Trematodes

Question 1

What is the morphology of trematodes (flukes)?

Answer 1

Flat worms with two suckers

Question 2

What is the reproductive modality of trematodes (flukes)?

Answer 2

Hermaphrodites (except schistosomes)

Question 3

What intermediate host is shared by all trematodes (flukes)?

Answer 3

Snails

Question 4

Trematodes all have what three life stages

Answer 4

Miracidia - leaves egg, enters snail, Cercaria - leaves snail infects humans, Eggs - all have operculum except schistosomes

Question 5

What are the four categories of trematodes based on where they live?

Answer 5

Intestinal, Hepatic, Pulmonary, and Blood (Schistosomes) Trematodes

Question 6

What type of trematode is fasciolopsis buski?

Answer 6

An intestinal trematode (lives in duodenum or jejunum)

Question 7

Where do fasciolopsis buski eggs encyst?

Answer 7

Aquatic vegetation (bamboo shoots, water chestnuts)

Question 8

Symptoms of fasciolopsis buski infection

Answer 8

Abdominal pain, diarrhea

Question 9

What type of trematode is fasciola hepatica and where does it live?

Answer 9

A hepatic treamtode, lives in bile ducts and gall bladder

Question 10

How do fasciola hepatic get their eggs into the feces?

Answer 10

Through the common bile duct to the intestine

Question 11

Symptoms of fasciola hepatic infection

Answer 11

Eosinophilia, abdominal pain, fever, hepatomegaly, biliary colic, jaundice. Later, macrocytic anemia, inflammation of gall bladder, gallstones

Question 12

How do humans usually acquire fasciola hepatic infection?

Answer 12

Ingestion of fresh watercress (but who can live without fresh watercress?)

Question 13

What type of trematode is clonorchis sinensis and where does it live?

Answer 13

Hepatic trematode (also called Chinese liver fluke), lives in bile passages

Question 14

How do humans acquire clonorchis sinensis infection?

Answer 14

Eating infected fresh water fish

Question 15

Symptoms of clonorchis sinensis infection

Answer 15

Liver dysfunction and gall bladder dysfunction

Question 16

What two factors have made clonorchis sinensis infection very difficult to control?

Answer 16

Fertilzation of commercial fishponds with human feces (ew) and the fact that human infections persist for 50 years

Question 17

What type of trematode is paragonimus westermani and where does it live?

Answer 17

Pulmonary trematode, lives in fibrous capsules in the lungs

Question 18

How do paragonimus westermani eggs get into the feces?

Answer 18

Coughed up and swallowed

Question 19

Where do paragonimus westermani cercariae encyst?

Answer 19

Fresh water crabs or crayfish soft tissues

Question 20

How do ingested paragonimus westermani cysts get to the lungs?

Answer 20

Migrate through intestinal wall to peritoneal cavity and then through diaphragm to lung

Question 21

Symptoms of paragonimus westermani infection

Answer 21

Ranges from 1) occasional cough to dyspnea, 2) fever, anorexia and pulmonary abcess, 3) pneumonia. Also convulsions and seizures in 1 pct of cases

Question 22

What can be seen on a chest x-ray in the case of paragonimus westermani infection?

Answer 22

Infiltrates and cysts

Question 23

Four ways schistosomes are different from other trematodes

Answer 23

1) Cercariae initiate infection by skin penetration, 2) Are males and females (not hermaphroditic), 3) Cylindrical, 4) Eggs have spines rather than operculum

Question 24

What type of trematode is schistosoma japonicum and where does it live?

Answer 24

Blood trematode (schistosome), lives in mesenteric vein of small intestine

Question 25

How do infecting schistosoma japonicum cercariae get to where they live as adults?

Answer 25

Penetrate cutaneous capillaries and migrate to the mesenteric vein by route which includes heart, lung and liver

Question 26

Symptoms of schistosoma japonicum infection

Answer 26

Skin rash. Acute - fever, diarrhea, epigastric distress, hepatosplenomegaly, anemia, dysentery. Chronic - liver fibrosis, granulomas in liver, intestinal fibrosis, ascites, intestinal andor hepatic dysfunction with cerebral involvement

Question 27

What is the diagnostic method for trematode infections and what is the one exception to this?

Answer 27

All diagnosed by finding eggs in feces except schistosoma haematobium which is diagnosed by finding eggs in urine

Question 28

Schistosoma mansoni is essential identical clinically to what other trematode and what is one difference?

Answer 28

Schistosoma japonicum. Mansoni is humans-only

Question 29

What type of trematode is schistosoma haematobium and where do they live?

Answer 29

Blood trematode (schistosome). Live in blood vessels of the urinary bladder (release eggs in urine)

Question 30

How do infecting schistosoma haematobium cercaria get to where they live as adults?

Answer 30

Penetrate skin, BVs to lungs, portal blood, inferior mesenteric vein and rectal vessels to vesical, prostatic or uterine plexus |S s p748

Question 31

Symptoms of schistosoma haematobium infection

Answer 31

Hematuria, anemia, uremia, bladder failure

Question 32

There is a correlation between schistosoma haematobium infection and what condition?

Answer 32

Squamous cell carcinoma of the bladder