Intermediate Host Definition

The interaction between the different organisms and their association makes some of them benefitting mutually, while some parasitically and others either as competitors, commensalism or amensalism. In all these relationship, there is a host which resides within organism, providing all the nutrition and fulfilling all the requirements.

The host in commensalism, mutualism and parasitism provides 3 things to be precise, which are niche i.e habitat, nutrition and nest to lay its egg. Hosts are of 5 types and they are primary host, secondary host, paratenic host, accidental host and reservoir host. The intermediate hosts are the secondary hosts.

The intermediate host reside in the non-sexual parasite phases, whereas the primary host resides in sexual phase of the parasite. As secondary host are the intermediate host, similarly primary host are also called as definitive host.

In intermediate it’s the site for asexual reproduction of parasite, whereas in primary host it is the sexual reproduction site for parasites. In intermediate, parasite resides for a small period within the host, whereas in primary host, it stays for a longer time. Within the host, gametes combines and zygote is produced in primary host, which is not seen in intermediate host.

Examples of intermediate host are mosquitos and humans, whereas dog, humans, female anopheles mosquitos are the host in primary, whereas the parasite is plasmodium, wucheria bancrofti, lymphatic filariasis and others.