Required Text Book:

Park's Textbook of
Preventive and Social
Medicine
27 th edi
• COMMUNITY MEDICINE :
A branch of medicine concerned with
the total health of the individual within
the home environment and in the community,
and with the application of comprehensive care to the prevention
and treatment of illness in the entire community.
1 Who is the father of community medicine or Preventive Medicine?
Richard Mead
2 What is considered community health?
Community health is a major field of study
within the medical and clinical sciences
which focuses on the maintenance, protection,
and improvement of the health status
of population groups and communities.
 • What is the difference between a family and a community?

Family is a group of people who are closely related to one another

by blood, by marriage or adoption and /or sharing the same house
hold.

Community refers to a collection of people in a geographical area

with a social structure.
• What is preventive and social medicine?

Preventive and social medicine is concerned with the

measures taken to prevent diseases and promote health.
Preventive and social medicine is also known as community medicine
& public health.
• What is the purpose of community health?

Community health services aim to improve

the health and wellbeing of local residents
by encouraging the people to actively participate
in their own health care.
Working together with other health related
sectors to provide coordinated care.
• What are the community health problems?

Examples : Adolescent pregnancy, access to clean drinking water,

child abuse and neglect, crime, domestic violence, drug abuse,
environmental contamination, ethnic conflict, health disparities,
hunger, inadequate emergency services, inequality, jobs, lack of
affordable housing, poverty, racism, etc.
Unhealthy communities lead to chronic disease, such as cancers,
diabetes, and heart disease.
Definition
Community:
The following definition is accepted by WHO ………

A community is a social group determined by geographical

boundaries and/or common values and interests.
Or,
Community can be as a collection of a group of persons in social
interaction in a geographical area and sharing a common social and
cultural life.
Characteristics:
1. The community is a contiguous geographical area.
2. It is composed of people living area.
3. People cooperate to satisfy their basic needs.
4. They are sharing the common organizations, e.g. markets, schools,
stores, banks, hospitals.
5. Specific functions or occupations as a whole for the community.
6. There should be a group of dependence or belongingness.
7. An interdependent behavior.
Definition: Community medicine
WHO technical committee (1972) defined community medicine as

“A system of delivery of comprehensive health care to the people by a

health team in order to improve health of the community”.

Comprehensive health care means----- Provision of preventive,

promotive , curative and rehabilitative health care to the people from
womb to the tomb to every individual residing in a defined geographic
area.
Objectives of community medicine:
1. To provide comprehensive health care (preventive, promotive ,
curative and rehabilitative).
2. To provide primary health care to the community.
3. To conduct epidemiological survey about common health problems.
4. To conduct health education programs among the people.
5. To participate the national health program; e.g. NID, TB, Malaria, DOT’S,
Kala-azar etc.
6. The final objective is to extend the scope of health disciplines
involved indirectly in health care. Such as economists, social
scientists.
 Community Medicine Clinical Medicine
Professionals go to the community. Patients go to the physician.

It is field oriented. It is hospital oriented.

Community diagnosis is done. Clinical diagnosis is done.

Teamwork is extremely necessary. Teamwork is needed only in a few occasions, e.g.

in an operation or in emergency management.

Field trial and surveys are very important. Only clinical trial is important.

Skill: Epidemiological skills are required. Skills: here technical skills are required.

Surveillance is needed for the control disease. Surveillance is not needed.

 Community Medicine Clinical Medicine

Treatment is done as part of prevention. Preventive care depends upon the clinical diagnosis
and to restore further complication.

Monitoring condition is poor. Monitoring condition is rich.

Special activities: During epidemic. Highest possible qualities of medical services to the
patients.
Public health:
The WHO expert committee adapting the definition of public health by C.E.A
Winslow (in 1920), has defined public health-----------
“The science and art of preventing disease, prolonging life, and promoting health and
efficiency through organized community efforts for
the sanitation of the environment, the control of communicable infections,
the education of the inividuals in personal hygiene, the organization of medical and nursing
services
for early diagnosis and preventive treatment of disease
and the development of social machinery
to ensure for every individual
a standard of living adequate for the maintenance of health,
so organizing these benefits
as to enable every citizen to realize his birthright of health and longevity”.
Father of public health:
An English epidemiologist John Snow studied the epidemiology of
cholera in London from 1848-1854 and established the role of polluted
drinking water in the spread of cholera.
The demand from people for clean water came after the study.
For this reason cholera is called the father of public health as the
principal activities of public health are improvement of sanitation and
to provide safe drinking water.
Public health emergency:
Any incidence which causes break down of public health by any means is
called public health emergency.
Public health emergency varies from country to country, according to the
socio-economic conditions of that country.
As for example, if a single case of cholera is found in USA that is the public
health emergency for USA but not for Bangladesh.
Examples:
• An epidemic outbreak.
• Natural calamities, i.e. cyclone, flood etc.
• Accidents e.g. serious road transport accident.
Basic human needs:
• Food
• Cloth
• Residence
• Education
• Medical support
Doctor Patient Relationship:
The doctor patient relationship is central to the practice of healthcare and is essential for the
delivery of high-quality health care in the diagnosis and treatment of disease. The doctor-
patient relationship forms one of the foundations of contemporary medical ethics.
For most physicians, the establishment of good rapport with a patient is important. Some
medical specialties, such as psychiatry and family medicine emphasize the physician-patient
relationship more than others, such as pathology or radiology.

Roles of doctors and patients for developing doctor-patient relationship are

described below-
Roles of Doctor:
1. A doctor must always keep in mind the importance of preserving
human life from the day of conception until death.
2. When some examinations and treatments are beyond his capacity,
he should summon another doctor who has the necessary ability.
3. A doctor should maintain absolute professional secrecy of the
patient.
4. A doctor must give necessary treatment in emergency
circumstances, unless he is certain that it can be given by others.
Roles of Patient:
1. A patient must have confidence in the competence of their
physician and must feel that they can confide in him or her.
2. He should furnish the doctor with complete information about past
illness, family history of diseases and the facts & circumstances of
his illness.
3. He should strictly follow the instructions of the doctor as regards
diet, medicine, mode of life etc.
4. He should pay a reasonable fee to the doctor.
Health
Definition:(WHO)
“Health is a state of complete physical, mental
and social wellbeing and not merely an absence of
disease or infirmity so that each citizen can lead
a socially and economically productive life.”
Infirmity:------
Physical or mental weakness .
esp. an unsound, unhealthy, or debilitated state;

Example:
limitation of vision in old age,
 Philosophy of health

* Health is a fundamental human right

*Health is the essence of productive life, and not the result of
ever increasing expenditure on medical care.
* Health is intersectoral.
* Health is an integral part of development.
* Health is central to the concept of quality of life.
*Health involves individuals, state and international
responsibility.
* Health and its maintaince is a major social investment.
* Health is world-wide social goal.
Changing concepts of health
1. Biomedical concept
2. Ecological concept
3. Psychosocial concept
4. Holistic concept
 Biomedical concept
►Traditionally health has been viewed
as an absence of disease.

e.g, free from disease was considered healthy.

It was based on the

“germ theory of disease".
The medical profession viewed
the human body as a machine,
disease as a consequence of the breakdown
of the machine and
One of the doctor’s task as repair of the machine.
► But this theory fails to address

the role of environment, social, psychological

► But this theory fails to address

the role of environment, social, psychological
and cultural determinants of health
e.g,
(malnutrition, chronic disease, accidents, drug
abuse, mental illness, environmental pollution,
population explosion)

, mental illness, environmental pollution, population

explosion)
cultural determinants of health e.g,(malnutrition, chronic disease, accidents, drug abuse, mental illness, environmental pollution, population explosion)
 Ecological concept

which viewed health

as a dynamic equilibrium.
The ecologists put forward an alternative
hypothesis
between man and his environment,
and disease is a maladjustment
of the human organism to environment.
Psychosocial concept
►Contemporary development in social
sciences revealed that health is not only
a biomedical phenomenon, but one
which is influenced by social,
psychological, cultural, economic and
political factors of the people concerned.
►These factors must be taken into
consideration in defining and measuring
health.
Holistic concept
►This is the synthesis of all the above concepts. It
recognizes the strength of social, economic,
political and environmental influences on health.
►This corresponds to the view held by the ancients
that health implies a sound mind in a sound body,
in a sound family, in sound environment.
• Health team--------
As the physicians as over worked professionally
To reduce their workeload an auxiliary worker group is need by giving
adequate training .
The WHO no longer uses the term "paramedical” for the various
professions allied with medicine.

Leader– doctor---nurse—social worker—health assistant—trained

dia—village health guide— other interested vollantiars---
Health is multidimensional.
 Dimensions of health
Physical Dimensions.
Mental Dimensions.
Social Dimensions.
Spiritual Dimensions.
Emotional Dimensions.
Vocational Dimensions.
Others Dimensions
Physical Dimensions.
►It implies the notion of “perfect functioning” of the body.
►The signs of physical health:
• A good complexion
• A clean skin
• Bright eyes
• Lustrous hair with a body well clothed with firm flesh
• Not too fat
• A sweet breath
• A good appetite
• Sound sleep
• Regular activity of bowels and bladder
• Smooth, easy, coordinated bodily movements
Mental Dimensions.
►A state of balance between the individual and the
surrounding world,
►a state of harmony between oneself and others,
►a coexistence between the realities of the self and
that of other people and that of the environment.
Characteristics of mentally healthy person:

Free from internal conflicts: he is not at war with himself.

He is well adjusted, he accepts critisim and is not easily upset.
He searches for identity
He has a strong sense of self-esteem
He knows himself (needs, problems &goals)
Good self- control, balances rationality & emotionality
Able to face problems, tries to solve intelligently .
Social Dimensions.

►It is the quantity and quality of an individual’s interpersonal ties and

the extent of involvement with the community. It includes----

• Social skills
• Social functioning
• Ability to be a member of a larger society
Spiritual Dimensions.
►That part of individual which strives for meaning and purpose in life.
It is intangible something. It includes----
• Integrity
• Principles
• Ethics
• Purpose in life
Emotional Dimensions.
►It relates to “feeling” where as mental health is “knowing” or
“cognition”.
Others Dimensions
Philosophical dimension
Cultural dimension
Socio-economic dimension
Environmental dimension
Educational dimension
Nutritional dimension
Curative dimension
Preventive dimension
Positive health
►It means perfect functioning of the body and mind.
It conceptualizes:
• Biologically- a state in which every cell and every organ
is functioning at optimum capacity and in perfect harmony
with the rest of the body.

• Psychologically- the individual feels a sense of perfect well-being.

• Socially- capacities for participation in social system are optimal.

 Prevention
Goals of prevention is--------
To promote health
To preserve health
To restore health when impaired
To minimize suffering and distress
Health promotion/ To promote Health
1. Health education
2. Environmental modifications
3. Nutritional interventions
4. Lifestyle and behavioral changes
Specific protection/ to preserve health
1. Immunization
2. Use of specific nutrients
3. Chemoprophylaxis
4. Protection against occupational hazards
5. Protection against accidents
6. Protection from carcinogens
7. Avoidance from allergens
8. Control of environmental pollutions
9. Control of quality of consumers products, foods, drugs, cosmetics.
Early diagnosis and treatment/ to restore
health when impaired
• The detection of disturbances of homoeostatic
and compensatory mechanism while
biochemical, morphological and functional
changes are still reversible.
eg TB, leprosy, STD, Ca cervix, cancer breast.
Disability limitation/ to minimize suffering and
distress
Impairment:
any loss or abnormality of psychological, physiological or anatomical structure or function.
eg. loss of foot in an accident.
Disability:
any restriction or lack of ability to perform an activity in the manner or within the range
considered normal for a human being.
Handicap:
a disadvantages for a given individual, resulting from an impairment or a disability, that
limits or even the fulfillment of a role that is normal for that individual.
Rehabilitation
• Medical rehabilitation: restoration of function
• Vocational rehabilitation: restoration of the capacity to earn a
livelihood
• Psychological rehabilitation: restoration of personal dignity and
confidence
Levels of prevention
1. Primordial prevention
2. Primary prevention
3. Secondary prevention
4. Tertiary prevention
Primordial prevention

A new concept particularly in the prevention of chronic

diseases.
It is the prevention of the development or emergence of risk
factors in population or countries in which they have not
yet appeared.
For example obesity , hypertention can be reduced by
changing the life style(e.g smoking, eating pattern, exercise
etc) from early childhood.

Intervention –Health promotion by individual or

mass health education.
.
Primary prevention

Action taken prior to the onset of disease which

removes the possibility that a disease will ever occur.
eg immunization, specific nutrients to prevent
deficiency diseases.
Intervention --- specific protection.
Primary prevention includes the concept of “Positive
health”.
Positive Health means an acceptable level of health that
will enable every individual to lead a socially and
economically productive life.
• Primary prevention is now being applied to the prevention of chronic
diseases such as coronary heart disease, hypertention and cancer
based on elimination or modification of “risk factors” of disease.

• Primary prevention is a holistic approach, that designed to to promote

health or to protect against specific disease agents and hazards of
environment.

• It utilizes the prepathogenesis phase of disease (agent—host—

environment).
Secondary prevention
Action which haults the progress of a disease at its incipient stage and prevents
complications.eg early diagnosis and treatment.

Intervention –early diagnosis(by screening tests) and adequate treatment.

Secondary prevention attempts to arrest the disease process, restore health, treating it
before irreversible pathological changes.
Tertiary prevention
When the disease process has advanced beyond its early stages,
prevention at that stage is called tertiary prevention. eg. limit sufferings
and dissabilities.

Intervention ---Disability limitation and rehabilitation.

Modes of intervention of Disease
1. Health promotion
2. Specific protection
3. Early diagnosis and treatment
4. Disablity limitation
5. Rehabilitation
Community diagnosis
Community diagnosis may be defined as the
pattern of disease
in a community
described
in terms of
important factors
Which
influence this pattern.
Community treatment
• Community treatment or community health action
is the
sum of steps
decided upon
to meet the health needs
of the community
taking into account
the resources available
and the wishes of the people
as revealed by community diagnosis.
• Isolation:- It is the separation of an infected person for the period of
communicability of the disease, in order to prevent or limit the direct
or indirect transmission to those who are susceptible.

• Quarantine:- It is the restriction of movement of apparently healthy

persons who have been exposed to a communicable disease during
its maximum incubation period.
• Surveillance:- It is the ongoing systemic collection, compilation,
analysis and interpretation of data; and the dissemination of
information to those who need to know in order that action may be
taken.

• Objective:- A clearly stated outcome of an activity which is defined

before the action take place. or
The intended results that we aspect after implementation of an
activity(s) of a programme.
• Monitoring:- It is a continuous process of looking at the way, that the
activities are being implemented to meet the objectives set and
correcting any deviation, during the process of implementation of a
programme.
• Evaluation:-It is the process of measurement of performance based
on established criteria, to ensure that the objectives set have been
attained.
Physical quality of life index (PQLI)
• It consolidates 3 indicators:
Infant mortality rate
Life expentancy at age one
Literacy
It was measured by 0-100 scale, where 0 represents worst performance and
100 for best performance.
Human develpoment index (HDI)
• It consolidates 3 indicators:
• Life expectancy at birth-longivity of life
• Adult literacy rate and mean years of schooling- knowledge
• Real GDP in US Dollar-income
• DETERMINENTS OF HEALTH------

Health is multifactorial .The factors which influence health lie both

within the individual and externally in the society in which he or she
lives.
These factors interact and may lead to health promotion or
deleterious.
Determinants of health
1. Biological determinants e.g, chromosomal
abnormality, metabolic errors, mental retardation.
2. Behavioural and socio cultural conditione.g,
alcohol, smoking.
3. Environmental
4. Socio-economic condition
5. Health services
6. Aging of the population
7. Gender
8. Other factors
Health Indicators
 Indicators of Health:

Definition
By ,Health indicators we can measure the
health status of a community or country ,
and/or compare the health status of country
with that of another.
Indicators of Health: cont.
Uses:
Assessment of health care needs
Allocation of recourses
Monitoring and evaluation of health services, activities and
pogramme
Prioritization of activities
 Types of Health Indicators
1. Mortality Indicators
2. Morbidity Indicators
3. Disability rates
4. Nutritional Status Indicators
5. Health Care Delivery Indicators
6. Utilization Rates
7. Indicators of Social and Mental Health
8. Environmental Indicators
9. Socio-economic Indicators
10. Health Policy Indicators
11. Indicators of Quality of Life
12. Other Indicators.
 Mortality Indicators:-
• Crude Death Rate- number of death per 1000 population per
year in a given community.
• Expectation of life:-Life expectancy at birth-the average
number of years that will be lived by those born alive into
a population if the current age specific mortality rates
persist.
• Infant mortality rate:- It is the ratio of deaths under 1 year of
age in a given year to the total number of live births in the
same year, in a given country or community; usually
expressed as a rate per 1000 live births.
• Maternal Mortality Rate:-It is the ratio of maternal death ie
death of women of reproductive age due to complications
of pregnancy, child birth or within 42 days of delivery from
puerperal causes in an area during a given year divided by
the total number of live births in the same area and year
multiplied by 1000.
Morbidity Indicators-
 Incidence and prevalence rate
 Notification rates
 Attendance rates at OPDs
 Admission, readmission and discharge rates
 Duration of stay in hospital
 Spells of sickness or absence from work or school
Disability rates:
 Event type indicators:
Number of days of restricted activities
Bed disability rates
Work loss days
 Person type indicators:
Limitation of mobility
Limitation of activity
 Sullivan’s index: (expectation of life free of
disability) is computed by subtracting
from the life expectancy
to the probable duration of disability and
inability to perform major activities.

HALE (Health-adjusted life expectancy): the equivalent

number of years
in full health that a new born can expect
to live based on
current rates of ill-health and mortality.
Nutritional status indicators:
Anthropometric measurements of pre school children
Prevalence of low birth weight

Health care delivery indicators:

Doctor population ratio
Doctor Nurse Ratio
Population bed ratio
• Utilization rates:
Proportion of children who are fully immunized
Proportion of pregnant women who receive anti natal
care
Bed occupancy rate
Bed turn over rate
• Indicators of social and mental health:
Number of suicide
Number of homicide
Violence
RTA
Prevalence of Drug abuse
Prevalence of Obesity
☞Socioeconomic indicators:
☞Per capita income
☞Per capita calorie intake
☞Level of unemployment
☞Family size
☞Literacy rate
☞Number of motor car per 1000 population etc.
Health policy indicators:
Proportion of GNP spend for health
Per capita health expenditure

Indicators for quality of life:

PQLI (physical quality of life index): It is the
combination of 3 indices ie IMR, life
expectancy at age 1 and literacy rate.
Other indicators:
Social indicators:
Learning and educational services
Earning facilities
Social security
Old age security
Cultural activities and leisure
Basic need indicators:
Access to safe water
Per capita calorie consumption
Literacy
Doctor population ratio
Room per person
• Iceberg Phenomenon : It is a representative phenomenon by which
natural disease process on human is expressed with an iceberg.

Parts of Iceberg:
1) Flotting tip---- physicians can see.
2)Water line---- demarcation between apparent and inapparent cases
of disease.
3)Submerged portion---large hidden mass of disease e.g, undiagnosed
cases, latent cases, presymptometic cases, inapparent cases, carriers,
reserver .
Epidemiological importance of iceberg of disease:
1. The unknown morbidity of some diseases represent the submerged
portion of iceberg. It exceeds the known morbidity of diseases or
exposed portion of iceberg.
2. The submerged or hidden part of iceberg thus constitutes an
important undiagnosed reservoir of disease or infection in the
community and its control measure is a challenge for preventive
medicine or public health .
Screening :
The search for unrecognized disease or defect by means of rapidly
applied tests, examinations or other procedures in apparently healthy
individuals”.
e.g: Pap smear for cervical cancer.
CXR for TB
• Referral System:
It is a system of two way exchange of information and returning
patients to those who referred to them for follow up care.
Referral system consists of-----
1) Primary health care –at village, community clinic, union and
upazilla level.
2) Secondary health care—District hospital.
3) Tertiary health care—Regional teaching institutes, medical college.
4)Super specialilized care—National specialized institutions,
e,g.BIRDEM, NICVD,NIKDU etc.
• Levels of Health Care Delivery System of Bangladesh:--------

• Disease
• Illness
• Sickness
 Concept of disease
Disease : is a physical or psychological dysfunction.

Illness: is a subjective state of the person who feels

aware of not being well.

Sickness: is a state of social dysfunction assumed by

the patient in response to his illness.
• Epidemiological triad:
## environment:
## agent: any substance living or nonliving or a force tangible or
intangible, the excessive presence or relative lake of which may
initiate or perpetuate a disease process.
## host :
• HOST:
Host is a substance or animal providing lodgement to an infectious agent
under natural conditions.
• Types of host :
1. Obligate host : It means the only host , e.g, man in measles and typhoid
fever.
2. Primary or definitive host : Host in which the parasite attain maturity or
passes its sexual stage .
e.g, female anopheles mosquito for plasmodium species.
Human in Leishmania species.
3. Secondary or intermediate host : Host in which the parasite is in a larval
or asexul stage. e.g, human in plasmodium species. Sand fly in
Leishmania species.
4. Transport host :It is a carrier in which the organism remains alive but
does not undergo development.
5. Accidental host:
• Multifactorial causation of disease :
where disease agent is often not known,
but outcome of interaction multifactors.

Risk Factor:
Where the disease agent not firmly established, the etiology is
generally described as ”Risk factor”.e.g: smoking, obesity, high blood
pressure------causes Heart Disease.
Natural history of disease
• The way in which a disease evolves over time from the earliest stage
of its prepathogenesis phase to its termination as recovery,disability
or death,in the absence of treatment or prevention.
• Prepathogenic phase
• Pathogenic phase
Prepathogenic phase
• Refers to the period preliminary to the onset of disease in man.
• Agent
• Host
• environment
Pathogenic phase
• Begins with the entry of disease agent in susceptible host.
• Agent factor:
biological
nutrient
physical
chemical
mechanical
social
• Host factors
demographic
biological
social and economic
life style
• Environmetal factor
physical
biological
psychological
Spectrum of disease
• Is a graphical representation of variations in the manifestations of
disease.

Subclinical infection >mild>moderate>severe>fatal

illness.
Disease spectrum can be interrupted by preventive measures, early
diagnosis and treatment.
Disease control
Aim/objectives of disease control:

1) To reduce the incidence of disease

2) To reduce the duration and transmission of disease.
3)To reduce the effects of infection.
4)To reduce the financial burden to the community.
• Elimination: Interruption of transmission of disease.
Measles
polio

• Eradication: Termination of all of transmission infection by

extermination of the infectious agent.
• Disease Cycle of Communicable Disease-----

Stage 1---incubation period

Stage 2-----Prodromal period.
Stage3-----Fastigium.
Stage 4----Defervescence
Stage 5----Convalescence
Stage 6-----Defection.