Entamoeba polecki is a single-celled parasite that is found in intestines, mainly in pigs and monkeys. Other animals that it can be found in are cattle, goats, sheep, dogs, and humans. The way humans get infected is by swallowing the parasite. The parasite is sometimes confused with Entamoeba histolytica. The parasite was discovered in 1912 in Czechoslovakia by Von Prowazek.