Main » Infectious diseases » Snail-mediated Helminthiases » Fasciolopsiasis
F. buski is limited to areas of the Far East. In certain localities, eg Northeast Thailand, almost the entire population of some villages may be infected.
Distribution of Fasciolopsis buski.
Photo 1. Egg of F. buski. Miracidia hatching from eggs passed in the faeces after shedding their ciliated coats, invade snails of various genera including Segmentina and Hippeutis. The reproductive cycle in the snail differs from that of the schistosomes. After development through the sporocysts and two generations of rediae, cercaria emerge into the water. They then encyst on aquatic plants such as the water caltrop and water chestnut. (x200)
Photo 2. Metacercaria of F. buski. The metacercaria of F. buski with its cyst wall. (X200)
Photo 3. Living segmentina hemisphaerula.
Photo 4. Adult F. buski. The adult F. buski is the largest parasitic trematode of man and may reach 7.5 cm in length. The pig is the main animal reservoir of infection for man. (Natural size)
Photo 5. The water caltrop.
'Plantations' of water caltrop are harvested in endemic areas. The characteristic fruits of this plant are commonly eaten raw, and the metacercariae are thus swallowed. In the digestive tract they attach to the mucosa of the upper part of the small intestine where they mature. Water chestnuts commonly spread infection to children who peel the raw plants with their teeth, thus ingesting the attached metacercariae.
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» Schistosoma haematobium
» Schistosoma japonicum
» Schistosomes Found Uncommonly in Man
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» Liver fluke infections
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