1. Epidemiology Introduction

2. Changing Patterns of Community Health
Health patterns in constant state of flux
(الانماط الصحية في حالة تغير متواصل)
Infectious versus chronic diseases
(الامراض المعدية مقابل الامراض المزمنة)
Population and age-related
(السكان والعلاقة السنيه)

3. Chain of Infection Etiological agent Source/Reservoir Portal of exit
Mode of transmission
Portal of entry
Susceptible host

5. Modes of Transmission Contact transmission Vehicle transmission
Vector transmission

7. Classes of Epidemics Common source (vs. sporadic:متقطع) Point source
Intermittent
Continuous
Propagated
Your Assignment:
Define these terms
& identify which apply
to the following
three graphs

11. Disease Investigation
Establish diagnosis
Identify specific agent
Describe according to person, place and time
Identify source of agent
Identify mode of transmission
Identify susceptible populations

12. Epidemiology and Clinical Practice
Clinical practice dependent on epidemiology
Epidemiology defines natural history of disease
Even descriptive information is useful

13. The Epidemiologic Approach
Multistep process
- First - determine association
- Then prove causation(اثبات العلاقة السببية)
- Not all associations are causal
- Examine validity, false assumptions-
e.g. - fluoride in water

14. Analytic Studies
Type of study
- Design
- Analysis of data

15. Epidemiology and Prevention
Identify high risk populations
Modify risks
Prevent exposures

16. Levels of Prevention
Primary
Secondary
Tertiary

17. Levels of Prevention (cont’d)
Primary
Involves halting(وقف) any occurrence of a disease or disorder before it happens

18. Levels of Prevention (cont’d)
Secondary
Health screening and detection activities

19. Levels of Prevention (cont’d)
Tertiary
Retard(تأخير) or block the progression of condition

20. Yes may be invo…
Common source – All victims acquire the infection from the same source (e.g. a contaminated water supply).
Continuous source – Common source outbreak where the exposure occurs over multiple incubation periods
Point source – Common source outbreak where the exposure occurs in less than one incubation period
Propagated – Transmission occurs from person to person.