Parasites found in the human body include tapeworm, amoebas, trypanosoma and liver flukes, according to WebMD, the World Health Organization, and the Centers for Disease Control and Prevention. These parasites mostly enter the body through the bite of an insect or through contaminated food or water.
Tapeworms live in the intestines, and are flat worms whose bodies are divided into segments, says WebMD. There are six types of tapeworms that live in humans, and they are usually named for the animal whose undercooked flesh is consumed. These animals include cows, pigs and fish.
Amoebic dysentery is caused by an amoeba named Entamoeba histolytica, says WebMD. This parasite is also introduced into the body through contaminated water or food. The amoebae form cysts in the stomach that break open only when they reach the intestine. Then, the amoebae attack the walls of the intestines and cause them to ulcerate. Any cysts are passed out of the body with feces. They are still alive and able to infect other people.
Trypanosoma brucei gambiense and Trypanosoma brucei rhodesiense cause sleeping sickness, which is only found in subSaharan Africa, says the World Health Organization. Another species of trypanosome, Trypanosoma cruzi, causes Chagas disease, which occurs in the Americas.
Liver flukes, fasciola parasites, infect humans when they eat raw, freshwater plants such as watercress that have the parasite, says the CDC. Liver flukes are also ingested from water contaminated when these plants are washed. Two kinds of fasciola parasites infect humans.