Visceral Flukes Flashcards
- best studied Trematode
- Adults reside in gall bladder and bile duct in liver
- leaf shaped, cephalic cone at anterior end
Fasciola hepatica
__is a common parasite of sheep and cattle kept on damp pastures worldwide but is only occasionally found in humans
Fasciola hepatica
Fasciola hepatica
Cause of infection?
Symptoms?
Treatment and control?
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
-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?
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
Eggs are___ by snail for Clonorchis sinensis?
Ingested
You gotta know the 4 major diffeerences between Fasciolopsis Buski and Fasciola hepatica
- Caeca lack side branches in F. buski
- The ventral sucker is much larger than the oral sucker in F. buski
- No cephalic cone for F. buski
- Adults live in small intestine NOT liver
____is the largest trematode
Fasciolopsis buski
How does infection by Fasciolopsis buski occur?
ingestion of metacercaria encysted on freshwater plants commonly freshwater chestnuts and bamboo shoots. Ingested raw
What are resrvoir host of F. buski?
pigs, dogs, rabbits
What are control and preventative measures of F. buski?
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
___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
Echinostoma revolutum
What are symptoms of Echinostomiasis?
Echinostomiasis is caused by Echinostoma revolutum
Symptoms include: inflammation and mild ulceration, with darrhea and abdominal pain, and anemia
What is the treatment and control of Echinostoma revolutum?
Treatment is Praziquantel, there are so many primary and secondary host of E. revolutum that control is impossible
How are humans commonly infected with E. revolutum?
by eating raw mussels or snails that have metacercariae in them
What is the preferred secondary host of Heterophyes heterophyes?
Mullet
What is the preferred secondary host of Metagonimus yokagawai
salmon
Describe the pathology of Metagonimus yokagawai and Heterophyes heterophyes
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
Give life cycle of Heterophyes and Metagonimus yokagawai (7 steps)
- Eggs passed in host feces
- Eggs ingested by 1st intermediate host (snail)
- Parasite reproduces ASEXUALLY, cercariae are liberated
- Cercariae penetrate skin of 2nd intermediate host:
- M yokagawai Salmon
- H. heterophyes Mullet - Cercariae encyst, form metacercariae
- Definitive host is infected
- Adult worms found in host small intestine
The adult worm of this parasite looks like a coffee bean because it is reddish brown
Paragonimus westermani
___was first described after 2 Royal bengal tigers died in zoo in Europe in 1878
Paragonimus westermani
__is found i lungs, brain, and viscera of Japanese, Korean, Indian, Philipino humans
Paragonimus westermani
The cercariae tail of this parasite are useless, they crawl to crab and crayfish to infect
P. westermani
How are humans infected with P. westermani?
Infected by eating undercooked crustaceans, worms excyst in duodenum and remain there. Then penetrate diaphragm and pleura and enter bronchioles of lungs AHHHHHHH
What are symptoms of infection of P. westermani?
Adult worms in lungs cause dry cough, chest pain, dyspnea, fever, hemopytysis.
In the brain can produce seizures
What is the diagnostic tool and treatment of P. westermani infection?
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
