Cestodes Review of Microbiology And Immunology Multiple Choice Question & Answers

1. Operculated eggs in all except?

1. Dipylidium
2. Hymenolepis nana
3. Diphyllobothrium latum
4. Fasciola hepatica

Answer. (1, 2) (Dipylidium, H.nana)

Read And Learn More: Micro Biology And Immunology Multiple Choice Question And Answers

• Operculated eggs are produced by all trematodes except
• Schistosoma and one cestode (i.Diphyllobothrium latum).
• Dipylidium eggs are present in groups of 15 (egg packets).
• Hymenolepis nana eggs are nonbile stained, round-oval, polar filaments between the outer and inner membrane.

2. Cysticercus cellulose is larvae of:

1. Echinococcus granulosus
2. Taenia saginata
3. Taenia solium
4. Hymenolepis nana

Answer. (3) (Taenia solium)

3. Pig tapeworm may cause dangerous disease than beef tapeworm because:

1. Invasion of deep mucosa
2. CNS involvement
3. Larger size
4. Armed scolex
5. Eggs not infective to humans

Answer. (2, 4) (CNS involvement, Armed scolex)

T.solium is capable of invading into CNS.

4. Intermediate host for Taenia saginata is:

1. Man
2. Snail
3. Cattle
4. Pig

Answer. (3) (Cattle)

• Taenia saginata—definite host is man and intermediate host is cattle.
• Taenia solium—definite host is man and intermediate host is pig.

5. Intermediate host for Taenia saginata is:

• Cattle
• Pig
• Man

Answer. (1) (Cattle)

6. T. saginata is differentiated from T. solium by presence of:

1. Hooklets are present in scolex (head)
2. 4 large pigmented sucker
3. Uterus is thin and dichotomous
4. Short neck
5. Egg is not infective to man

Answer. (2, 5) (4 large pigmented sucker, Egg…)

7. Which of the following is the most common location of intracranial neurocysticercosis?

1. Brain parenchyma
2. Subarachnoid space
3. Spinal cord
4. Orbit

Answer. (2) (Subarachnoid space)

• Though brain parenchyma was thought to be the commonest site of Neurocysticercosis but recent evidences have shown that subarachnoid space being the commonest site, followed by brain parenchyma.

8. Cysticercosis is caused by:

1. T. solium
2. T. saginata
3. duodenale
4. granulosus
5. multilocularis

Answer. (1) (T. solium)

• Causative agent of cysticercosis: Taenia solium (Pork Tapeworm)
• Human beings are infected by eating undercooked pork containing the cysticerci.
• Cysticercus cellulose is the larval stage found commonly in
• Pig, but sometimes in humans by drinking contaminated water or by eating uncooked vegetables infected with egg/autoinfection.

9. Which of the following is the most common central nervous system parasitic infection?

1. Echinococcosis
2. Sparganosis
3. Paragonimiasis
4. Neurocysticercosis

Answer. (4) (Neurocysticercosis)

• Parasites causing CNS infections:
• Neurocysticercosis (NCC) is the most common form and accounts for 60–90% cases of Cysticercosis.
• NCC is considered as the most common parasitic CNS infection of man and most common cause of adult-onset epilepsy throughout the world.

10. Cause of epilepsy in up to 50% Indian patients is:

1. Neurocysticercosis
2. Cerebral malaria
3. Toxoplasmosis
4. Cerebral hydatid cyst
5. Echinococcus Granulosus

Answer. (1) (Neurocysticercosis)

• Neurocysticercosis accounts for 50% cases of late-onset epilepsy in Indian patients.

11. Adult worms of Echinococcus granulosus live in?

1. Human’s intestine
2. Dog’s intestine
3. Human’s liver
4. Dog’s liver

Answer. (2) (Dog’s intestine)

• Echinococcus granulosus has three forms. The larval form is found in liver and other viscera of intermediate host such as sheep (rarely man) and the adult form resides in Dog’s intestine eggs are excreted in dog’s feces.

12. A 30-year-lady with 3 months history of progressive breathlessness and dyspnea was evaluate chest X-ray showing cavitary lesion in lower lobe of lung. Lobectomy was done and histopathology shows the following image, identify the agent and how many layers it will have?

1. Echinococcus with 2 layers
2. Entamoeba with 1 layer
3. Lung fluke with 1 layer
4. Strongyloides with 2 layers

Answer. (1) (Echinococcus with 2 layers)

• This is picture of hydatid cyst. The cyst wall of hydatid cyst is bilayered ( ectocyst and endocyst).
• There is also a host derived outer pericyst layer.

13. Water lily sign is seen in infection due to:

1. Neurocysticercosis
2. Schistosomiasis
3. Filariasis
4. Echinococcus infection

Answer. (4) (Echinococcus infection)

• Water lily sign is seen in hydatid disease and is due to detached cyst floating within the cavity.

14. All are true about hydatid cyst, except:

1. Dog is the definitive host
2. Man is the intermediate host
3. Liver is the most common site of infection
4. The egg is labile at extremes of temperature

Answer. (4) (The egg is labile at extremes of temperature)

Echinococcus eggs remain viable in water and damp sand for three weeks at 30°C, 225 days at 6°C, and 32 days at 10–21°C.

15. Dog is the host for:

1. Toxocara canis
2. Echinococcus granulosus
3. Echinococcus vogeli
4. Taenia solium
5. Taenia saginata

Answer. (1, 2, 3) (Toxocara canis, Echinococcus granulosus, Echinococcus vogeli)

• Echinococcus granulosus (dog tape worm), Echinococcus vogeli (Bush dogs are final host).
• Toxocara canis (also known as dog roundworm) is worldwide-distributed helminth parasite of dogs.

16. Skin test useful in hydatid disease is:

1. Casoni’s test
2. Schick test
3. Patch test
4. Dick’s test

Answer. (1) (Casoni’s test)

• Casoni’s test done for hydatid disease
• Schick test done for diphtheria
• Patch test done for filariasis
• Dick’s test done for Streptococcus.

17. Intermediate host for hydatid disease:

1. Man
2. Dog
3. Cat
4. Foxes

Answer. (1) (Man)

• Causative agent of hydatid disease: Echinococcus granulosus/ dog tape worm/ hydatid worm
• Definitive host: Dog and other canine animals
• Intermediate host: man
• Habitat: Man harbors the larval form, which is found within the hydatid cyst
• It represents the structure of the scolex of the future adult worm.

18. PAIR stands for:

1. Percutaneous Aspiration Injection and Reaspiration
2. Pervenous Aspiration Injection and Reaspiration
3. Per subcutaneous Aspiration Injection and Reaspiration
4. Diphyllobothrium Latum

Answer. (1) (Percutaneous Aspiration Injection and…)

• PAIR (Percutaneous Aspiration Injection and Reaspiration) is a semi conservative surgery done for hydatid disease.

19. True about diphyllobothrium:

1. Man is single host
2. Iron deficiency anemia is seen
3. Operculated egg is diagnostic
4. Fish is the definitive host

Answer. (3) (Operculate…)

• Diphyllobothrium has three hosts. Man is definitive host, Cyclops are the 1st intermediate host and fish is the 2nd intermediate host
• It causes megaloblastic anemia (due to absorption of vitamin B12 from intestine)
• Operculated egg is the diagnostic form seen in stool.

20. Second intermediate host to Diphyllobothrium latum is:

1. Cyclops
2. Man
3. Snail
4. Freshwater fish

Answer. (4) (Freshwater fish)

• Diphyllobothrium latum or fish tapeworm or broad tapeworm:
• Definitive host: man, dog, and cat.
• Intermediate host: 1st Cyclops/diaptomus, 2nd – fresh water fish

21. Helminth implicated in causing pernicious anemia is:

1. Diphyllobothrium latum
2. Ascaris
3. Taenia solium
4. Hymenolepis nana

Answer. (1) (latum)

• D.latum adult worm sucks vitamin B from intestine leading to Pernicious anemia.

22. Egg with single knob, hooks polar filaments. What is the correct statement?

1. Treatment of choice is albendazole
2. Disease transmitted by uncooked pork
3. Both adult and larva stages of parasite are seen in host
4. Transient diarrhoea cured spontaneously

Answer. (3) (Both adult and larva…)

• H.nana transmission occurs to man by Ingestion food and water contaminated egg → egg develops to larva → Larva develops to adult → adult undergoes self fertilization and produce eggs→ Eggs are released in feces
• Both adult and larval stages are seen in human intestin(Correct statement).
• H.nana infection is not self-limiting. Treatment is needed.
• Drug of choice for this condition is Praziquantel and Niclosamide

23. A child with 10 days abdominal pain presented to OPStool microscopy was done which showed the given findings. What is the DOC· for the disease caused by the given organism?

1. Albendazole
2. Mebendazole
3. Praziquantel
4. Pyrantel pamoate

Answer. (3) (Praziquantel).

• The picture shows eggs of Hymenolepis nana (non bile stained egg with polar filaments between the shell membranes in the stool). The drug choice for this parasitic infection is praziquantel.

24. All of the following have operculated eggs except:

1. Clonorchis sinensis
2. Diphyllobothrium latum
3. Hymenolepis dimunita
4. Fasciola hepatica

Answer. (3) (Hymenolepis dimunita)

The egg of Diphyllobothrium latum and eggs of all the trematodes are characteristically operculated except that of schistosomes.

25. Dwarf tapeworm refers to:

1. Echinococcus
2. Loa Loa
3. Hymenolepsis nana
4. Schistosoma mansoni

Answer. (3) (Hymenole…)

• H. nana or Dwarf tape worm (smallest tapeworm/cestode) (adult form measures 1–4 cm in length)
• Diphyllobothrium latum is the largest cestode affecting man (adult form measures up to 10 meter).
• Properties Fasciola hepatica Fasciolopsis buski
• Size Smaller (3 cm) Bigger (2–7.5 cm)
• Anterior end (shoulder) Bears cephalic cone Does not have cephalic cone
• Oral and ventral suckers Well separated Lie close to each other
• Intestinal caeca Bear lateral branches Do not have lateral branches

26. Which of the following egg contains three pairs of hooklets and polar filaments but bile nonstained?

1. H. nana
2. T. solium
3. T. saginata
4. granulosus
5. latum

Answer. (1) (H. nana)

• All cestode eggs contain an eggshell and an oncosphere with three pairs of hooklets and bile stained:
• H. nana eggs contains Polar filaments and is bile nonstained
• Diphyllobothrium latum eggs are operculated.
• H. nana eggs
• Eggs are the infective form as well as diagnostic form of the parasite.
• Egg is round to slightly oval, 30–47µm size, Nonbile stained (colorless in saline mount)
• It has two membranes and an oncosphere with six hooklets
• Polar filaments: 4–8 polar filaments emerge from poles and lie between the two membranes.

27. Which of the following parasite’s life cycle is shown below?

1. Fasciola buski
2. Fasciola hepatica
3. Paragonimus westermani
4. Clonorchis sinensis

Answer. (2) (Fasciola hepatica)

• This picture given here is a life cycle of Fasciola hepatica.
• Both Fasciola hepatica and Fasciolopsis buski have similar life cycle.
• Ingestion of Metacercaria (infective form) → metacercaria transforms to adult worm→adult worm lay eggs passed in feces → Eggs hatch to form miracidium (L1) larva in water
  → Miracidium is infective to snail → Miracidium develops to sporocyst→ rediae→ cercaria (infective to aquatic plant) → Cercaria develops into metacercaria.
• However, Fasciola hepatica is a better answer here as it can be differentiated from
• Fasciolopsis buski by the morphology of adult worm as depicted in the figure below.
• Fasciola hepatica Fasciolopsis buski

28. Aquatic plants are second intermediate host for which of following trematode?

1. Fasciola hepatica
2. Paragonimus
3. Clonorchis sinensis
4. Schistosoma

Answer. (1) (F. hepatica)

29. Which one cannot act as definitive host of Clonorchis sinensis?

1. Dogs
2. Pigs
3. Cats
4. Cows
5. Goats

Answer. (4, 5) (Cows, Goats)

• The definitive hosts for Clonorchis are fish-eating mammals such as dogs, cats, rats, pigs,badgers, weasels, camels, and buffaloes. Man is an accidental definitive host.
• First intermediate host is snail and second intermediate host is freshwater fish.

30. A 15-year-old complains of loose motion, intermittent abdominal pain of 1-year wet mount of stool shows multiple ova > 100 microns in length. Which of the following agent is responsible?

1. Fasciola gigantica
2. Gastrodiscoides hominis
3. Ancyclostoma caninum
4. Ophistotichus viverni

Answer. (1) (Fasciola gigantica)

• Among the options, eggs of Fasciola Gigantica are larger > 100 µm size and Fasciola
• Gigantica is associated with fever and abdominal symptoms.
• Option a: Fasciola Gigantica:
  • Eggs are oval, bile stained, unembryonated and operculated, larger in size (160–190 µm × 70–90 µm).
  • Acute disease develops during metacercariae migration (1–2 weeks after infection) and includes fever, right-upper-quadrant pain, hepatomegaly and eosinophilia.
• Option b: Gastrodiscoides Hominis
  • Eggs are operculated, measures 150 µm × 60–70 µm size.
  • Light infection is asymptomatic whereas heavy infection may cause mucus diarrhea and other intestinal symptoms.
• Option c: Ancyclostoma Caninum causes Cutaneous larva migrans, eggs are not found in humans, found only in canine animals feces. Only the larvae are found in men.
• Option d: Opisthorchis Viverrini-Eggs: Measure 27 µm × 15 µm, flask-shaped with an operculum and a knob.

31. Effective drugs for Fasciola hepatica:

1. Bithionol
2. Praziquantel
3. Triclabendazole
4. Metronidazole
5. Niclofolan

Answer. (1, 2, 3) (Bithionol, Praziquantel, Triclabendazole)

• Triclabendazole is the DOC for F.hepaticBithionol and Praziquantel are the alternative drugs.

32. Which organism can be isolated from stool and sputum?

1. Paragonimus
2. Fasciola
3. Chlonorchis
4. P. carini

Answer. (1) (Paragonimus)

• Eggs of Paragonimus westermanii can be isolated from stool and sputum.

33. Cercariae are infective form of:

1. S. hematobium
2. P. westermanii
3. F. hepatica
4. T. solium

Answer. (1) (S. hematobium)

• Metacercaria larva are the infective form for all the trematodes, expect Schistosoma where cercarial larva are the infective form.

34. A man after return from complains of pain abdomen, jaundice with increased alkaline phosphatase and conjugated hyperbilirubinemia: USG shows blockade of the biliary treWhat could be the cause?

1. Fasciola buski
2. Strongyloides
3. Clonorchis sinensis
4. Gnathostoma spinigerum

Answer. (3) (Clonorchis sinensis)

• Pain abdomen, jaundice with increased alkaline phosphatase and conjugated hyperbilirubinemia shows blockade of the biliary treSuggestive of infection by
• Clonorchis sinensis infection.

Clonorchiasis and opisthorchiasis:

• Low worm burden: asymptomatic.
• Moderate to heavy infection may be associated with vague right-upper-quadrant pain.
• Chronic or repeated infection is associated with manifestations such as Cholangitis,cholangiohepatitis, and biliary obstruction.
• Cholangiocarcinoma is epidemiologically related to sinensis infection in China and to O. viverrini infection in Northeastern Thailand.

35. A 7-year-old presented with intermittent abdominal cramps, loose stool and on stool examination eggs of size 100 µm are seen, which is not the cause:

1. Fasciola gigantica
2. Echinostoma iliocanum
3. Gastrodiscoides hominis
4. Opisthorchis viverrini

Answer. (4) (Opisthorchis viverrini)

• Fasciola gigantica: 160 µm
• Echinostoma iliocanum: Measures 90–125 µm
• Gastrodiscoides hominis: Measures 150 µm
• Opisthorchis viverrini: Measures 11–30 µm
• Based on the clue provided in the history the most probable answer is Opisthorchis
• viverrini as it is much smaller in size (measures 11–30 µm).

36. Parasites causing lung infestation are:

1. H. nana
2. Paragonimus westermanii
3. Taenia saginata
4. granulosus
5. multilocularis

Answer. (2, 4) (Paragonimus westermanii and granulosus)

• Parasites causing lung infestation are:
• Paragonimus westermanii (Lung fluke)
• Ascaris lumbricoides (larva)
• Hookworm (larva)
• Echinococcus granulosus
• Strongyloides stercoralis (larva)
• Entamoeba histolytica.

37. Cholangiocarcinoma is caused by:

1. Fasciola infestation
2. Clonorchis infestation
3. Paragonimus infestation
4. Ascaris infestation
5. None of these

Answer. (2) (Clonorchis infestation)

38. Which is not a liver fluke?

1. Paragonimus
2. Clonorchis sinensis
3. Gnathostoma spinigerum
4. Opisthorchis viverinii
5. Whipworm

Answer. (1, 3, 5) (Paragonimus, Gnathostoma spinigerum, Whipworm)

• Liver fluke
• F.hepatica
• Fascola gigantica
• Clonorchis sinensis
• Opisthorchis viverinii.

39. Katayama fever is seen in:

1. Schistosoma haematobium
2. Sch. mansoni
3. Sch. japonicum
4. Sch. mekongi

Answer. (2) (Schistosoma haematobium)

• Katayama fever: In the acute phase of Schistosoma mansoni infection, antigens released from the eggs combine with antibodies and form immune complexes, and this serum sickness-like illness called Katayama fever.
• It is characterized by fever, generalized lymphadenopathy, and hepatosplenomegaly.
• S.mansoni is more common to cause Katayama fever than S.japonicum.

40. Terminal spined eggs are seen in:

1. Schistosoma haematobium
2. Sch. mansoni
3. Sch. japonicum
4. Chlonorchis sinensis
5. T. saginata T. solium

Answer. (1) (Schistosoma haematobium)

• Five species of Schistosomes infecting humans:
• Eggs with a terminal spine: Schistosoma haematobium, Schistosoma intercalatum
• Eggs with a lateral spine: Schistosoma mansoni,
• Eggs with a rudimentary knob: Schistosoma japonicum, Schistosoma mekongi