Parasite Habitats or Mode of Development

• Endoparasite - a parasite that lives inside the body of its host
• Ectoparasite - a parasite that lives on the surface or outside of the body of its host
• Pediculosis - an infestation with the human head-and-body louse
• Obligate parasite - needs a host at some stage of their life cycle to complete their development and to propagate their species
• Facultative parasite - may exist in a free-living state or may become parasitic when the need arises
• Accidental or incidental parasite - parasite that establishes itself in a host where it does not ordinarily live
• Permanent parasite - remains on or in the body of the host for its entire life
• Temporary parasite - lives and feeds on the host only for a short period of time
• Definitive host - where the parasite attains sexual maturity
• Intermediate host - where the parasite undergoes larval development but does not reach sexual maturity; it only harbors the asexual or larval stage of the parasite
• Reservoir host - animals that harbor an infection that can be transmitted to humans; responsible for the zoonotic transmission of infection
• Paratenic host - where the parasite does not develop further to later stages, yet it still remains alive and infective to another host; widens parasite distribution
• Wild boar - paratenic host for transferring the infective stage of Paragonimus westermani to humans
• Dogs and water buffaloes - examples of reservoir hosts for Schistosoma japonicum
• Zoonotic transmission of infection - transmission of infection between humans and animals
• Oncomelania hupensis quadrasi snail - intermediate host for Schistosoma japonicum
• Humans - definitive host of Taenia sp.
• Schistosoma sp. - example of permanent parasite
• Hymenolepis diminuta (rat tapeworm) and Echinococcus granulosus (hydatid tapeworm) - examples of accidental parasites
• Naegleria fowleri and Acanthamoeba - examples of facultative parasites
• Taenia saginata (beef tapeworm) and Taenia solium (pork tapeworm) - examples of obligate parasites
• Pediculus humanus capitis (head louse) and Pediculus humanus humanus (body louse) - examples of ectoparasites
• Arthropods - attack the exterior surface of the host, examples of ectoparasites
• Infestation - presence of an ectoparasite in the host
• A parasite is considered erratic when it is found in an organ that is not its usual habitat.
• Infection - presence of an endoparasite in the host