Epidemiology is the study of disease patterns in populations and the application of this study to disease control. This course will introduce students to epidemiology, covering its history, importance, and role in public health. The key topics will include the definition of epidemiology, its goals and differences from infectious disease study, and its contributions to disease control and eradication, as seen in the global eradication of smallpox through vaccination programs and surveillance led by the World Health Organization.

1. Arrowad university
Dr: Haroon Al Yousofy

3. EVALUATION
 Two tests (in classroom)
Midterm (20% )
Final exam (50%)
 Class participation (10%)
 Assignment exercises( 20%) at back of
chapters.assigned exercises but be prepared to
go over exercises at back of chapters in class

4. Course modules
module 1: Introduction to epidemiology.
Goal:
Introduce epidemiology to students
Explain the history and importance of epidemiology
Discuss the differences between epidemiology and infectious diseases
Identify the goals of epidemiology

5. Topic 1

6. Public Health Core Sciences

7. Definition of Health
World health organization (WHO) defined
health: «as a state of complete physical,
mental, social and spiritual well-being
and not merely the absence of disease
or infirmity.»

8. it means perfect functioning
of the body. All the organs of
the body are of average size
and function normally; all
the special senses are intact;
the resting pulse rate, BP and
exercise tolerance are all
within the range of normality
for the individual’s age and
sex.
it is defined as the state of
balance between the
individual and the
surrounding world, a state of
harmony between oneself and
others.
social well-being implies harmony
and integration within the
individual, between each
individual and other members of
the society and between
individuals and the world in
which they live.
1. Physical
dimension
3.
Socioeconomi
c dimension:
2. Mental
dimension:
Dimensions
of Health
4. Spiritual
dimension
: it includes principles and ethics,
the purpose in life, religious
beliefs and values; all are
important components of the
way the person behaves in health
and illness.
5. Other
dimensions
such as: vocational,
environmental, educational,
nutritional, emotional,
political, etc.

9. Determinants of Health

10. Public health is defined as : «
the sciences and art of preventing
diseases, promotion of health
and pro-longing of live

11. TOOLS OF PUBLIC HEALTH
1. Epidemiology
2. Biostatistics
3. Social Sciences
4. Principles of
administration
5. Preventing
Diseases

12. Definition:
The term epidemiology is derived from three Greek
roots (epi = upon, demos = people and ology =
study)
Epidemiology is a branch of public health which
attempts to discover the causes of disease in order to
make disease prevention possible
What is Epidemiology?

13. Epidemiology has been defined as (Last, 1988):
"the study of the distribution and
determinants of health-related
states or events in specified
populations, and the application of
this study to control of health
problems"

14. Key Aspects of This Definition
includes: surveillance, observation, hypothesis
testing, analytic research and experiments.
refers to analysis of: times, persons, places and
classes of people affected.
include factors that influence health: biological,
chemical, physical, social, cultural, economic,
genetic and behavioral.
refer to: diseases, causes of death, behaviors such
as use of tobacco, positive health states, reactions
to preventive regimes and provision and use of
health services.
include those with identifiable
characteristics, such as occupational groups.
the aims of public health—to promote,
protect, and restore health.
Study …………………………….
Distribution ……………….
Determinants …………….
Health-related states and
Specified populations …
Application to prevention
and control
Term Explanation

15. Epidemiology: A Brief History of Development
 Epidemiology is the study of the frequency, distribution, and risk factors for
diseases in populations. It has been a developing science since ancient times,
when people began to observe that some diseases were more common in
certain places than others.
 One of the earliest epidemiologists was the Greek physician Hippocrates (460-
370 BC). Hippocrates described many infectious diseases and proposed some
preventive measures, such as personal hygiene and social distancing.
 In the 16th century, the Italian physician Girolamo Fracastoro (1483-1553)
developed the concept of contagion, proposing that infectious diseases are
spread by small, invisible particles that pass from an infected person to a healthy
person.
 In the 18th century, the English physician John Snow (1813-1858) conducted the
first modern epidemiological study. Snow tracked the outbreak of a cholera
epidemic in London and found that the source of the epidemic was contaminated
drinking water. This study led to the implementation of public sanitation in
London, which resulted in a significant decrease in cholera cases.
 In the 19th century, epidemiology saw a major development, with the discovery
of many infectious disease agents, such as bacteria and viruses. This led to the
development of vaccines and drugs for infectious diseases, which contributed
significantly to improved public health.

16.  In the 20th century, epidemiology continued to develop, with the
development of new methods for studying diseases, such as biostatistics
and data analysis. This contributed to the development of new methods
for preventing diseases, such as vaccination programs and disease
surveillance.
 Today, epidemiology is a fundamental science in public health.
Epidemiologists use their knowledge of epidemiology to study and
prevent diseases in populations.
Some of the most notable recent developments in
epidemiology include:
 Development of new methods for diagnosing diseases, such as DNA
testing.
 Use of modern technology in disease surveillance, such as data analysis
and geographic information systems.
 Participation in efforts to respond to public health emergencies, such as
outbreaks of infectious diseases and epidemics.
 Overall, epidemiology is a vital science in public health, and it has played
a key role in improving human health around the world

17. Importance of epidemiology:
 1. Estimate the prevalence (number of cases) of a
disease.
 2. Describe the pattern of disease
(who is affected)
( where )
(and when).
 3. Identify causation of the diseases; causative
agent(s) and factors behind occurrence and
conditions favor spread of the disease.
 4. Identify modes (ways) of spread (transmission).
• 5. Prevention and control of the disease.

18. Epidemiology is a fundamental science in preventive medicine, which aims to improve the
health of the community by focusing on the causes of diseases and identifying ways to
prevent them. Epidemiology has made significant contributions to disease control around
the world, including the following:
 Development and improvement of vaccines and drugs for infectious diseases.** Epidemiology has been
a major factor in the development and improvement of vaccines and drugs for infectious diseases, such as the
smallpox vaccine, which led to the eradication of smallpox worldwide, and the polio vaccine, which has led to
a significant reduction in cases of polio.
 Improvement of public hygiene and sanitation.
Epidemiology has also contributed to the improvement of public hygiene and sanitation, which has helped to
reduce the spread of infectious diseases. For example, efforts to improve public hygiene and sanitation have
led to the eradication of malaria from many countries.
 Development of public health programs.** Epidemiology is used to develop public health programs that
help to improve community health. For example, vaccination programs help to protect people from
infectious diseases, and disease surveillance programs help to quickly detect new infectious diseases.
 Development of new methods for diagnosing diseases.** Epidemiologists have developed new methods
for diagnosing diseases, such as DNA testing, which has helped to detect diseases more quickly and accurately.
 Use of modern technology in disease surveillance.** Epidemiologists use modern technology, such as
data analysis and geographic information systems, to monitor diseases more effectively.
 Participation in efforts to respond to public health emergencies.** Epidemiologists participate in efforts
to respond to public health emergencies, such as outbreaks of infectious diseases and epidemics.
In general, epidemiology is a fundamental science in preventive medicine, and it has played an important role
in improving human health around the world..
Contributions of Epidemiology to Disease Control

19. Examples for epidemiology role in eradication of smallpox
from the world
 Before the eradication program, smallpox was one of the most common and deadly
diseases in the world. It is estimated that smallpox killed 300 million people in the 20th
century alone.
 The smallpox vaccine was developed in 1796, but it was not widely available until the 20th
century. The first successful smallpox eradication program was launched in 1958 by the
World Health Organization (WHO).
 The WHO smallpox eradication program was a global effort that involved over 100
countries. The program used a combination of vaccination, surveillance, and isolation to
eliminate smallpox from the world.
 The last naturally occurring case of smallpox was in 1977. The WHO declared smallpox
eradicated in 1980.
 These statistics show that epidemiology played a key role in the eradication of smallpox.
By understanding how the disease spread and developing an effective vaccine,
epidemiologists were able to design and implement a successful eradication program. The
eradication of smallpox is a testament to the power of epidemiology and the importance of
global cooperation in public health.
 Here are some other specific statistics that support the role of epidemiology in the
eradication of smallpox:
 In 1967, there were over 10 million cases of smallpox reported worldwide. By 1977, the
number of cases had been reduced to 2,000.
 The last naturally occurring case of smallpox was in Somalia in 1977.
 The WHO declared smallpox eradicated in 1980.