Also called auxillary host
or transport host
. A species in which a parasite
may survive longer than it would outside any host, but which is not necessary to the parasite's life cycle
, and in which no significant development occurs. This usually means that a paratenic host supplies nourishment
to the parasite, but does not enable it to multiply or develop to a different stage. In some cases, the parasite gets the opportunity to reenter its normal life cycle from the paratenic host, but most of the time it's a dead end
For example, humans can act as paratenic hosts to dog roundworm by ingesting eggs (which contain already fully-developed larvae) contained in infested dogs' feces. The larvae can hatch, survive and migrate in the human body, but do not develop further, although they do cause toxocariasis. If a thusly infected human were eaten by suitable regular host animals, the larvae could complete their life cycle there.