Paratenic host 'In parasitology, the term paratenic describes a host that is not necessary for the development of a particular species of parasite, but nonetheless may happen to serve to maintain the life cycle of that parasite' until they are transferred to an obligatory host. (from Wikipedia and Parasitology: A Conceptual Approach book) Reservoir host Reservoir hosts are such animals which accumulate in themselves the invasive larvae of the helminthes and contribute to their transfer to the definitive host, not being however an obligatory condition for the complition of parasite ontogenesis. (from Proceedings of the First International Congress of Parasitology: Roma, 21-26 September 1964) The source however says that Reservoir host is same as paratenic host which contradicts other sources (like General Parasitology by Cheng) which says: Reservoir host is an animal that becomes infected and serve as a source from which other animals can be infected. (the only difference I presume is that it may or may not be obligatory) In many other books (book 1 & 2) a parallel definition is mentioned that a reservoir host is a host that harbors parasite until their transmission to human beings. This inturn brings forth another question, is a reservoir host a biological vector then? So the question : Are paratenic host and reservoir host same or different? P.S. I don't know what the standard books on parasitology are which could have solved this issue. Reference to one such book will be really appreciated.