Trematodes

Question 1

Trematodes Adult Worms

Answer 1

• Usually flat
• Elongated
• Leaf shaped
• Two cup-shaped muscular suckers
• Oral sucker
• Ventral sucker used for attachment

Question 2

Hermaphroditic Fluke

Answer 2

• Bisexual
• Highly branched reproductive organs
• Paragonimus westermani
• Fasciola hepatica
• Clonorchis sinensis
• Fasciolopsis buski
• Heterphyes heterophyes
• Metagonimus yokagawai

Question 3

Unisexual Adult Worms

Answer 3

• Both male and female
• Schistosoma mansoni
• Schistosoma japonicum
• Schistosoma haemtobium

Question 4

Trematodes Life Cycle

Answer 4

1) Adult lives in specific organs or blood
2) Eggs are found in particular specimen depending on species
3) Eggs contaminate environment
4) Eggs contain larvae (mirachidium)
5) Mirachidium infects specific snail species
6) Mirachidium forms sporocyst, which then develops into cercariae
7) Cercariae are free swimming

Question 5

Sites Eggs are found

Answer 5

1) Sputum - lung fluke (P. westermani)
2) Feces - intestines (S. mansoni, S. japonicum, F. buski, H. heterophyes, F. hepatica, C. sinensis)
3) Urine - bladder (S. haematobium)

Question 6

Cercariae pathways

Answer 6

1) Schistosomes (species found in blood)
- Cercariae emerge from snail and penetrate skin of humans
2) In F. buski and F. hepatica
- Encyst attaches to water plants and eaten by humans
3) H. heterophyes, C. sinensus, & P. westermani
- Enters the second intermediate host (fish or crabs) which is eaten by humans

Question 7

Trematodes Pathology

Answer 7

Lesions which depend upon location, number of adult worms, and effect eggs and metabolic products have on host

Question 8

Paragonimus westermani Distribution

Answer 8

Found in far east
Japan, China, Micronesia, New Guinea, Korea, Vietnam, Thailand, Cambodia, India, and Philippines

Question 9

Paragonimus westermani Symptoms

Answer 9

Chest pain
Cough
Blood tinged sputum (appears pepper-like and blood streaked)

Question 10

Paragonimus westermani Adult

Answer 10

Encyst in the lung
Frequently in pairs
1 mm x 5 mm

Question 11

Paragonimus westermani Egg

Answer 11

85 x 55 mm
Terminal shell thickening
Shouldered operculum
Operculum has rim

Question 12

Fasciola hepatica Distribution

Answer 12

Sheep and cattle-raising countries

Question 13

Fasciola hepatica Symptoms

Answer 13

Causes liver cirrhosis

Question 14

Fasiola hepatica Adult

Answer 14

35 mm x 15 mm

Question 15

Fasiola hepatica Egg

Answer 15

150 x 90 um
Operculated

Question 16

Clonorchis sinesis Distribution

Answer 16

Found in far east
Japan, Korea, Vietnam, and China

Question 17

Cloronochis sinesis Symptoms

Answer 17

Inflammatory changes
Feeding of adult in biliary passages
Jaundice due to bile duct pathology
Diarrhea
Abdominal pain

Question 18

Clonorchis sinesis Adult

Answer 18

Measures 19 mm x 3.5 mm

Question 19

Clonorchis sinesis Egg

Answer 19

30 um x 16 um
Small terminal knob
Thickened rim around operculum - “shouldered operculum”

Question 20

Clonorchis sinesis Diagnostic Stage

Answer 20

Egg in stool

Question 21

Fasciolopsis buski Distribution

Answer 21

China, India, Vietnam, and Thailand

Question 22

Fasciolopsis buski Adult

Answer 22

20-30 mm x 10 mm

Question 23

Fasciolopsis buski Pathology

Answer 23

• Mucosal ulcers
• Pain
• Nausea
• Diarrhea

Question 24

Fasciolopsis buski Egg

Answer 24

Same as F. hepatica
Cannot differentiate between the two

Question 25

Fasciolopsis buski Infectious Stage

Answer 25

Ingestion of water chestnuts contaminated with metacercaria

Question 26

Fasciolopsis buski Diagnostic Stage

Answer 26

Egg in stool

Question 27

Schistosoma japonicum Distribution

Answer 27

Far East

Question 28

Schistosoma japonicum Common Name

Answer 28

Oriental Blood Fluke

Question 29

Schistosoma japonicum Pathology

Answer 29

• Granuloma of liver or intestines
• Cirrhosis
• Most pathogenic

Question 30

Schistosoma japonicum Egg

Answer 30

80 x 60 um
Small indistinguishable lateral spine

Question 31

Schistosoma japonicum Diagnostic Stage

Answer 31

Egg in stool

Question 32

Schistosoma mansoni Distribution

Answer 32

Africa, Middle East, and South America

Question 33

Schistosoma mansoni Pathology

Answer 33

Bilharzia
Granuloma of liver, intestines, and bladder
May cause cirrhosis

Question 34

Schistosoma mansoni Egg

Answer 34

160 um x 80 um
Prominent lateral spine

Question 35

Schistosoma mansoni Diagnostic Stage

Answer 35

Egg in stool

Question 36

Schistosoma haematobium Distribution

Answer 36

Nile River Valley, African, Middle East

Question 37

Schistosoma haematobium Pathology

Answer 37

Squamous cell carcinoma of bladder

Question 38

Schistosoma haematobium Egg

Answer 38

160 um x 80 um
Terminal spine

Question 39

Schistosoma haematobium Diagnostic Stage

Answer 39

Eggs in urine

Question 40

Schistosoma dermatitis Distribution

Answer 40

Cosmopolitan

Question 41

Schistosoma dermatitis Pathology

Answer 41

Dermatitis (inflammation and localized edema)

Question 42

Schistosoma dermatitis Infectious Stage

Answer 42

Cercariae penetration of skin

Question 43

Schistosoma dermatitis Diagnostic Stage

Answer 43

Rash after swimming

Question 44

Schistosoma dermatitis Common Name

Answer 44

Swimmer’s Itch
Clam Digger’s Itch
Whirl Pool Dermatitis

Question 45

Paragonimus westermani Common Name

Answer 45

Oriental Lung Fluke

Question 46

Paragonimus westermani Infectious Stage

Answer 46

Ingesting raw crayfish with metacercariae

Question 47

Paragonimus westermani Diagnostic Stage

Answer 47

Eggs in sputum

Question 48

Fasciola hepatica Common Name

Answer 48

Sheep Liver Fluke

Question 49

Fasciola hepatica Infectious Stage

Answer 49

Ingesting watercress contaminated with metacercariae

Question 50

Fasciola hepatica Diagnostic Stage

Answer 50

Egg in stool
Travel history

Question 51

Clonorchis sinesis Common Name

Answer 51

Chinese Liver Fluke

Question 52

Clonorchis sinesis Infectious Stage

Answer 52

Ingesting under cooked fresh water fish contaminated with metacercariae