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 fi living together of unlike organisms fi Symbiosis fi fi 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 fi fi Pre-patent period