Cestodes Flashcards

1
Q
  • collectively called the______
  • dorsoventrally flattened
  • bilaterally symmetrical
A

Phylum Platyhelminthes

flatworms

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Platyhelminths are covered by a membrane called

A

tegument

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Platyhelminths are hermaphrodite except for

A

Schistosoma species

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Characteristics of Class Cestoda

A

Taenia species (example)
Adult worms are seen in the intestine
Proglottids contain male and female parts
Eggs have 6 hooked embryos
World-wide distribution
nO digestive tract, no circulatory system
Ribbon-like body, flat
Middle (intermediate host is required)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pseudophyllidea
2

A

● Diphyllobothrium latum

● Spirometra: S. erinacei ; S. mansoni ; S. ranarum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Cyclophyllidea
5

A

Taenia solium and Taenia saginata
Hymenolepis nana and Hymenolepis diminuta
Dipylidium caninum
Raillietina garrisoni
Echinococcus granulosus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

CN

T soium

A

Pork tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

CN
T saginata

A

Beef tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T multiceps

A

Coenurus Tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Echinococcus granulosus CN

A

Hydatid Tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Echinococcus multilocularis CN

A

The Multiloculate or
Alveolar Hydatid Tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hymenolepis nana CN

A

Dwarf tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Hymenolepis diminuta CN

A

Rat tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Dipylidium caninum CN

A

Double-pored Tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Diphyllobothrium latum CN

A

Broad Fish Tapeworm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

3 types of proglottid:

A

Immature
Mature
Gravid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

– undeveloped sexual organ, nearest to the neck

A

immature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

– fully mature sexual organ

A

mature

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

– contains fertilized egg, undergoes apolysis

A

gravid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Species of Class Cestoda

Species which require a vertebrate intermediate host

A

Taenia solium (pork tapeworm)
Taenia saginata (beef tapeworm)
Echinococcus granulosus (dogs, carnivores)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Species of Class Cestoda

Species which require an invertebrate intermediate host

A

▪ Dipylidium caninum (dog tapeworm, double-pored tapeworm)

▪ Hymenolepis diminuta (rat tapeworm)

▪ Raillietina garrisoni (Tribolium confusum)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Species of Class Cestoda

Species which may or may not require intermediate host

A

▪ Hymenolepis nana (dwarf tapeworm)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Species of Class Cestoda

Species which infect man in their larval stages

A

▪ Diphyllobothrium latum

▪ Echinococcus granulosus (hydatid worm)

▪ Echinococcus multilocularis

▪ Taenia solium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

D latum

• Scolex is ____ shaped

• Scolex bears 2 slit-like grooves called_______ (1 on the dorsal surface and 1 on the ventral surface)

• Scolex has no ____ and ____

•_____ is thin and unsegmented and is much longer than the head

A

spoon-shaped or spatulate

bothria

no rostellum and no hooklets

Neck

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Morphology

• 3,000 to 4,000 proglottids

• A mature segment is filled with male and female reproductive organs

• Terminal segments shrink and becomes empty as eggs are constantly discharged

• Dried up segments break off from the body in chains and are passed out in the host’s feces

• Uterus at the center of the segment appears in the form of a rosette

A

Diphyllobothrium latum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

D latum

Uterus at the center of the segment appears in the form of a___

A

rosette

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

D latum ova

Bile stained or not?

A

Bile stained

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Ova of _____

• Oval

• Bile stained

• Contains abundant granules and unsegmented ovum

• Inconspicuous operculum at one end and a small knob at the other end

• Does not float in saturated solutions of common salt

• A single egg gives rise to a single larva

• Not infective to man

• About 1 million released everyday

A

D latum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

D latum

First stage larva

• Ciliated oncosphere that develops from egg in water

A

Coracidium

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

D latum

Second stage larva

• Spindle-like solid body with cephalic invagination

• Found inside the_____ (the first IH)

A

Procercoid

cyclops

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

D latum

Third stage larva

• Head is invaginated in the neck

• Found in the_____, the second IH

A

Plerocercoid

fresh water fish

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Diphyllobothrium latum

• Definitive Host

• Habitat

A

• Man, dog, cat

Small intestine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

D latum

• 1 st I.H.

• 2 nd I.H.

A

• Cyclops or Diaptomus

• Fresh water fish, pike, trout, salmon, perch

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

D latum

Mode of Infection

A

• Ingestion of imperfectly cooked infected fish or roe containing plerocercoid larvae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

Diphyllobothrium latum

• Diagnosis

A

• Microscopic examination of feces for the characteristic operculated eggs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

T solium

Color and length

A

whitish, creamy white, measures 3-5 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

T saginata

Color and length

A

white and semitransparent, measures 5- 10 meters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

of segments

T solium

A

800 – 1000

39
Q

of segments

T saginata

A

1000 – 2000

40
Q

T solium scolex

Armed or unarmed

A

Armed

41
Q

T saginata scolex

Aremd or unarmed

A

Unarmed

42
Q

T solium

Proglottids (Mature)

with______

A

accessory ovary

43
Q

T saginata ovary

A

No accessory ovary

44
Q

Taenia solium

Proglottids (Gravid)
Branches

A

8 –12 lateral branches

45
Q

Taenia saginata

Branches

A

15-30 lateral branches

46
Q

Taenia solium

Apolysis

A

In chains

47
Q

Taenia saginata
Apolysis

A

Singly

48
Q

Taenia solium

A

30, 000 t0 50, 000 eggs

49
Q

of eggs/gravid proglottid

T saginata

A

80, 000 eggs

50
Q

IH of solium and saginata

A

Swine/ pig and cow/ cattle

51
Q

D latum

Diagnosis
Cysticercosis

A

Biopsy
(subcutaneous nodule)

X-ray/CT/MRI: cerebral cysticercosis

Ophthalmoscopy: ophthalmic cysticercosis

52
Q

D latum ( taeniasis)

Taeniasis
: to find egg at perianal region

: to find segment (species identification)

A

Anal swab

Fecal exam

53
Q

Scolex

• subglobular in shape with 4 cuplike suckers, has a retractable rostellum armed with single row of 20-30 Y –shaped hooklets

• long and slender neck

A

Hymenolepis nana

54
Q

Scolex

club-shaped with 4 cuplike suckers, rostellum unarmed or devoid of hooks

A

Hymenolepis diminuta

55
Q

Proglottids (Mature)

• segment is narrow

• one ovary more or less straight pattern across

• 3 ovoid testes

A

H nana

56
Q

Proglottids mature

• segment is broad

• bilobed ovary

• 3 globular, widely separated unilateral genital pores

A

H diminuta

57
Q

Proglottids ( Gravid Segment )

narrow, uterus is sac-like irregular

• Testes and ovary disappear

• Uterus hollows out and filled with eggs

A

Hymenolepis nana

58
Q

Proglottids ( Gravid Segment )

• Sac like uterus filled with eggs

• Disintegrate, release eggs into the feces

A

Hymenolepis diminuta

59
Q

• 30-47 μm diameter polar filaments originating from polar knobs at either end of the embryopore

• Polar filaments are 4-8 in number

A

Hymenolepis nana

60
Q

• Has an inner membrane around the oncosphere which has 2 polar knobs but no polar filament

• Fan-like hooklets

• Bile stained

A

Hymenolepis diminuta

61
Q

Hymenolepis nana

Intermediate host

A

flea, beetle, cockroaches

62
Q

H nana vs H diminuta

Does not necessarily require an IH

A

H nana

63
Q

Hymenolepis diminuta

IH

A

flea, beetle, cockroaches, mealworms, earwigs

64
Q

H nana vs H diminuta

Requires an IH

A

H diminuta

65
Q

Hymenolepis nana vs Hymenolepis diminuta

Arthropod IH

Rat flea -
Dog flea -
Human flea -
Flour beetle -

A

Xenopsylla spp.

Ctenophalides canis

Pulex irritans

Tribolium spp.

66
Q

Hymenolepis nana vs Hymenolepis diminuta

Diagnosis

A

• Demonstration of eggs in stool

• Light infection: concentration of stool on alternate days

• Stool exam repeated after 2 weeks

67
Q

H nana vs H diminuta

Are proglottids recovered?

A

Proglottids are not recovered - - - undergo degeneration prior to passage with stools

68
Q

H nana vs H diminuta

Is it possible for whole worm to be recovered

A

Yes

At times whole worm is expelled

69
Q

Which is bigger

Dipylidium caninum vs Raillietina garrisoni

A

Raillietina garrisoni

70
Q

Dipylidium caninum vs

D caninum vs R garrisoni

Scolex

small with 4 deeply cupped suckers and a protrusible rostellum which is armed with 1- 7 rows of rose-thorn hooklets

A

D caninum

71
Q

D caninum vs R garrisoni

Scolex

subglobular and is provided with 4 cuplike suckers with refractile rostellum armed with 2 alternating circular rows of 90-140 hammer shaped hooks

A

Raillietina garrisoni

72
Q

Proglottids (Mature)

• segment is narrow
• double set of reproductive organs and a genital pore at each lateral margin

A

Dipylidium caninum

73
Q

• With bilobed ovary and 36 – 50 ovoid testes

• Genital pore opens on one side near the anterior lateral border of the segment

A

Raillietina garrisoni

74
Q

Dipylidium caninum vs Raillietina garrisoni

Proglottids (Gravid)

• Pumpkin seed-shaped filled with capsules or pockets of 8 – 15 eggs enclosed in embryonic membrane

A

D caninum

75
Q

D caninum vs R garrisoni

Proglottids (Gravid)

• 2 mm in length with 200-400 egg containing 1 –4 spindle shaped eggs
• Enclosed in two membranes : outer – elongated inner – spherical
• Segments – motile, white, “rice grain”

A

Raillietina garrisoni

76
Q

Dipylidium caninum

IH

A

Ctenocephalides canis = dog flea

Ctenocephalides felis = cat flea

Trichoedectes canis = dog louse

Pulex irritans = human flea

77
Q

Raillietina garrisoni

IH

A

Tribolium confusum = flour beetle

78
Q

Dipylidium caninum

Diagnosis

A

• recovery of gravid segments
• egg capsules are rarely passed-out in the feces

79
Q

Raillietina garrisoni
Diagnosis

A

• recovery of gravid segments

• segment is glistening with rice grain appearance

80
Q

Extra Intestinal Cestodes

A

Echinococcus granulosus
Echinococcus multilocularis

Spirometra mansoni Spirometra erinacei Spirometra ranarum

81
Q

Scolex

• bears a prominent rostellum with double row of 20 to 40 large and small hooklets

A

Echinococcus granulosus

82
Q

Segments

3 segments

• 1 immature
• 1 elongated mature
• 1 long gravid

A

Echinococcus granulosus

83
Q

Ova

• subspherical with a brown radially striated embryophore which cannot be differentiated from Taenia eggs

A

Echinococcus granulosus

84
Q

Echinococcus granulosus

• infective stage of the parasite
• 20 cm in diameter
• developing membrane is 2 layers

A

Hydatid cyst

85
Q

E granulosus hydatid cyst

• developing membrane is 2 layers:

A
  1. outer laminated layer
  2. inner nucleated germinal layer
86
Q
  • buds or capsules which contain protoscolices
  • free brood capsule and free scolices are referred to as “HYDATID SAND”
A

inner nucleated germinal layer

87
Q

Hydatid cyst

  • milky opaque
  • non-nucleated layer
A

outer laminated layer

88
Q

Echinococcus granulosus

Life cycle

DH:
IH:
AH:

A

dogs and other canines

sheep, goats, swine

man

89
Q

Echinococcus granulosus

Pathology:

affects primarily the ____ and ____

A

liver and the lungs

90
Q

Echinococcus granulosus

Diagnosis

A

• Unilocular cysts ( only after they have grown to a tremendous size)
• X-RAY
• Exploratory cyst puncture

• Immunologic test
• Intradermal test
• Precipitin test
• CF
• Hemagglutination

• IHA, IFA, EIA

91
Q

Echinococcus multilocularis

Morpholgy:

  • Adult similar to_____
  • 1.2 mm – 3.7 mm
A

E. granulosus

92
Q

Echinococcus multilocularis

Cyst has a thin outer wall that grows and infiltrates into surrounding host tissues.
- Fluid filled pockets containing protoscolices
- Break off and metastasize to other parts of the body forming _____ or ______

A

alveolar or multilocular hydatid cysts

93
Q

Echinococcus multilocularis

Diagnosis:

Prevention :

A
  • Radiological studies alveolar hydatidosis
  • ELISA
  • Deworming of dogs