BIOSTATS

EPIDEMIOLOGY

upon, befall

epi (means

study of

logy (means

people, population, man

demo (means

antibiotic

a substance produced by or a semisynthetic substance derived from

a microorganism and stable in dilute solution to inhibit or kill another

microorganism.

disease

a pattern of response by a living organism to some form of invasion by

a foreign substance or injury which causes an alteration of the organisms

normal functioning.

endemic

the ongoing, usual level of, or constant presence of a disease in a

given population.

epidemic

outbreak or occurrence of one specific disease from a single source,

in a group population, community, or geographical area, in excess of the

usual level of expectancy.

etiology

the factors contributing to the source of or causation or a disease

holoendemic

a disease that is highly prevalent in a population and is

commonly acquired early in life in most of the children of the population.

hyperendemic

persistent level of activity beyond or above the expected

prevalence.

incidence

the extent that people, within a population who do not have the

disease, develop the disease during a specific time period. It measures the rate of new cases of a disease.

infective disease

are those which the pathogen or agent has the capability to

enter, survive, and multiply in the host.

invasiveness

the ability to get into a susceptible host and cause a disease

within the host.

pandemic

epidemic that is widespread across a country, continent, or large

populace, possible worldwide.

pathogens

organisms or substances such as bacteria, viruses, or parasites

that are capable of producing diseases.

pathogenesis

the development, production, or process of generating a disease.

pathogenic

disease causing or producing.

pathogenicity

describes the potential ability and strength of a pathogenic

substance to cause disease.

point prevalence

how many cases of a disease exist in a group of people at

that moment. It relies on two factors: number of people with the disease in

the past and duration of the disease.

prevalence

the number of people within a population who have a certain

disease at a given point in time.

toxins

a poisonous substance that is a specific product of the metabolic

activities of a living organism and is usually very unstable.

virulence

the extent of pathogenicity or strength of different organisms.

host (who) agent(what) environment (where)

the three in epidemiology triangle

agent

this is usually pathogen (virus, bacterium, parasite or other microbes.

This also includes chemical or physical causes of disease or injury.

host

this is the organism who is exposed to and harbor a disease.

environment

this refers to any extrinsic factors that can influence exposure and

susceptibility.