Parasites live in other host organisms and depend on them for survival. Parasites that can affect humans include ticks, lice, and hookworms. Symptoms of a parasite infection in humans can... Parasitic infections are diseases caused by organisms that live off of your body’s nutrients. Fever, fatigue, diarrhea and vomiting are common symptoms. Learn about parasites , tiny organisms that can live inside or on the human body, causing various diseases. Find out how to prevent, diagnose and treat parasitic infections with antiparasitic medications and natural remedies. A parasite is a plant or an animal that lives on, or with, or inside a larger species extracting nutrients. In some cases, the parasite can harm the host and in other situations, it is completely harmless. There are three types of parasites namely ectoparasites, endoparasites and mesoparasites. Ectoparasites include parasites that survive outside the host and induce itching and rashes in that area. Endoparasites include parasites that survive inside the body of the host, usually in the ...