Download Lecture 2 Introduction, Part II

Epidemiology
and
Public Health
Introduction, Part II
Changing Patterns of
Community Health
• Health patterns in constant state of flux
• Infectious versus chronic diseases
• Population and age-related
Chain of Infection
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Etiological agent
Source/Reservoir
Portal of exit
Mode of transmission
Portal of entry
Susceptible host
Modes of Transmission
• Contact transmission
• Vehicle transmission
• Vector transmission
Classes of Epidemics
• Common source (vs. sporadic)
Point source
Intermittent
Continuous
Propagated
Your Assignment:
Define these terms
& identify which apply
to the following
three graphs
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
Epidemiology and Clinical
Practice
• Clinical practice dependent on
epidemiology
• Epidemiology defines natural history
of disease
• Even descriptive information is
useful
The Epidemiologic
Approach
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Multistep process
First - determine association
Then prove causation
Not all associations are causal
Examine validity, false assumptionse.g. - fluoride in water
Analytic Studies
• Type of study
• Design
• Analysis of data
Epidemiology and
Prevention
• Identify high risk populations
• Modify risks
• Prevent exposures
Levels of Prevention
• Primary
• Secondary
• Tertiary
Levels of Prevention (cont’d)
• Primary
Involves halting any occurrence of
a disease or disorder before it
happens
Levels of Prevention (cont’d)
• Secondary
Health screening and detection
activities
Levels of Prevention (cont’d)
• Tertiary
Retard or block the progression of
condition