Skip to Main Content

The large intestinal fluke, Fasciolopsis buski, is a common parasite of pigs and humans in eastern and southern Asia. Eggs shed in stools hatch in freshwater, followed by infection of snails, and release of cercariae that encyst on aquatic plants. Humans are infected by eating uncooked plants, including water chestnuts, bamboo shoots, and watercress. Adult flukes mature in about 3 months and live in the small intestine attached to the mucosa, leading to local inflammation and ulceration. Other intestinal flukes that cause similar syndromes include Heterophyes (North Africa and Turkey) and Metagonimus (East Asia) species; these species are transmitted by undercooked freshwater fish.

Infections with intestinal flukes are often asymptomatic, although eosinophilia may be marked. In symptomatic cases, after an incubation period of 1–2 months, manifestations include epigastric pain and diarrhea. Other gastrointestinal symptoms, ileus, edema, and ascites may be seen uncommonly. Diagnosis is based on identification of characteristic eggs or adult flukes in the stool. In contrast to other fluke infections, illness more than 6 months after travel in an endemic area is unlikely. The drug of choice is praziquantel, 25 mg/kg orally as a single dose. Alternative therapies are triclabendazole and niclosamide (for most species).

Fischer  PU  et al. North American paragonimiasis: epidemiology and diagnostic strategies. Expert Rev Anti Infect Ther. 2015;13:779.
[PubMed: 25835312]  
Mas-Coma  S  et al. Fascioliasis. Adv Exp Med Biol. 2019;1154:71.
[PubMed: 31297760]  
Na  BK  et al. Clonorchis sinensis and clonorchiasis. Acta Trop. 2019:105309.
[PubMed: 31862466]

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.