Intermediate Host

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Related to intermediary host: paratenic host, reservoir host, final host

intermediate host

[‚in·tər′mēd·ē·ət ′hōst]
The host in which a parasite multiplies asexually.

Intermediate Host


(in biology). (1) An animal in which sexually immature parasites live. Those animals in which parasites reach sexual maturity and reproduce are called definitive hosts. Man, for instance, is the intermediate host of the causative agent of malaria (malarial plasmodium), while the mosquito is the definitive host.

(2) A plant on which a rust fungus, or a parasite of a cultivated plant, passes part of its life cycle. Most of these fungi form aecidial sporangiophores, or aecidia, on intermediate hosts; for example, stem rust of the grasses Puccinia graminis forms on barberry leaves.

References in periodicals archive ?
Also, for irrigation channels and other constructed waterways, building fast-flowing streams makes it more difficult for snails to survive, thus eliminating the intermediary host.
Since 1580, there have been 31 instances where new influenza viruses have emerged from their natural reservoir--wild aquatic birds--and through genetic reassortment in intermediary hosts such as pigs, have "jumped" to human populations with marked increases in human deaths.
The importance of molluscs in the global ecological niche is addressed from several angles, including parasitology, an area that has been overlooked despite the fact that these organisms are important intermediary hosts to parasites that afflict humans and other vertebrates.