INTRODUCTION Flashcards
(40 cards)
living together of phylogenetically different organsims (e.g. host and parasite)
symbiosis
beneficial to both organisms (++)
mutualism
beneficial to one organism, neutral to other
commensalism
beneficial to one organism, harmful to other
parasitism
composition of epidemiologic triangle
host, agent, environment
harbors adult and sexual stage of parasite
definitive host
definitive host of T. gondii
cat (sexual stage occurs in the cat’s intestine)
definitive host of Plasmodium spp.
mosquito
harbors larval or asexual stage
intermediate host
intermediate host of trematodes
snail (all trematodes have snail as intermediate host)
accidental IH of Echinococcus spp.
man
harbors parasite that does not develop but remains alive and is infective to the next host
paratenic host
paratenic host of D. latum
large fish
paratenic host of G. spinigerum
bird and snake
allows the parasite’s life cycle to continue and serves as the source of human infection
reservoir host
reservoir host of Balantidium coli
pig
depends entirely to the host for existence
obligate parasites
capable of parasitic and free living existence
facultative parasites
examples of facultative parasites
S. stercoralis & Free Living Amoebas (Naegleria and Acanthamoeba spp.)
Larval stage is passed in a host while the adult is free living
Transitory parasite
Example of transitory parasite
Strongyloides stercoralis in indirect cycle
Completes its life cycle in one host
Permanent parasite
Parasite with one host
Monoxenous/Homoxenous
Example of permanent parasite
Hymenolepis nana in direct cycle