Handout 1 Flashcards
ANIMAL PARASITE
Uni- or multicellular organism, which - constantly or temporarely - lives on or in a different species for feeding and/or reproduction, while making harm to the latter.
We can differentiate between ecto- and endoparasites according to their location outside or inside the host, respectively.
(FINAL) HOST
Higher organism, on which or in which a parasite species occurs, or finds suitable conditions to reach full (sexual) maturity. The ‘final host’ (or definitive host) term is relevant to the life cycle of those parasites, which also have intermediate host.
INTERMEDIATE HOST
An animal species, in which a (sexually) immature (infectious) stage of the parasite can develop, and which is necessary for the completion of the parasite’s life cycle.
PARATENIC HOST (RESERVOIR)
An organism, in which the infectious larvae (or developmental stages) stay alive and accumulate, therefore prolonging the lifespan of the larvae and promoting the infection of the final host, but which is not obligatory for the completion of the parasite’s life cycle.
VECTOR
An organism spreading the parasite either by carrying it (as a mechanical vector) or also making suitable conditions for its development (as a biological vector, necessary for the parasite to complete its life cycle).
SPECIFIC HOST
Host species suitable for the establishment of the parasite. a. Ordinary host: in its normal physiological conditions.
b. Occasional host: only when predisposing factors make it possible.
STENOXENOUS PARASITE
It can only establish in one (or very closely related) host species.
EURYXENOUS PARASITE
It can infect a wider range of host species.
HOMOXENOUS PARASITE
Parasite, of which the life cycle involves one host species.
HETEROXENOUS PARASITE
Parasite, of which the life cycle involves more than one host species.
HOST RANGE
The range of those species, in which the (sexually) mature stage of a given parasite can develop.
INERMEDIATE-HOST RANGE
The range of those species, in which the (sexually) immature stages can develop.
HOST SUSCEPTIBILITY
Consists of those factors, which make a host species suitable for the establishment of the given parasite.
BREED (INNATE or GENETIC) RESISTANCE
The genetic insurability of a certain species/breed/ strain/individual for the establishment of the given parasite.
AGE RESISTANCE
The host species is susceptible for its specific parasite only when young.
ACQUIRED IMMUNOLOGICAL UNRESPONSIVENESS
When the host species is unable to mount a successful immune response against the parasite (because it became tolerant to the antigenic parasite derivants at an early age, these being recognized as self).
INFECTIVE IMMUNITY (PREMONITION)
Acquired immunity, which necessitates the presence of the parasite for its sustenance.
ACQUIRED IMMUNITY
Specific defence mechanism against the parasite evoked by its antigenic substances (which frequently results only in a partial protection against homologous reinfection).
INVASION (INFESTATION)
The entering of the parasite into (onto) the host species.
a. Active: when the parasite actively invades the host by migration, contact or retroinfection (this latter from
the same individual).
b. Passive: when the parasite is taken up by the host with the forage, water, air or (sexual) contact. This also
might involve transmitters (instruments, iatrogenic intervention, etc.).
INFECTION BY VECTORS
The higher organism transmits (inoculates or carries) the parasite into or onto the host.
PRENATAL (TRANSPLACENTAL) INFECTION -
When a certain stage of the parasite can infect the foetus of the pregnant host via the placental circulation.
COLOSTRAL OR GALACTOGENIC INFECTION -
the parasites are taken up by the suckling via the colostrum or milk of its mother.
HORIZONTAL INFECTION
Spreading of the parasite between individuals within the same generation.
VERTICAL INFECTION
Spreading of the parasite between individuals of different generations.
PHORESY
The phenomenon, when a parasite is carried onto another host by attachment to a different (typically flying) species.
DIRECT DEVELOPMENT
Only one host (or also paratenic host) is involved in the life cycle of the parasite.
INDIRECT DEVELOPMENT
Besides the final host one or two intermediate hosts are also necessary for the parasite to complete its life cycle.
DEVELOPMENTAL STAGES (INSTARS)
Forms in the development of the parasite that are separated by moults or ways of proliferation.
DEVELOPMENTAL PERIODS
Certain part of the development defined in terms of time, a. Embryonal period (in case of nematodes): from the zygote to the first stage larva (LI), b: Postembryonic period (PE): from the LI to the adult (A), sexually matureparasite.
PEL from LI to the infectious larval stage (usually L3).
PE2: from the infectious larval stage (entering the host) to A.
ARRESTED LARVAL DEVELOPMENT (HYPOBIOSIS)
Suspended PE2 of (nematode) larvae in (mainly connective and muscle) tissues of their host (prolonged or interrupted according to such conditions, as the immune status of the host, seasonality, etc.), usually followed by reactivation and resumption of development.
HISTOTROPIC PHASE
That part of the development of nematode larvae, which takes place in the wall (mucous membrane) of the gastrointestinal tract of their host. It is irregular, if the larvae suspend then- development (regularly returning to the intestinal lumen after one or two moults).
HEPATIC-TRACHEAL (ENTEROHEPATOPULMONARY) MIGRATORY ROUTE
From the intestine through the portal vein, liver, heart, a. pulmonalis, then the alveoli and trachea back to the intestine.
LUNG TRAVEL (PASSAGE)
Through the intact skin or (oropharyngeal) mucosa towards the lungs and finally into the intestine.
OVIPAROUS NEMATODES
Females of which are laying eggs containing a zygote.
OVOVIVIPAROUS NEMATODES
Females of which are laying eggs containing a segmented stage or LI (still inside the egg shell).
VIVIPAROUS NEMATODES
Those laying free LI.
PUPIPAROUS FLIES
Which are laying larvae ready to pupate.
DIRECT
food withdrawal, blood meal, mechanical and toxic effects, disturbing.
INDIRECT
proliferation, inflammation, immunpathological reactions.
PARASITOSIS
The state of the host or intermediate host resulting from the infection by the parasite. It can be clinical (with clinical signs, i. e. symptoms) or subclinical. This latter means an equilibrium between host and parasite, which can, however, aggravate into clinically manifesting disease according to predisposing factors (i.e. winter-housing, crowding, shearing, etc.).
PARASITOZOONOSIS
Parasitic infection spreading from animals to humans.
ANTHROPOZOONOSIS
Infection spreading from man to animals.
PRAEPATENT PERIOD
Time lapse from the infection of the host until the first appearance of the parasite’s sexual products (oocysts, eggs) e.g. in the faeces.
PATENT PERIOD
Time lapse, during which the sexual products of the parasite are being shed.
LATENT INFECTION
When the presence of the parasite doesn’t involve detectable signs.
POPULATION
Individuals of the same species having certain common characteristics.
INFRAPOPULATION
All mature and immature parasites of the same species located in or on one host individual.
SUPRAPOPULATION
Sum of the infrapopulations of a parasitic species in or on all the host individuals within an ecosystem.
POPULATION DYNAMICS
Changing of the number of individuals, their age, proportion of sexes, etc. in time within a population.
GRADATION
Fast and massive multiplication of the individuals of a certain species within a defined area.
EXTENSITY OF INFECTIONS (PREVALENCE)
Percentage of parasite-infested individuals in a stock examined.
E(%)=(infected / examined) x 100
INTENSITY OF INFECTIONS
The degree of infection with a parasitic species examined in a host individual (or group), which is calculated on the basis of parasite number (i.e. size of infrapopulation).
THERAPY
Taking mearures in order to preserve or restore the health of an animal (group). It consists of hygienic and nutritional steps as well as application of antiparasitic drug(s). The latter can serve therapeutic (curative) or preventive aims according to whether the parasites are already present or are sound to occur.
DEHELMINTISATION
Removal of helminths with anthelmintics.
PRAEIMAGINAL TREATMENT
It aims at killing the parasites before they reach sexual maturity.
IMAGINAL TREATMENT
It aims at killing the adult parasites.
TACTICAL CONTROL
Measures to reduce the formation of massive infectious sources at biologically predictable time in order to assure parasite-free environment (pasture, stable, etc.) or to prevent the introduction of the parasites (quarantine, preliminary examination, preventive treatment, etc.).
STRATEGIC CONTROL
To treat the animals in order to eliminate their infection at time(s) calculated on the basis of seasonality and biology of the given parasite.
EXTENSEFFICACY (EE)
A percentage to demonstrate the efficacy of treatment on the basis of numeral reduction of infected hosts.
EE(%)=[(N-n)/N]xlO0
where N is the number of infected animals in the control group
and n is the number of infected animals in the treated group after treatment.
INTENSEFFICACY (IE)
A percentage to demonstrate the efficacy of treatment on the basis of reduction in the degree of infection of the hosts.
IE(%)=[(N-n)/N]xlOO
where N is the number of parasites (or their products) present in control animals and n is the number of parasites in treated animals after treatment.
ADULTICIDE, OVICIDE or LARVICIDE TREATMENT
Terms relating to the stage, which is affected by the antiparasitic drug.
DEVASTATION (ERADICATION)
A complex system of treatments (preventive and curative) and regulations (mechanical, chemical, physical and biological means) in order to kill all developmental stages of the parasite that are present (devastation is more relevant to the parasites, whereas eradication also refers to the disease caused by them).
