Dr. Libman -- Parasitology 4: Trematodes and Cestodes Flashcards Preview

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Flashcards in Dr. Libman -- Parasitology 4: Trematodes and Cestodes Deck (79)
1

What are trematodes commonly known as?

Flukes

2

Phylum under which cestodes and trematodes belong

Platyhelminthes

3

4 types of trematodes

  1. Schistosoma
  2. Opisthorchis
  3. Paragonimus
  4. Fasciola

4

Location of adult schistosoma

Human blood

5

Location of adult opisthorchis

Human liver

6

Location of adult paragonimus

Human lung

7

Location of adult fasciola

Human liver

8

Source of schistosoma

Water

9

Source of opisthorchis

Freshwater fish

10

2 sources of paragonimus

Freshwater crabs and cray fish

11

Source of fasciola

Watercress

12

Types of flukes that are hermaphroditic

Liver flukes, lung flukes, etc

13

Type of flukes that have two sexes

Blood flukes

14

Describe the general trematode life cycle (5 steps)

  1. Adult lives in human
  2. Lays egg
  3. Miracidium released 
  4. Snail harbors redia/sporocysts
  5. Cercaria released and enters human through tissue (~2 days) OR metacercaria released into/onto fish, crabs and watercress

15

Describe the mating process of schistoma

Female lives inside the male and they mate for life while hugging

16

Location of schistosomule maturation

Portal veins near liver

17

Location of schistosoma eggs in human

Small venules of pelvic or mesenteric venous plexuses

18

Describe the fate of schistosoma eggs

Pass through tissue to lumen of bladder or colon (depends on location) and are voided

OR

Pass into venules and end up in liver

19

4 organisms of intestinal schistosomiasis

  1. S. mansoni
  2. S. japonicum
  3. S. intercalatum
  4. S. mekongi

20

Urinary schistosomiasis

S. hematobium

21

Distribution of S. hematobium (3)

  1. Sub-saharan africa
  2. Some middle east
  3. Madagascar

22

Geographic distribution of S. japonicum (2)

  1. Eastern China
  2. Southerm Japan

23

Geographic distribution of S. mansoni (4)

  1. Sub-saharan Africa
  2. Some middle east
  3. East coast of brazil
  4. Some Caribbean

24

Consequence of schistosomas eggs landing in liver as opposed to leaving the body

Portal fibrosis --> portal hypertension

25

4 types of clinical manifestations of intestinal schistosomiasis

  1. Portal hypertension
  2. Pulmonary hypertension
  3. CNS lesions
  4. Intestinal polyposis

26

4 manifestations of portal hypertension in intestinal schistosomiasis

  1. Splenomegaly
  2. Esophageal varices
  3. Hypersplenism
  4. Ascites

27

2 CNS lesions associated with intestinal schistosomiasis

  1. Spine = transverse myelitis
  2. Cerebral = seizures (S. japonicum)

28

3 manifestations of intestinal polyposis in intestinal schistosomiasis

  1. Both sessile and pedunculated contractures
  2. Intusseception
  3. Chronic salmonellosis

29

5 ways to diagnose intestinal schistosomiasis

  1. Stool ova
  2. Serology
  3. Large intestine
  4. Liver biopsy
  5. Ultrasound

30

Presentatino of urinary schistosomiasis (7)

  1. Hematuria (terminal)
  2. Urinry frequency
  3. Pyuria
  4. Pyelonephritis
  5. Obstructive uropathy
  6. Cancer of bladder (squamous cell)
  7. Distant metastases (spinal column; pulmonary HTN)

31

5 ways to diagnose urinary schistosomiasis

  1. Debris in urine
  2. Eggs in urine (overnight-millipore)
  3. IVP abnormalities
  4. Cystoscopy
  5. Serology

32

Only treatment for schistosomiasis

Praziquantel

33

4 liver flukes and their geographic distributions

  1. Opisthorchis viverini (Oriental)
  2. Clonorchis sinensis (Oriental)
  3. Fasciola hepaticum (Worldwide)
  4. Metorchis conjunctus (Canada)

34

How do liver flukes get to the liver?

Via intestine to do one of two things:

  1. Enter the biliary tree or gallbladder
    • Clonorchis
    • Opisthorchis
    • Metorchis
  2. Hard way = break through intestinal wall and lier parenchyme to reach the same destination
    • Fasciola

35

Geographic distribution of Clonorchis sinensis (4)

  1. China
  2. Vietname
  3. Philippines
  4. South Korea

36

Geographic distribution of opisthorchis fileneus (2)

  1. Eastern Europe (incl Russia)
  2. Kazakhstan

37

Geographic distribution of opisthorchis viverni

Southeast asia

38

Presentation of new liver fluke infection (3)

  1. Pain in liver
  2. Fever
  3. Eosinophilia

39

Presentation of chronic liver fluke infection (3)

  1. Ascending cholangitis
  2. Multiple liver abscesses
  3. Cholangiocarcinoma

40

3 ways to diagnose liver flukes

  1. Eggs in stool
  2. Adults in biliary drainage
  3. CT

41

Define a tapeworm

A flat, hermaphroditic, gutless (i.e. segmental) freight train of a worm

42

Fish tapeworm

Diphyllobothrium spp.

43

Geographic distribution of Diphyllobothrium spp.

Worldwide (dendriticum in north)

44

What puts you at risk of acquiring Diphyllobothrium infection

Raw freshwater fish consumption

45

2 presentations of fish tapeworm infection

  1. Asymptomatic
  2. Intermittant abdominal pains

46

Diphyllobothrium Treatment

Praziquantel 600 mg once

47

Deficiency associated with D. latum (fish tapeworm)

B12 deficiency (mostly FInland)

48

Beef tapeworm

Taenia saginata

49

Pork tapeworm

Taenia solium

50

DIfference between T. solium (pork) and T. saginata (beef)

Similar gross appearance but:

  • Saginata = lots of uterine branches
  • Saginata = more motile, so may crawl out of butt

51

Geography of T. saginata

Raw beef eating countries (i.e. Ethiopia and Lebanon)

52

Geography of T. solium

Areas of pig raising and/or poor sanitation

53

Risk factor for acquiring Taenia infection

Raw meat eating

54

3 presentations of Taenia infection

  1. Asymptomatic
  2. Rare intermittent abdominal pains
  3. T. solium = cysticercosis

55

Taenia saginata/solium treatment

Praziquantel

56

At what life cycle stage for taenia solium cause cysticercosis

Larval stage

57

Describe the NORMAL lifecycle of T. solium (6 steps)

  1. Human carries tapeworm
  2. Human poops out tapeworm -- segments of worm or eggs or both in poop
  3. Pig eats poop
  4. Pig develops muscle cyst
  5. Human kills pig to make uncooked pork chops
  6. Human eats muscle cyst

58

Definitive host of T. solium

Human

59

Intermediate host of T. solium

Pig

60

Dead end host of T. solium and consequence

  • Human (and dog, cat, deer, etc; not pig)
    • Human eats poop but tapeworm thinks you're a pig and tries to make muscle cyst and doesn't know where to go
    • Worm ends up in brain --> cystacercal larvae in brain

61

Clinical picture of T. solium-induced cysticersosis (3 main with subpoints)

  1. Intracerebral space occupying (1.5 cm) lesion
    • Headache
    • Seizures
    • Focal neurological defects
  2. CSF flow obstruction --> hydrocephalus
  3. Basalar meningitis
    • Cranial nerve palsies
    • Hydrocephalus

NOTE: manifestations occur when larvae die and become inflammatory

62

Geographic distribution of cysticercosis due to T. solium

Central America and South America

63

Dog tapeworm

Echinococcus granulosis

64

Definitive host of E. granulosis

Human

65

Describe the sylvatic (Canada) life cycle of E. granulosis (5)

  1. Hydatid cyst (larval) develops in liver of caribou or moose
  2. Wolf kills the caribou/moose and eats its liver
  3. Adult tapeworm in wolf
  4. Wolf poops out parts of tapeworm
  5. Caribou/moose eats grass with wolf poop

66

Describe the pastoral life cycle of E. granulosis (4)

  1. Infected farm dog poops out tapeworm
  2. Sheep eats dog poop in grass --> develop hydatid cysts in liver
  3. Farmer kills sheep
  4. Farmer gives leftover bits (i.e. liver) for dog to eat
  5. Dog gets adult tapeworm

67

Geographic distribution of E. granulosis sylvatic (2) and pastoral (3)

  • Sylvatic = Canada and Alaska
  • Pastoral = Southwest USA, parts of Mexico, Southern South America

68

What can form inside liver cysts of E. granulosis

Daughter cysts

69

Common alternative location for E. granulosis

Lung

70

3 complications of dog tapeworm

  1. Rupture
  2. Superinfection
  3. Mass effect

71

5 locations/symptoms of cyst rupture with dog tapeworm

  1. Peritoneum
  2. Pleura
  3. Biliary tree
  4. Anaphylaxis
  5. Spill into any system --> metastatic cysts

72

Consequence of superinfection of dog tapeworm cyst

Liver abscess

73

When does dog tapeworm cause pathology in humans?

If humans are an accidental host for the larval stage (i.e. we eat the dog poop)

74

3 mass effects of dog tapeworm cysts

  1. Cholestasis
  2. Portal HTN
  3. Budd-Chiari Syndrome

75

4 treatments for dog tapeworm cysts

  1. Primary = surgery
  2. Percutaneous aspiration, injection of sterilizing agent
  3. Chemotherapy (albendazole; only OK)
  4. Observation (i.e. if cyst is not too big or if patient is older or has underlying disease --> cyst may be dead)

76

4 indications for surgery of dog tapeworm cyst

  1. Leaking cysts
  2. Infected cysts
  3. Multiple daughter cysts
  4. Biliary tree communication

77

3 indications for PAIR treatment of dog tapeworm cysts

  1. Pregnancy
  2. Little internal echogenic material
  3. Concomitant disease

78

2 indications for chemotherapy of dog tapeworm cysts

  1. Inoperable
  2. In-aspiratable

79

4 indications for observation of a dog tapeworm cyst

  1. Pastoral strain
  2. Extreme age
  3. Much calcification
  4. Well-padded small cysts