Commensalism
two species live together and one bene ts without harming or bene ting the other
e.g. Entamoeba coli
Mutualism
two organisms mutually bene t from each other
e.g Termites and Flagellates
Parasitism
the parasite lives in or on another for its survival at the expense of the host
e.g. Entamoeba histolytica
Endoparasite
parasite living inside the body of a host; causes infection
Ectoparasite
parasite living outside the body of a host; causes infestation
Erratic parasite
when parasite is found in an organ which is not its usual habitat
Obligate Parasite
need a host to complete their development; dependent on host
Facultative Parasite
can exist in a free living state or become parasitic when needed
Accidental/Incidental
Parasite
parasite that establishes itself in a host where it does not ordinarily live
Permanent Parasite
remains on or in the body of the host for its entire life
Temporary parasite
lives in host for a short period of time
Spurious parasite
free living organism; does not cause infection
De nitive/Final Host
parasite attains sexual maturity
Intermediate host
asexual or larval stage of parasite
Paratenic Host
parasite does not develop further but it remains alive and able to infect another
host
Reservoir Host
allow the parasite’s life cycle to continue and become additional sources of
infection
Vectors
responsible for transmitting the parasite from one host to another
Biologic Vector
transmits the parasite only after development
Mechanical/Phoretic Vector
transports the parasite
Carrier
harbors the parasite without manifestations
Exposure
process of inoculation of infective agent
Infection
establishment of the infective agent in the host
Incubation period
aka Clinical Incubation Period
period between infection and evidence of symptoms
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living together of unlike organisms
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Symbiosis
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DEFINITION OF TERMS
aka Biologic Incubation Period
period between infection/acquisition of the parasite and evidence or
demonstration of infection
Autoinfection
infected individual becomes his own direct source of infection
Superinfection/
Hyperinfection
already infected individual is further infected with the same species leading to
massive infection
Epidemiology
study of patterns, distribution, and occurrence of disease
Incidence
number of new cases of infection
Prevalence
number of individuals infected with a particular parasite
Cumulative prevalence
percentage of individuals in a population infected with at least one parasite
Intensity of infection
burden of infection related to the number of worms per infected person
Morbidity
clinical consequences of infections or diseases
Deworming
use of anthelminthic drugs in an individual
Cure rate
number of previously positive subjects found to be egg neg on examination
ERR
Egg Reduction Rate
percentage fall in egg counts after deworming
Selective treatment
individual level deworming with selection for treatment
Targeted treatment
group level deworming where the group to be treated may be de ned
Universal Treatment
population level deworming
Preventive Chemotherapy
intervention involving the administration of drug/s to reduce morbidity and
transmission
Coverage
proportion of the target population reached by an intervention
Ef cacy
effect of a drug against an infective agent
Effectiveness
measure of the effect of a drug against an infective agent
Drug Resistance
genetically transmitted loss of susceptibility to a drug in a parasite population
Morbidity Control
avoidance of illness caused by infections
IEC
information-education-communication
health education strategy that aims to encourage people to adapt and maintain
healthy life practices
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Pre-patent period