title: Variations in pathogenicity of parasites due to man's interference. Introduction to the discussion.
mesh_terms: D000562:Amebiasis / Q000469:parasitology / Q000635:transmission*; D000656:Amoeba / Q000472:pathogenicity*; D004463:Ecology; D005243:Feces / Q000469:parasitology; D006801:Humans; D007422:Intestines / Q000469:parasitology; D014876:Water Pollution