and is ingested by a crustacean

Question 26

27. What is the second larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Procercoid d) Oncosphere

Answer 26

Answer c) Procercoid Explanation The second larval stage is called a procercoid which develops in the crustacean and then infects a freshwater fish

Question 27

28. What is the third larval stage of Diphyllobothrium latum called? a) Cysticercus b) Coracidium c) Plerocercoid d) Oncosphere

Answer 27

Answer c) Plerocercoid Explanation The third larval stage is called a plerocercoid which develops in the fish and is infective to humans

Question 28

29. What is the diagnostic stage of Diphyllobothrium latum infection? a) Unembryonated eggs discharged in faeces b) Gravid proglottids c) Plerocercoid larvae d) Adult worms in the small intestine

Answer 28

Answer a) Unembryonated eggs discharged in faeces Explanation Diagnosis of D. latum infection is based on finding unembryonated eggs discharged in faeces

Question 29

30. Which vitamin deficiency can be caused by Diphyllobothrium latum infection? a) Vitamin A b) Vitamin B12 c) Vitamin C d) Vitamin D

Answer 29

Answer b) Vitamin B12 Explanation D. latum can compete with the host for vitamin B12 resulting in anemia31. What is sparganosis? a) Infection with the adult D. latum b) Infection with plerocercoid larvae of various Diphyllobothrium tapeworms c) Allergic reaction to D. latum antigens d) Vitamin B12 deficiency caused by D. latum

Question 30

32. What is the drug of choice for treating sparganosis? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole

Answer 30

Answer: b) Praziquantel Explanation: Praziquantel is the drug of choice for treating sparganosis.

Question 31

33. What is a control measure for Diphyllobothrium latum infection? a) Proper cooking of beef b) Proper cooking of pork c) Proper sewage disposal d) Vaccination

Answer 31

Answer: c) Proper sewage disposal Explanation: Proper sewage disposal especially of human faeces is a control measure for D. latum infection.

Question 32

34. What is the common name for Hymenolepis nana? a) Fish tapeworm b) Beef tapeworm c) Dwarf tapeworm d) Pork tapeworm

Answer 32

Answer: c) Dwarf tapeworm Explanation: Hymenolepis nana is commonly called the dwarf tapeworm.

Question 33

35. What is unusual about the life cycle of Hymenolepis nana compared to other tapeworms? a) It requires three intermediate hosts b) It does not require an intermediate host c) It can complete its life cycle in the same host d) It has a free-living larval stage

Answer 33

Answer: c) It can complete its life cycle in the same host Explanation: The adult worm is about 20-30mm in length It is peculiar because it can complete its life cycle in the absence of the intermediate host (usually a beetle) unlike other tapeworms.

Question 34

36. What is the typical intermediate host for Hymenolepis nana? a) Cattle b) Pig c) Fish d) Arthropod

Answer 34

Answer: d) Arthropod Explanation: The intermediate host for H. nana is usually an arthropod such as a beetle or flea.

Question 35

37. How do humans typically get infected with Hymenolepis nana? a) Consuming undercooked meat b) Consuming contaminated water c) Ingesting infected arthropods d) Contact with infected animals

Answer 35

Answer: c) Ingesting infected arthropods Explanation: Humans become infected by ingesting arthropods that are infected with the cysticercoid larva.

Question 36

38. What is the diagnostic stage of Hymenolepis nana infection? a) Adult worms in the small intestine b) Cysticercoid larva in arthropods c) Eggs or proglottids in faeces d) Oncospheres in the environment

Answer 36

Answer: c) Eggs or proglottids in faeces Explanation: Diagnosis of H. nana infection is based on finding the egg or proglottid in feces.

Question 37

39. What is the drug of choice for treating Hymenolepis nana infection? a) Niclosamide b) Praziquantel c) Albendazole d) Mebendazole

Answer 37

Answer: a) Niclosamide Explanation: Niclosamide is the drug of choice for H. nana infection Praziquantel is also effective.

Question 38

40. What is the causative agent of hydatid disease? a) Taenia solium b) Diphyllobothrium latum c) Hymenolepis nana d) Echinococcus granulosus

Answer 38

Answer: d) Echinococcus granulosus Explanation: The larvae of cestodes of the genus Echinococcus (E. granulosus and E. multilocularis) are the causative agents of hydatid disease.

Question 39

41. Where is Echinococcus granulosus infection particularly prevalent a) North America b) South America and Europe c) Australia d) Antarctica

Answer 39

Answer: b) South America and Europe Explanation: E. granulosus is cosmopolitan but more prevalent in South America and Europe

Question 40

42. What is the definitive host for Echinococcus granulosus a) Humans b) Cattle c) Domestic and wild carnivores d) Rodents

Answer 40

Answer: c) Domestic and wild carnivores Explanation: Domestic and wild carnivores are the hosts of the adult worm

Question 41

43. What is the infective stage of Echinococcus granulosus for humans a) Adult worm b) Hydatid cyst c) Gravid proglottid d) Oncosphere

Answer 41

Answer: b) Hydatid cyst Explanation: The infective stage is the hydatid cyst which develops in intermediate hosts like sheep cattle and humans

Question 42

44. How do humans typically get infected with Echinococcus granulosus a) Consuming undercooked meat b) Ingesting contaminated food or drink c) Contact with infected animals d) Insect bites

Answer 42

Answer: b) Ingesting contaminated food or drink Explanation: Humans are infected by ingesting food or drink contaminated with E. granulosus eggs usually from contact with infected carnivores or their faeces

Question 43

45. What organ is most commonly affected by hydatid cysts in humans a) Brain b) Lungs c) Liver d) Kidneys

Answer 43

Answer: c) Liver Explanation: The cysts most commonly affect the liver but can also occur in the lungs brain and other organs

Question 44

46. Describe the morphology of adult cestodes

Answer 44

Answer: Adult cestodes have a flat tape-like body composed of segments called proglottids. They have a scolex or head with specialized structures for attachment such as suckers and hooks. They lack a digestive system and absorb nutrients through their cuticle

Question 45

47. Outline the general life cycle of a tapeworm

Answer 45

Answer: The general life cycle of a tapeworm involves Adult Stage Adult tapeworms reside in the intestine of the definitive host (usually a vertebrate) Egg Release They release eggs that are passed in the host’s feces Intermediate Host Eggs are ingested by an intermediate host (another animal) Larval Development Larvae develop in the intermediate host’s tissues Definitive Host Infection The definitive host becomes infected by consuming the intermediate host containing the infective larval stage

Question 46

48. Explain how Taenia solium infection can lead to neurological complications

Answer 46

Answer: Taenia solium infection can lead to neurological complications through a condition called cysticercosis. When humans ingest T. solium eggs the larvae (cysticerci) can migrate to the brain and other tissues forming cysts. These cysts can cause various neurological disorders including epilepsy blindness and paralysis

Question 47

49. What are the key differences between Taenia saginata and Taenia solium infections

Answer 47

Answer: While both T. saginata and T. solium are intestinal tapeworms with similar life cycles and modes of transmission some key differences exist Intermediate Host The intermediate host for T. saginata is cattle while for T. solium it is pigs Scolex Morphology The scolex of T. solium possesses hooks while T. saginata does not Cysticercosis T. solium poses a greater risk of cysticercosis in humans as humans can act as both the definitive and intermediate host

Question 48

50. Discuss the public health significance of cestode infections and measures to prevent them

Answer 48

Answer: Cestode infections are a significant public health concern especially in regions with poor sanitation and hygiene practices. These infections can cause various health problems ranging from mild gastrointestinal discomfort to severe neurological complications Key preventive measures include Proper meat inspection and cooking Improved sanitation and hygiene Safe disposal of human feces Health education to promote awareness about cestode infections and their prevention.