introduction to parasitology
keywords
commensalism
two species living together
no metabolic dependance
symbiosis
two species living together
each dependant on each other
parasitism
two species living together
parasite at the expense of host
major parasite groups
arthropods
protozoa
helminths (worms)
cestodes (tapeworms)
trematodes (flukes)
nematodes (roundworms)
insects
acarina
single celled organisms
involves:
nutritional dependance
immunological defence (constant tug of war)
integration of life-cycles
microparasites & macroparasite
microparasites
eg. protozoa
multiplies inside hosts
macroparasites
eg. helminths
do not multiply in the parasite
have effects on
pathogenesis
immunology
epidemiology
chemotherapy/treatment plan
importance in vet med
parasites can cause
death
overt clinical disease
sub-clinical disease
can detect, but not many symptoms
causes less than optimum productivity
the bottom of the iceberg
parasite life cycle in general
1. locate host
detection of heat, light, CO2, vibration
1a. survive (if no host)
2. invade another host
ingestion - faeces, cannibalism, plants etc
inoculation - infection by parasite with smaller parasites
skin penetration - eg. blood fluke, hookworm
3. multiply
increased number of offspring = high chance of survival
can be inside or outside host
3a. if poor conditions outside
can become dormant and reemerge in better weather conditions