Figure 1

Figure 1. Adult Fasciolopsis buski fluke. Source: DPDx (https://www.cdc.gov/dpdx).

Figure 2

Figure 2. Photograph of George Busk, for whom Fasciolopsis buski is named. Source: Wellcome Library, London, UK.

The intestinal fluke Fasciolopsis buski is the largest trematode that parasitizes humans, reaching up to 75 mm in length (Figure 1). The genus Fasciolopsis was established by Arthur Looss in 1899 and the term derived from the Latin word fasciola, meaning small band, and the Ancient Greek suffix -ὄψῐς (-opsis), meaning resemblance, referring to the similarity with the members of the genus Fasciola. The species was named for the English surgeon George Busk (Figure 2), who identified the adult worm in 1852 from the duodenum of a sailor from India. The first comprehensive description of the species was provided by Edwin Lankester in 1857, and the parasite’s lifecycle was definitively clarified by Koan Nakagawa in 1921.

Fasciolopsiasis is a foodborne trematodiasis that is endemic in rural areas of South and Southeast Asia. The parasite affects both humans and pigs, and pigs act as the main zoonotic reservoir for the parasite. The cercariae, released into the water by various species of planorbid snails, encyst on underwater vegetation. Infection occurs via ingestion of metacercariae on the surface of the water or encysted on freshwater edible plants.