Fasciolopsis buski : Epidemiology, Laboratory Diagnosis & Treatment

Fasciolopsis buski commonly called large or giant intestinal fluke causing Fasciolopsiasis. It was first describe by Buski in 1843 in the duodenum of an East Indian sailor. It is found worldwide but limited to particularly in areas in which sheep and cattle are raised such as parts of china, Taiwan, Thailand, Vietnam, India and Indonesia.

Reservoir

• Rabbits
• Pigs
• Dogs

Intermediate Host

•  Snail 

Definitive Host

• Human

Fasciolopsis buski mode of transmission

Through the ingestion of raw, uncooked or poorly cooked and encysted vegetation containing metacercariae such as

• water chestnut
• lotus
• water caltrop
• bamboo, and other edible plants

Morphology

Life cycle

• The primary reservoir for the intestinal fluke is the pig. Dogs may also harbor the parasite
• The adult worm resides in the duodenum or jejunum and has a lifespan of about 6 months.
• Eggs are laid in the lumen of the intestine in large numbers, about 25,000 per day.
• These eggs are then passed in feces which hatch in water in about 6 weeks, releasing the miracidia which swim about.
• Once the miracidia are in contact with a suitable mulluscan intermediate host such as snails of the genus Segmentina, they penetrate its tissues to undergo development in the next few weeks as sporocyst, first and second generation rediae and cercariae.
• The cercariae which escape from the snail encyst on the roots of the lotus, bulb of the water chestnut and on other aquatic vegetation.
• When they are eaten, the metacercariae excyst in the duodenum, become attached to the mucosa and develop into adults in about 3 months

Pathogenicity of Fasciolopsis

The pathogenesis of fasciolopsiasis is due to traumatic, mechanical and toxic effects.  The Larvae that attaches to the duodenal and jejunal mucosa cause inflammation and local ulceration. The adult worms may also cause partial obstruction of the bowel in heavy infections. Intoxication and sensitization also account for clinical illness

Clinical Symptoms

• Diarrhea
• Abdominal pain.
• Allergic
• Oedema
• Anemia
• Ascites
• Prostration
• Jaundice

Laboratory Diagnosis

• For the fasciolopsis buski diagnosis, The specimen choice for recovery of the eggs of F. buski is stool for microscopic examination for the presence of fasciolopsis buski eggs.
• Because the eggs are indistinguishable, information regarding patient symptoms and travel history is necessary to diagnose the causative species.
• Speciation may also be accomplished by recovery of the adult Fasciolopsis worm.
• Other methodologies available for the detection of Fasciola include the Enterotest, ELISA, and gel diffusion.

Treatment

• Praziquantel
• niclosamide
• Hexylresorcinol
• Tetrachlorethylene

Prevention and Control

• Proper human fecal disposal and sanitation practices, particularly in areas in which animal reservoir hosts reside
• Controlling the snail population using molluscide
• Avoiding the consumption of raw water plants or contaminated water.

Reference

• Fasciolopsis, Wikipedia
• Fasciolopsis, CDC
• Fasciolopsis, Textbook of Medical Parasitology BY CK Jayaram Paniker