Visceral Flukes

Question 1

• best studied Trematode
• Adults reside in gall bladder and bile duct in liver
• leaf shaped, cephalic cone at anterior end

Answer 1

Fasciola hepatica

Question 2

__is a common parasite of sheep and cattle kept on damp pastures worldwide but is only occasionally found in humans

Answer 2

Fasciola hepatica

Question 3

Fasciola hepatica
Cause of infection?
Symptoms?
Treatment and control?

Answer 3

Disease: fascioliasis
Cause: Larva migrating to bile ducts leads to intense eosinophilic inflammation to the hepatic parenchyma. In the bile duct, Fasciola hepatica larva cause hyperplasia of biliary epithelium, and hardening of biliary wall ducts.
Treatment: Administration orally of bithionol and praziquantel 2 weeks
Control Dont allow sheep and cattle feces near aquatic regions

Question 4

-Location of infection: Japan, China, Korea, Vietnam
Reservoir host: cats, dogs, tigers, foxes
1st intermediate host: snail
2nd intermediate host: freshwater fish (carp)
Eggs partially embryonated when passed in feces
Source of infection: humans eating raw or undercooked fish
Symptoms of infection: diarrhea, hepatomegaly, jaundice
Treatment?
Diagnosis?
Disease name?
Prevetion/Control?

Answer 4

Clonorchis sinensis
Disease name: Clonorchiasis
Treatment: PRaziquantel taken orally for 2 days
Diagnosis: recovery of characteristic eggs
Prevention/control: treatment of feces before using as a fertilizer

Question 5

Eggs are___ by snail for Clonorchis sinensis?

Answer 5

Ingested

Question 6

You gotta know the 4 major diffeerences between Fasciolopsis Buski and Fasciola hepatica

Answer 6

1. Caeca lack side branches in F. buski
2. The ventral sucker is much larger than the oral sucker in F. buski
3. No cephalic cone for F. buski
4. Adults live in small intestine NOT liver

Question 7

____is the largest trematode

Answer 7

Fasciolopsis buski

Question 8

How does infection by Fasciolopsis buski occur?

Answer 8

ingestion of metacercaria encysted on freshwater plants commonly freshwater chestnuts and bamboo shoots. Ingested raw

Question 9

What are resrvoir host of F. buski?

Answer 9

pigs, dogs, rabbits

Question 10

What are control and preventative measures of F. buski?

Answer 10

Water vegetables should be carefully peeled and washed for prevention and control purposes. Boiling for a few minutes will kill the metacercaria cysts. Human feces should be treated before being used as fertilizer in ponds. Pig feces should be kept away from ponds. Pigs should not be fed freshwater plants without their being dried first

Question 11

___is recognized by its circumoral collar of peg-like spines.
It shows little host specifity,____will attack any bird or mammal that eats its metacercariae.
The circumoral collar has 37 spines in a double circle
Eggs are NON-embryonated
Metacercaria excyst in the small intestine where they become adults

Answer 11

Echinostoma revolutum

Question 12

What are symptoms of Echinostomiasis?

Answer 12

Echinostomiasis is caused by Echinostoma revolutum

Symptoms include: inflammation and mild ulceration, with darrhea and abdominal pain, and anemia

Question 13

What is the treatment and control of Echinostoma revolutum?

Answer 13

Treatment is Praziquantel, there are so many primary and secondary host of E. revolutum that control is impossible

Question 14

How are humans commonly infected with E. revolutum?

Answer 14

by eating raw mussels or snails that have metacercariae in them

Question 15

What is the preferred secondary host of Heterophyes heterophyes?

Answer 15

Mullet

Question 16

What is the preferred secondary host of Metagonimus yokagawai

Answer 16

salmon

Question 17

Describe the pathology of Metagonimus yokagawai and Heterophyes heterophyes

Answer 17

Pathology, Light infections are symptomless; heavy infections cause diarrhea and abdominal pain
Eggs sometimes enter the blood stream and carried to other sites in the body: heart, brain, and spinal cord are common target organs. Heart attacks and various neurological problems may also result

Question 18

Give life cycle of Heterophyes and Metagonimus yokagawai (7 steps)

Answer 18

1. Eggs passed in host feces
2. Eggs ingested by 1st intermediate host (snail)
3. Parasite reproduces ASEXUALLY, cercariae are liberated
4. Cercariae penetrate skin of 2nd intermediate host:
   - M yokagawai Salmon
   - H. heterophyes Mullet
5. Cercariae encyst, form metacercariae
6. Definitive host is infected
7. Adult worms found in host small intestine

Question 19

The adult worm of this parasite looks like a coffee bean because it is reddish brown

Answer 19

Paragonimus westermani

Question 20

___was first described after 2 Royal bengal tigers died in zoo in Europe in 1878

Answer 20

Paragonimus westermani

Question 21

__is found i lungs, brain, and viscera of Japanese, Korean, Indian, Philipino humans

Answer 21

Paragonimus westermani

Question 22

The cercariae tail of this parasite are useless, they crawl to crab and crayfish to infect

Answer 22

P. westermani

Question 23

How are humans infected with P. westermani?

Answer 23

Infected by eating undercooked crustaceans, worms excyst in duodenum and remain there. Then penetrate diaphragm and pleura and enter bronchioles of lungs AHHHHHHH

Question 24

What are symptoms of infection of P. westermani?

Answer 24

Adult worms in lungs cause dry cough, chest pain, dyspnea, fever, hemopytysis.
In the brain can produce seizures

Question 25

What is the diagnostic tool and treatment of P. westermani infection?

Answer 25

Eggs found in rust-colored sputum is the most reliable diagnostic tool
Praziquantel taken orally over 3 days is very effective with no side effects. For cerebral cases, surgery may be necessary