Parasites In Humans
Find The Nastiest Parasites In Humans

Fasciolopsis Buski - Intestinal Fluke

Fasciolopsis buski is the largest intestinal fluke in humans. It causes a parasitic disease called fasciolopsiasis and is commonly known as the giant intestinal fluke. Fasciolopsiasis is endemic in China, India, Malaysia, South-East Asia and Taiwan, especially in areas, where pigs are raised and fed with freshwater plants. According to some estimates there are over 10 million infected people in East Asia.

The life cycle of Fasciolopsis buski starts, when immature, unembryonated eggs are released into the intestine and stool of an infected human. If the feces end up in warm water (27–32 °C), the eggs become embryonated within two weeks and larvae called miracidia hatch after seven weeks. The miracidia find freshwater snails (the intermediate hosts) and penetrate their skin. In the snail the parasites develop and go through several larval stages: sporocysts, rediae, and cercariae. The cercariae exit the snail and encyst into metacercariae on aquatic, edible plants. If a human (or a pig) ingests water or raw vegetation contaminated with the cysts, the metacercariae excyst in the small intestine and attach to the intestinal wall. They develop into adults within three months. They feed on intestinal contents and live about one year. In large infestations they inhabit most of the gastrointestinal tract (starting from the stomach). Mature adults are hermaphroditic (having both male and female reproductive organs) and produce over 25,000 eggs per day.

Fasciolopsis buski life cycle

Minor infections are sometimes asymptomatic. Symptoms of heavy infections can include:

  • allergic reactions
  • anemia (pale skin etc.)
  • ascites (accumulation of fluid in the peritoneal cavity)
  • diarrhea
  • fever
  • obstruction of the bowel
  • stomach ache
  • swelling of the skin
  • toxemia (toxins in the bloodstream).

The diagnosis of Fasciolopsis buski is usually done by identifying eggs from a stool specimen under a microscope. Rarely adult flukes are found from the sample. Fasciolopsis buski and Fasciola hepatica have very similar eggs.

Fasciolopsiasis is treated with praziquantel following the advice of your health care provider. Other good drugs are mebendazole, thiabendazole, pyrantel pamoate, oxyclozanide, nitroxynil and hexachlorophene. Black walnut green hull is a good natural herb against adult worms whereas wormwood herb kills effectively larvae.

Freezing vegetables below -10 °C for a few days or heating them above 60 °C kills most parasites and their eggs. Drinking water can be filtered or boiled (in areas of poor sanitation). Additionally human or pig feces should not be used as a fertilizer in agriculture.

Fasciolopsis buski Adult, about 20–75 mm long and 8–20 mm wide, flat, leaf-shaped, blunt anterior end, undulating, tandem, dendritic testes, poorly-developed oral and ventral suckers, branched ovaries, vast vitelline follicles, can be distinguished from other fasciolids by a lack of cephalic cone or "shoulders" and the unbranched ceca.

Fasciolopsis buski egg Egg, yellow-brown, ellipsoidal, thin shell, operculated, filled with yolk cells, microscopic, about 130–160 micrometers (µm) long and 70–90 µm wide.