Dientamoeba fragilis is a member of the flagellate genus. This parasite is single-celled, and can be found in the gastrointestinal tract of humans, pigs, and gorillas. While D. fragilis is of flagellate ancestry, it possesses no flagellum of its own, likely having lost this characteristic over evolutionary time. Interestingly, this parasite lacks a cyst stage, and exists exclusively as a trophozoite.
Life CycleEditDientamoeba fragilis is ingested as a trophozoite and remains in this stage throughout its entire life cycle. Following ingestion, the parasite travels to the large intestine where it replicates by binary fission. Trophozoites are then released in the feces. This life cycle is often referred to as the fecal-oral route.
Dientamoeba fragilis infection can be symptomatic or asymptomatic. Symptoms occur within 1 to 2 weeks after infection, and primarily include diarrhea and abdominal pain. This parasite is not believed to cause mortality, and safe and effetive treatments are available.