Parasites- Trematodes

Question 1

Traits of Trematodes (flukes)

Answer 1

dorso-ventrally flattened. unsegmented. leaf-like. Snails ALWAYS intermediate host!!! hermaphroditic/ monoecious except schistosoma. 2 radially striated suckers (oral and ventral). incomplete digestive tract (ends in cecum). most of body is taken up by reproductive organs.

Question 2

What is another name for fasciola hepatica? What is its host? And what are its unique structural characteristics?

Answer 2

1. Sheep liver fluke (biliary fluke)
2. sheep
3. prominent cephalic cone. small oral and ventral suckers.

Question 3

What is the life cycle/ pathogenesis of fasciola hepatica?

Answer 3

(sheep liver fluke)
eggs get into water and hatch —becomes miricardium in water penetrates SNAIL—Cercaria comes out of snail and is free swimming—changes to metacaria (via plants or sheep?)—human (host) ingest metacaria— host poops out eggs to start cycle again.

Question 4

What are the symptoms of fasciola hepatica?

Answer 4

(sheep liver fluke)

gallstones. biliary obstruction. increased bilirubin in blood. Untreated can lead to cirrhosis.

Question 5

What is another name for Clonorchis sinensis? How is it transmitted?

Answer 5

1. Chinese liver fluke

2. undercooked fish (life cycle similar to sheep liver fluke, but uses fish instead of sheep)

Question 6

Where do adult Clonorchis sinensis live? And what symptoms does cause?

Answer 6

(Chinese liver fluke)

1. intrahepatic biliary ducts
2. RUQ pain. jaundice. hepatosplenomegaly.
   * (complication= adenomatous hyperplasia. Cholangiocarcinoma)*

Question 7

What is another name for Paragonimus Westermani? What is unique about it?

Answer 7

1. lung fluke

2. egg has operculum

Question 8

What are the symptoms/complications of Paragonimus westermani?

Answer 8

(lung fluke)

• adult forms get encapsulated in granuloma= TB-like.
• if cysts rupture= cough/chest pain.
• cerebral paragonimiasis= headaches/fever/nausea/visual disturbances/convulsive seizures.