Humans often serve as hosts for many parasites, ranging from protozoans to worms. Examples of Parasitic Animals in Humans Plasmodium → causes malaria. Ascaris lumbricoides → roundworm infection. Taenia solium → pork tapeworm. Wuchereria bancrofti → filariasis (elephantiasis). Entamoeba histolytica → amoebiasis. Trichinella spiralis → trichinosis.