Epidemiology

(Definition)

الوابئياتعمل تعريف

At the end of this presentation the attendant is

expected to:

Define Epidemiology.

Identify the main issues in the definition.

Discuss the uses of Epidemiology.

12/17/2014

Historical Aspects

“Father of medicine”

Who in his Observations on Airs, Water and Places first suggested that:

human disease might be related to man’s environment.

Hippocrates

(BC 460-377)

An acute observervation of

natural history of disease,

Hippocrates recognised

epidemics as mass

phenomena.

He also:

differentiated between

epidemic and endemic disease.

Hippocrates

NEXT STORY: John Snow &

Cholera

Snow conducted his

classic study in

1854 when an

epidemic of cholera

developed in the

Golden Square of

London.

He began his investigation

by determining in

this area persons with

cholera lived and worked.

He then used

this information

to map the

distribution of

cases on what

epidemiologists

call a spot map

Because Snow

believed that water

was a source of

infection for

cholera, he marked

the location of

water pumps on

his spot map,

then looked for a

relationship

between the

distribution of

cholera case

households and

the location of

pumps.

He noticed

that more case

households

clustered

around Pump

A,

he concluded

that the pump

A was the most

likely source of

infection.

Story continue…

- The risk of death from cholera was

more than 5 times higher in districts

served only by the Southwark and

Vauxhall Company than in those

served only by the Lambeth

Company.

Some of Significant words

Definition

of

EpidemiologyDefinition of

Epidemiology

Epidemiology is derived from the Greek,

Epi: On or upon.

Demos: people.

Logos : the study of

Epidemiology is the basic science

of Public Health

Epidemiology has been defined by John M

Last in 1988 as:

“ The study of the distribution and

determinants of health related states or

events in specified populations, and the

application of this study to the control of

health problems”

Two main areas are involved in the

Previous definition:

I. Study of the distribution of disease or health

status in the human population

Descriptive Epidemiology

Magnitude +Trend

sof

Health related

events

Measure

II. study of the determinants or

underlying causes of disease.

Analytical Epidemiology

Two main areas are involved in the

Previous definition:

F A C T O R

Aims of

Epidemiology

Broadly, epidemiology has three main

aims:

I. To describe the

distribution and

size of disease

problems in

human

populations.

Broadly, epidemiology has three main

aims:

II. To identify

aetiological

factors (or risk

factors) in the

pathogenesis

of disease.

III. To provide the data essential to:

Broadly, epidemiology has three main aims:

Planning Implementatio

n

Evaluation

Health services ( Prevention , control and

treatment of disease)

• Setting up of priorities among those

services