Host (infectious diseases)

A host in the context of infectious disease refers to an animal or plant that acts as a biological refuge in which another - often parasitic - organism may dwell. The host usually provides shelter or nourishment to the other organism, which may use the host to partially/completely sexually develop .

Non-parasitic relationships are seen, for example in humans the commensal organisms of the gut (microbiome).

Types of hosts

• accidental host
  • a host that shelters an organism which does not usually parasitize that host
• incidental host (a.k.a. dead-end host)
  • a host that shelters an organism but is unable to transmit the organism to a different host
• primary host (a.k.a. definitive/final host)
  • a host in which an organism partially/completely sexually develops
• reservoir host
  • a host that shelters an organism without harm to itself