Epidemiology - 2nd year B.Sc Nursing

1. ANANDGOWDA.S
ASSISTANT PROFESSOR
COMMUNITY HEALTH NURSING
YENEPOYA NURSING COLLEGE
YENEPOYA UNIVERSITY ,
MANGALURU

2.  Epidemiology is derived from the Greek word
Meaning –
Epi -------among
Demos---People
Logos –---study
It means epidemiology is the study of
diseases/events occur among people.
Epidemiology is the study of disease in
populations.

3.  Epidemiology is that branch of medical science which
deals with epidemics. (Parkin)
 Epidemiology is the study of disease, any disease, as a
mass phenomenon. (Greenwood)

4. According to JOHN M. LAST (1988)
The study of frequency,
distribution and determinants of
health related states or events in
specified populations, and the
application of this study to the
control of health problems.

5.  The term Frequency refers to the magnitude of health
related states or events in a defined community.
 The term Distribution refers to occurrence of health
related states or events in terms of persons, place and
time in a defined community.
 The term Determinants refer to etiological factors
causing health related states or events in a defined
community.

6. AIMS OF EPIDEMIOLOGY
According to the International Epidemiological
Association (IEA), epidemiology has three main aims :
1. to describe the distribution and magnitude of health
and disease problems in human populations
2. to identify aetiological factors (risk factors) in the
pathogenesis of disease and

7. 3. to provide the data essential to the planning,
implementation and evaluation of services for the
prevention, control and treatment of disease and to the
setting up of priorities among those services.
The ultimate aim of epidemiology is to lead to effective
action:
 to eliminate or reduce the health problem or its
consequences
 to promote the health and well-being of society as a whole

8. SCOPE OF EPIDIMIOLOGY
1. Epidemiology has very wide scope, wider than what
is normally conceives. Besides communicable & non-
communicable diseases. The field of epidemiology
covers all other health –related states and events
such as alcoholism, drug abuse, accidents divorces,
migrations etc.,

9. 2. Epidemiology studies the distribution of
health related states and events. The
distribution is viewed in three
epidemiological dimensions of time, place
and person.

10. 3. Epidemiology studies the determinants of health
related states and events. These determinants are
identified by observing the distribution pattern of
diseases and verifying cause-effect relationships.

11.  Epidemiology finds application in the control of health
problems. Having identified the determinants and their
cause-effect relationships, epidemiological principles
guide the formulation of appropriate interventional
strategies for the prevention and control of health
problems

13. USES OF EPIDEMIOLOGY
1. To reduce historically the rise and fall of disease in the
populations
2. Community diagnosis
3. Planning and evaluation
4. Evaluation of individual’s risk and chances
5. Syndrome identification
6. Completing the natural history of diseases
7. Searching for causes and risk factors

14. TERMINOLOGIES USED IN EPIDEMIOLOGY
 INFECTION
The entry and development or multiplication of
an infectious agent in the body of man or animals.
CONTAMINATION
The presence of an infectious agent on a body
surface, also on or in clothes, beddings, toys, surgical
instruments or dressings, other inanimate articles or
substances including water, milk and food

15. INFESTATION
For persons or animals the lodgement, development and
reproduction of arthropods on the surface of the body
or in the clothing.
E.g- lice, itch mite
HOST
A person or other animal, including birds and
arthropods, that affords subsistence or lodgement to
an infectious agent under natural condition.

16. INFECTIOUS DISEASE
 A clinically manifest disease of man or animals
resulting from an infection.
CONTAGIOUS DISEASE
A disease that is transmitted through contact.
E.g- Scabies, trachoma, STD and leprosy

17. COMMUNICABLE DISEASE
 An illness due to a specific infectious agent or its toxic
products capable of being directly or indirectly transmitted
from man to man, animal to animal, or from the
environment ( air, dust, soil, water, food etc) to man or
animal.
 EPIDEMIC-
(Epi –upon, demos-people)
Epidemic is the rapid spread of a disease in a
specific area or among a certain population
group.
E.g-Measles, chicken pox , cholera and non-
communicable diseases (CHD, lung cancer)

18. ENDEMIC
(En-in , Demos-people)
It refers to the constant presence of a disease or infectious agent
within a given geographic area or population group.
E.g- Common cold, hepatitis A, typhoid fever.
SPORADIC –
The sporadic means scattered about. The cases occur irregularly,
haphazardly from time to time and generally infrequently.
E.g- Polio , tetanus, herpes zoster and meningococcal meningitis.

19. PANDEMIC
 Pandemic is a worldwide epidemic; an epidemic
occurring over a wide geographic area such as a section
of a nation, the entire nation, a continent or the world.
and affecting a large number of people.
E.g- Influenza , cholera and acute hemorrhagic
conjunctivitis

20. EXOTIC
 Disease which are imported into a country in which they do
not otherwise occur.
E.g- Rabies in UK
ZOONOSES
An infection or infectious disease transmissible
under natural conditions from vertebrate to
man.
E.g- Rabies, plague, anthrax, brucellosis,
salmonellosis , endemic typhus

21. EPIZOOTIC
 An outbreak (epidemic) of disease in an animal
population.
E.g- Antharx, brucellosis, rabies, influenza etc.
EPORNITHIC
An outbreak ( epidemic) of disease in a bird
population.
E.g- Bird flu

22. ENZOOTIC
 An endemic occurring in animals.
E.g- Anthrax, rabies, brucellosis etc.
NOSOCOMIAL INFECTION
Nosocomial (hospital acquired) infection is an
infection originating in a patient while in a hospital or
other health care facility.
E.g- hepatitis B and Urinary tract infections

23. OPPORTUNISTIC INFECTION
 This is infection by an organism that takes the
opportunity provided by a defect in host defence to
infect the host and hence cause disease.
E.g- Herpes simplex, cytomegalovirus, toxoplasma,
M.Tuberculosis
Opportunistic infection very common in AIDS.

24. IATROGENIC (PHYSICIAN-INDUCED) DISEASE
 Any untoward or adverse consequence of a preventive,
diagnostic or therapeutic regimen or procedure, that
causes impairment, handicap, disability or death
resulting from a physician’s professional activity or
from the professional activity of other health
professionals.
E.g- childhood leukaemia due to prenatal X-rays,
hepatitis B following blood transfusion.