Transcript Chapter 4

Chap 4: Epidemiology: Prevention and
Control of Disease and Health Conditions
Instructor: Ping Luo, Ed.D
Fall Semester, 2004
Chap 4: Prevention and Control
Chapter Objectives
• Explain the difference between
communicable and noncommunicable
diseases and between acute and
chronic diseases.
• Describe and explain communicable
and multicausation disease models.
• Explain why noncommunicable
diseases are a community health
concern and provide some examples
of communicable and provide some
examples of important
noncommunicable diseases
Chap 4: Prevention and Control
Chapter Objectives
• Explain how communicable diseases
are transmitted in a community using
the “chain of infection” model and
use a specific communicable disease
to illustrate your explanation.
• Explain the difference between
primary, secondary, and tertiary
prevention of disease.
Chap 4: Prevention and Control
Chapter Objectives
• List and explain the various criteria
that communities might use in order
to prioritize their health problems in
preparation for the allocation of
prevention and control resources
• List and discuss the measures for
preventing and controlling the spread
of communicable diseases in a
community.
Chap 4: Prevention and Control
Chapter Objectives
• List and discuss approaches to noncommunicable disease control in a
community.
• Define and explain the purpose and
importance of health screenings.
• Outline a chronic, noncommunicable
disease control program that
includes primary, secondary, and
tertiary disease prevention
components.
Chap 4: Prevention and Control
Classification of Diseases &
Health Problems
• 4 Classification Schemes
• Organ or Organ System
– i.e., heart disease, kidney disease, respiratory
infection
• Causative Agent
– Biological Agents
– Chemical Agents
– Physical Agents
Chap 4: Prevention and Control
Causative Agents for Diseases &
Injuries
Biological
Agents
Viruses
Rickettsiae
Bacteria
Fungi
Protozoa
Metazoa
Chemical
Agents
Pesticides
Food additives
Pharmacologics
Industrial chemicals
Air pollutants
Cigarette smoke
Physical
Agents
Heat
Light
Radiation
Noise
Vibration
Speeding
objects
Chap 4: Prevention and Control
Classification of Diseases & Health
Problems
Organ or Organ System
– i.e., heart disease, kidney disease, respiratory
infection
Causative Agent
– Biological Agents
– Chemical Agents
– Physical Agents
Communicable vs Non communicable
Acute vs Chronic
–Peak symptoms within 3 months (acute) or
longer than 3 months (chronic)
Chap 4: Prevention and Control
Types of Diseases
Examples
Acute Diseases
Communicable
Common cold, pneumonia,
mumps, measles, pertussis,
typhoid fever, cholera
Noncommunicable
Appendicitis, poisoning, trauma
Chronic Diseases
Communicable
Noncommunicable
Tuberculosis, AIDS, Lyme disease,
syphilis, rheumatic fever
Diabetes, coronary heart disease,
osteoarthritis, cirrhosis of the liver
Chap 4: Prevention and Control
Communicable Disease Model
Model
Chap 4: Prevention and Control
Communicable Disease Model
Agent - the element that
must be present in order
for the diseases to occur.
Chap 4: Prevention and Control
Communicable Disease Model
Host - any susceptible
organism invaded
by an infectious agent
Agent
Chap 4: Prevention and Control
Communicable Disease Model
Host
Agent
Environment - all
other factors that inhibit
or promote disease
transmission.
Chap 4: Prevention and Control
Chain of Infection
A model to conceptualize the transmission of a
communicable disease from its source to a susceptible hose
Chap 4: Prevention and Control
Chain of Infection
Pathogen
• is the disease causing agent
Chap 4: Prevention and Control
Chain of Infection
Pathogen Reservoir
• is the habitat in which an infectious
agent normally lives & grows
• Human: symptomatic or asymptomatic
• Animal: called zoonoses
• Environmental: plants, soil, and water
Chap 4: Prevention and Control
Chain of Infection
Pathogen Reservoir Portal
of exit
- is the path by which an
agent leaves the source host
Chap 4: Prevention and Control
Chain of Infection
Pathogen Reservoir Portal
of exit
Transmission
• how pathogens
are passed
Modes of Transmission
Direct
- Direct contact
- Droplet spread
Indirect
- Airborne
- Vehicleborne
- Vectorborne
Chap 4: Prevention and Control
Chain of Infection
Pathogen Reservoir Portal
of exit
Portal
Transmission of entry
• agent enters
susceptible host
Respiratory
Oral
Skin
Intravenous
Gastrointestinal
Chap 4: Prevention and Control
Chain of Infection
Pathogen Reservoir Portal
of exit
Portal
Transmission of entry
New
Host
• Final link is
a susceptible host
Chap 4: Prevention and Control
Noncommunicable Disease Model
Your genetic
endowment
Chap 4: Prevention and Control
Noncommunicable Disease Model
Your genetic
endowment
Behavioral
choices
Chap 4: Prevention and Control
Noncommunicable Disease Model
Environment
Your genetic
endowment
Behavioral
choices
Air
Pollution
Chap 4: Prevention and Control
Prioritizing Prevention & Control Efforts
• Leading Causes of Death
• Years of Potential Life Lost
• Economic Cost to Society
Chap 4: Prevention and Control
Prioritizing Prevention and
Control Efforts
• Leading Causes of Death
• Years of Potential Life Lost
• Economic Cost to Society
Chap 4: Prevention and Control
Prevention, Intervention, Control, and
Eradication of Diseases
• Prevention
– primary
– secondary
– tertiary
• Intervention
– which is defined as taking of action during an
event
• Control
– general term used in the containment of
disease
• Eradication
– total elimination of the disease
Chap 4: Prevention and Control
Levels of Prevention
• Primary
Prevention
– is the forestalling of the
onset of illness or
injury during the prepathogenesis period
(before the disease
process begins)
• Secondary
Prevention
– is the early diagnosis
and prompt treatment
of diseases before the
disease becomes
advanced and disability
becomes severe
•Tertiary Prevention
–
is to retrain, reeducate, and
rehabilitate the patient who has
already incurred disability
Chap 4: Prevention and Control
Chapter 4
Epidemiology:
Prevention and
Control of Diseases
and Health
Conditions