Parasitology (block two) Flashcards
(22 cards)
facultative parasite
may become parasitic but does not require a host
not a true parasite - parasites require a host
opportunistic infection
an infection caused by pathogens that take advantage of an opportunity not normally available
ex: a host with a weakened immune system
parasitism
when an organism for all or part of its life derive at least some but often all of it’s food from a living organism of another species
One who eats at another’s table
ectoparasite
lives on the outside of the host
endoparasite
lives on the inside of a host
phoresis
the act of being carried
commensalism
host neither benefits nor is harmed
mutualism
symbiosis - long term
beneficial to both
key concepts of parasites
live in or on host (endo/ecto)
smaller than host
reduce host biological fitness to some extent
do parasites typically kill their hosts
no - they need a place to live
do parasites reproduce at a faster rate than their host
yes
how do parasites use their host for survival
food, water, heat, habitat, transmission
mode of infection
oral
skin penetration
injection
transplacental (vertical transmission)
Intermediate host (IH)
required
temporary but necessary host
continued development
paratenic host (PH) / transport host
non-required
no development
aberrant or abnormal host
host not usually used by parasite
development is slow and incomplete
dead-end or incidental host
prevents life cycle
prevents transmission to host
Definitive host (DH)
sexual reproduction takes place
host specific vs broad host spectrum
specific - parasite can only use that host
broad - parasite can use more than one host
direct life cycle
one host required to complete life cycle
parasites without an intermediate host
Indirect life cycle
two or more hosts
involves stages in the hosts and the environment
cats can only get parasites via transplacental
False
only dogs
