Parasitology: Introduction Flashcards
What is a parasite?
an animal or plant which lives in or upon another organism and draws its nutrients directly from it.
For this course, what does parasitology cover?
EUKARYOTES
- arthropods
- helminths
- protozoa
What is the importance of the veterinarian in Parasitology?
- diagnosis
- understanding what different factors contribute to disease
- identify what can be done to best prevent recurrence of shift in imbalance that gave parasites the advantage
What is an integrated Parasite Management System
A method of controlling parasites in animal populations by using a combination of chemical and non-chemical methods. It relies on the veterinarian to understand why an animal got sick, what factors contributed to the disease, and what can be done to prevent it from happening again.
What is an endoparasite?
an internal parasite
What is an ectoparasite?
an external parasite
What is the difference between an infestation and an infection?
an infection involves an endoparasite
an infestation involves an ectoparasite
What is infection?
the establishment and sometimes multiplication of organisms in body tissues
What is infectious?
caused by or capable of being communicated by infection
What is infective?
a form or stage of a parasite that is capable of production infection.
T/F: Many parasites are able to cause infection as soon as they invade a host.
False
T/F: Many parasites are not able to cause infection until after some period of development in the environment
True
What is the Life Cycle?
The whole history of a parasite
- can be either simple or complex
What is a complex life cycle?
also known as an indirect life cycle, it involves more than one host
What is a simple life cycle?
also known as a direct life cycle, it involves one host
What is a definitive host?
the final host, where sexual multiplication occurs
What is an intermediate host?
A required host for an immature stage of parasite. The immature parasite must go through this host before it can go on to the final host.
What is a paratenic host?
a host of an immature parasite stage that is not an obligatory part of the life cycle
What is a normal host?
an animal recognized as part of the normal parasite cycle
what is an abnormal or aberrant host?
an animal that is not normally a host.
- often, but not always associated with disease
T/F: an abnormal host can only be a final host.
False
an abnormal host can be an abnormal definitive, intermediate, or transport host. It depends on where in the life cycle the parasite is.
What is a reservoir host?
a host that serves as a source of infection for other animals
What is a vector?
an invertebrate, often an arthropod, that transmits infectious disease
What is a mechanical vector?
a vector that simply carries the pathogen from one host to another, and is not important to pathogenic development
What is a biological Vector?
a vector that a pathogen develops in before it is transferred to a host.
T/F: Prepatent periods are used with external parasites.
False
PPP is used for internal parasites
What is the Prepatent Period
the time required following infection of the definitive host to reach reproductive maturity
- from infection to just before production of eggs/cysts within a definitive host
T/F: Prepatent Period is the same as generation time.
False
Generation time is from egg to egg
What is the importance of the prepatent period?
an animal may be infected with parasites, but we cannot diagnose it because there are no eggs in the fecal samples for us to use as a diagnostic test.
T/F: You must capitalize both genus and species when giving the scientific name.
False
ONLY CAPITALIZE THE SPECIES
T/F: You must underline the genus and species when handwriting the name
true
T/F: Parasites usually require an appropriate stimulus/stimuli to recognize their potential host
True
T/F: Intracellular parasites need specific receptors on cells of appropriate hosts
True
T/F: Host response does not play a role in parasite infection
False, both acquired and innate immunity play roles
What are some examples of innate immunity to parasites
- physical barriers
- chemical barriers
- cellular barriers
Which part of acquired immunity is dominant in mature responses to multicellular parasites?
Th2 components
- eosinophilia is considered a marker for helminth infection
What kind of acquired immune response is Th1 typically dominant in?
intracellular protozoan parasite responses
Does normal immunity completely eliminate infection?
no
Normal immunity typically limits, but does not eliminate infections
- it can limit reinfection and reduce growth and repro of parasites. Often full expression of immunity requires presence of an active infection.
T/F: Vaccines are a wonderful tool for parasite prevention
False, vaccines don’t do shit.
What is the 70-30 Rule of parasites?
70% of the parasites are in 30% of the animals.
- most animals have few parasites, few animals have many parasties
T/F: Parasitic infection =/= disease
true
T/F: Immunity often prevents both disease and infestation/infection
false
immunity often prevents disease but not infection/infestation
Are young animals usually more or less susceptible to disease than adults?
more
T/F: Parasties that must develop and survive in the environment are at the mercy of the weather
true
