INTRODUCTION TO

EPIDEMIOLOGY

MR.J.C.FRANKLIN Asst.professor

DEFINITION:Epidemiology is derived from Greek word

“epidemic”

EPI – up onDEMOS – peopleLOGOS – study

Epidemiology means the study of disease in human population.

DEFINITION

“EPIDEMIOLOGY IS DEFINED AS THE

STUDY OF THE DISTRIBUTION AND

DETERMINANTS OF HEALTH RELATED STATES

OR EVENTS IN SPECIFIED POPULATIONS AND

THE APPLICATION OF THIS STUDY TO CONTROL

THE HEALTH PROBLEMS”.

- LAST-

HISTORY OF EPIDEMIOLOGY

ADAM AND EVE

HIPPOCRATES

FLORENCE NIGHTINGALE

CONCEPT OF EPIDEMIOLOGY

PLATO AND ROUSEAU:

“FAULT OF HUMAN LUXUARY”

HIPPOCRATES:“ENVIRONMENTAL INFLUENCES”

LOUIS PASTEUR“INFECTIOUS DISEASES”

IBN KHATIMA:“SMALL MINUTE BODIES”

AIMS OF EPIDEMIOLOGY

AIMS:TO DESCRIBE THE DISTRIBUTION AND SIZE

OF DISEASE PROBLEMS IN HUMAN

POPULATION.

TO IDENTIFY THE AETIOLOGICAL FACTORS.

TO PROVIDE THE DATA ESSENTIAL TO THE

PLANNING, IMPLEMENTATION AND

EVALUATION.

SCOPE OF EPIDEMIOLOGY

ACCORDING TO DISEASE GROUP

INFECTIOUS DISEASE EPIDEIOLOGY

CARDIO VASCULAR EPIDEMIOLOGY

CANCER EPIDEMIOLOGY

ACCORDING TO GROUP OF FACTORSNUTRITIVE EPIDEMIOLOGY

REPRODUCTIVE EPIDEMIOLOGY

ENVIRONMENTAL EPIDEMIOLOGY

CLINICAL EPIDEMIOLOGY

MOLECULAR EPIDEMIOLOGY

GENETIC EPIDEMIOLOGY

COMPUTATIONAL EPIDEMIOLOGY

USES OF

EPIDEMIOLOGY

Search of cause / causes of diseases

Helps to describe the health status of population

Helps to discover and bridge gaps in natural history of diseases.

Helps in controlling diseasesHelps in better management of

health services

1. IDENTIFY THE CAUSES OF DISEASES.

2. HELPS TO DESCRIBE THE HEALTH STATUS OF THE

POPULATION.

3.TO CONTROL THE DISEASE TRANSMISSION.

4.PLANNING, IMPLEMENTING AND EVALUATING HEALTH PROGRAMMES

ON EVIDENCE BASIS.

TERMINOLOGIES USEDIN

EPIDEMIOLOGY

INFECTION:

The entry and development or multiplication of an infectious agent in the body of man or animal.

ENDEMICThe constant presence of a disease or

infectious agent within a given geographical area or population group, without importation from outside. Eg. Common cold.

EPIDEMIC AN OUT BREAK OF

DISEASE IN A

COMMUNITY IN

EXCESS OF NORMAL

EXPECTATION AND

DERIVED FROM A

COMMON OR

PROPAGATED SOURCE.

SPORADIC

The cases occurs

irregularly, haphazardly

from time to time and

generally infrequently.

E.g.. Polio

PANDEMICAn epidemic

which spreads

from country to

country or over

the whole world.

Eg. AIDS

ZOONOSESDiseases or

infections which are

naturally transmitted

between vertebrate

animals and men.

eg. Rabies, plague

INCUBATION PERIOD

This is the time interval

between the entry of the

disease agent into the

body and the appearance

of first sign and

symptom of the disease.

CARRIER

A person who

harbors the disease

agent without having

any outward signs

and symptoms.

ISOLATIONA separation of a

person with

infectious disease

from contact with

other human beings

for the period of

communicability.

PATHOGENICITY

Ability to cause

the disease.

CONTAGIOUS

A disease that is

transmitted through

contact.

Eg. STD and Leprosy.

RESERVOIRThe habitat ( place

for living) where an

infectious agent

living, grows and

multiplies.

VIRULENCE

Measure the severity

of disease.

FOMITES

Inanimate articles

other than food or

water contaminated

by the infectious

discharges.

VECTORUsually an arthropod

eg. Mosquito which

transfers an

infectious agent from

an infected person to

a healthy person.

CONCLUSIONINTRODUCTION

HISTORY

DEFINITION

AIMS

SCOPE

USES

TERMINOLOGIES