Why Do Some Regions Face
Health Threats?
Chapter 2 Key Issue 4
The Epidemiologic Character of Population
Phenomena
■ epi, upon; demos, people; logos, study
■ Epidemiology is the study of what “comes
upon” groups of people.
■ Epidemiology is concerned with the
distribution of disease and death, and with
their determinants and consequences in
population groups.
© Dr. Jean-Paul Rodrigue
1. EPIDEMIOLOGICAL TRANSITION
Concept
 Focuses on changes over time in the causes of mortality
affecting certain populations:
 Health conditions.
 Disease patterns.
 Result in a decline in death rates and an increase of life
expectancy.
 The society goes through a transition from
communicative diseases to degenerative diseases.
1. Epidemiological Transition
Age of communicative
diseases
Age of receding
pandemics
Age of degenerative and
man-made diseases
Share of mortality
Degenerative diseases
Low Fertility
Low Mortality
High Fertility
High Mortality
LI=70 years
LI=30 years
LI=50 years
Communicative diseases
High Fertility
Decreasing Mortality
Time
© Dr. Jean-Paul Rodrigue
The Epidemiologic Transition
© Dr. Jean-Paul Rodrigue
The Epidemiologic Transition
Stage 1: Pestilence and Famine
■ Infectious and parasitic diseases
■ Epidemics
• Example Black Plague
■ High CDR
© Dr. Jean-Paul Rodrigue
The Epidemiologic Transition
Stage 2: Receding Pandemics
■ Improved sanitation, nutrition, & medicine during Industrial
Revolution
■ Rapidly Declining CDR
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue
Cholera in
London, 1854
Fig. 2-23: By mapping the distribution of cholera cases and water pumps in Soho, London,
Dr. John Snow identified the source of the water-borne epidemic.
© Dr. Jean-Paul Rodrigue
Epidemics and Pandemics in Popular Literature
■ Stephen King’s book, The Stand
■ Brad Pitt, Bruce Willis & Madeline Stowe in
the movie “The Twelve Monkeys”
■ Albert Camus’ novel, The Plague
■ Charlton Heston in “Omega Man” & Vincent
Price in “The Last Man on Earth” based on
Richard Matheson’s novel, I Am Legend
■ Edgar Allan Poe’s short story “The Masque of
the Red Death” (also a Vincent Price movie)
© Dr. Jean-Paul Rodrigue
The Epidemiological Transition
Stage 3 – Degenerative & humancreated diseases
■ Chronic Disorders associated with aging
• Cardiovascular diseases (hear attacks) & cancer
■ Moderately Declining CDR
© Dr. Jean-Paul Rodrigue
The Epidemological Transition
Stage 4: Delayed degenerative
diseases
■ Cardiovascular diseases and cancers
■ BUT life expectancy of older people extended through
medical advances
• Cancer growth retarded or removed
• Bypass to repair cardiovascular system
■ High Obesity rates
• Non-nutritious food/sedentary lifestyle
■ Low but increasing CDR
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue
Sprawl & Obesity
© Dr. Jean-Paul Rodrigue
Sprawl and Health Concerns
■ Because this study is ecologic and cross-sectional in
nature, it is premature to imply that sprawl causes
obesity, hypertension, or any other health condition.
■ Our study simply indicates that sprawl is associated with
certain outcomes.
■ Future research using quasi-experimental designs is
needed to tackle the more difficult job of testing for
causality.
“Relationship Between Urban Sprawl and Physical Activity, Obesity, and Morbidity” by Reid Ewing, Tom Schmid, Richard
Killingsworth, Amy Zlot, Stephen Raudenbush in the American Journal of Health Promotion, Inc., September/October 2003,
Vol. 18, No. 1
© Dr. Jean-Paul Rodrigue
Sprawl, Weight and Blood Pressure
© Dr. Jean-Paul Rodrigue
The Epidemiological Transition
Stage 5 – Reemergence of infectious &
parasitic diseases
■ Evolution
• Antibiotics and genetic engineering
• Emergence of new strains of viruses and bacteria
■ Poverty
• Unsanitary conditions in developing countries
■ Increased Connections
• Spreads from Developing to developed countries
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue
Global Warming & Disease
Spread
■ It is possible that if global
warming occurs, the
occurrence and range of
infectious disease might
shift significantly.
■ Areas previously not
prone to widespread
outbreaks of malaria,
might experience a
significant increase in its
incidence.
© Dr. Jean-Paul Rodrigue
Avian Flu, 2003 - 2006
Fig. 2-25: The first cases of avian flu in this outbreak were reported in Southeast Asia.
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue
HIV/AIDS Prevalence Rates, 2005
Fig.
The highest HIV infection rates are in sub-Saharan Africa. India and China
have large numbers of cases, but lower infection rates at present.
© Dr. Jean-Paul Rodrigue
Health Care
■ Indicators of Health
• Infant Mortality rate
• Life Expectancy
■ Provision of Health Care
• Health Care expenditures
• Available Medical Services
© Dr. Jean-Paul Rodrigue
Infant
Mortality
Rates
Fig. 2-10: The
infant mortality rate is the number of infant deaths per 1000 live births per
year. The highest infant mortality rates are found in some of the poorest
countries of Africa and Asia.
© Dr. Jean-Paul Rodrigue
Life Expectancy
at birth
Fig. 2-11: Life expectancy at birth is the average number of years a newborn infant can
expect to live. The highest life expectancies are generally in the wealthiest
countries, and the lowest in the poorest countries.
© Dr. Jean-Paul Rodrigue
Health Care per Capita
© Dr. Jean-Paul Rodrigue
Government Expenditures on Health Care
© Dr. Jean-Paul Rodrigue
© Dr. Jean-Paul Rodrigue