Fasciolopsiasis

Fasciolopsiasis results from infection by the trematode Fasciolopsis buski (Lankester, 1857) Odhner, 1902, the largest intestinal fluke of humans (up to 7.5 cm in length).

Geographic distribution
This disease occurs in Asia and the Indian subcontinent, especially in areas where humans raise pigs and consume raw aquatic plants.

Infection cycle
The parasite infects an amphibic snail (Segmentina nitidella, Segmentina hemisphaerula, Hippeutis schmackerie, Gyraulus, Lymnaea, Pila, Planorbis (Indoplanorbis)) after released by infected feces; from this intermediate host metacercaria infest on aquatic plants, which are eaten (raw) by pigs and humans. Also the water is possibly infective when drunk unheated ("Encysted cercariae exist not only on aquatic plants, but also on the surface of the water.".)

Clinical features
Most infections are light and asymptomatic. In heavier infections, symptoms include diarrhea, abdominal pain, fever, ascites, anasarca, and intestinal obstruction.

Laboratory diagnosis
Microscopic identification of eggs, or more rarely of the adult flukes, in the stool or vomitus is the basis of specific diagnosis. The eggs are indistinguishable from those of Fasciola hepatica.

Treatment
Praziquantel is the drug of choice for treatment of fasciolopsiasis.

Incidence/prevalence

 * "It has been estimated that there may be 10 million people in East Asia infected with this fluke, yet its radiological identification remains unreported."