Fasciolopsiasis is a disease caused by the largest intestinal flatworm, trematode Fasciolopsis buski. The disease is endemic in the Far East and Southeast Asia. Human acquires the infection after eating raw freshwater plants contaminated with the infective metacercariae. The adult worms, 2–7.5 cm (0.8–3 inches) long, attach themselves to the tissues of the small intestine of the host by means of ventral suckers; the sites of attachment may later ulcerate and form abscesses. In the early stage of the infection, there is usually abdominal pain, as well as diarrhea and nausea alternating with constipation.
Heavy infestations that go untreated cause general body weakness and fluid retention, which may have serious consequences, especially in children. Infection in humans is usually contracted following ingestion of uncooked aquatic plants containing cysts of the worm larvae. A simple but effective preventive measure is the immersion of aquatic foods in boiling water. F. buski is endemic in Asia including China, Taiwan, South-East Asia, Indonesia, Malaysia and India. It has a prevalence of up to 60% in India and mainland China and has an estimated 10 million human infections.Infections occur most often in school-age children or in impoverished areas with a lack of proper sanitation systems.
While most cases of Fasciolopsiasis are asymptomatic or very short lasting, severe infections can cause intestinal obstruction, abdominal pain, ascites, fever, diarrhea, and anasarca. Diagnosis of Fasciolopsiasis requires microscopy to identify the eggs of the flatworm. Stool samples can also be used or vomitus. The eggs are identical to those of the Fasciola hepatica and may require further testing.
Treatment for Fasciolopsiasis requires the prescription medications Praziquantel as the preferred choice. Treatment Praziquantel is the drug of choice for treatment. Treatment is effective in early or light infections. Heavy infections are more difficult to treat. Studies of the effectiveness of various drugs for treatment of children with F. buski have shown tetrachloroethylene as capable of reducing faecal egg counts by up to 99%. Other anthelmintics that can be used include thiabendazole, mebendazole, levamisole and pyrantel pamoate. oxyclozanide, hexachlorophene and nitroxynil are also highly effective.