the aggregate of parasites that live in a single organ, in interconnected organs, or in an entire animal or human. The concept of a parasite biocenosis was introduced by the Soviet scientist E. N. Pavlovskii. A parasite biocenosis may include parasitic animals, as well as parasitic bacteria, fungi, and viruses; these organisms are included regardless of their pathogenicity. The species composition of a parasite biocenosis varies considerably from host to host, even among hosts of a single species.
In order to understand the complex interrelationships that exist in the parasite biocenosis as a whole and between the biocenosis’ constituents and the host, the participating parasite species must be fully identified. Such knowledge is useful in understanding the parasite carrier state and the nature of parasitic and infectious diseases; it also is the basis for selecting effective methods for preventing and treating such diseases.