External and Internal
Infestations can be classified as either external or internal with regards to the parasites' location in relation to the host.
An external ectoparasitic infestation is a condition in which organisms live primarily on the surface of the host (though Porocephaliasis can penetrate viscerally) and includes those involving mites, ticks, and head lice.
An internal endoparasitic infestation is a condition in which organisms live within the host and includes those involving worms (though swimmer's itch stays near the surface).
Medically, the term infestation is often reserved only for external ectoparasitic infestations while the term infection refers to internal endoparasitic conditions.
Read more about this topic: Infestation
Famous quotes containing the words external and/or internal:
“The burning of rebellious thoughts in the little breast, of internal hatred and opposition, could not long go on without slight whiffs of external smoke, such as mark the course of subterranean fire.”
—Harriet Beecher Stowe (1811–1896)
“I have been amazed by the Anglo-Saxon’s lack of curiosity about the internal lives and emotions of the Negroes, and for that matter, any non-Anglo-Saxon peoples within our borders, above the class of unskilled labor.”
—Zora Neale Hurston (1891–1960)