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.

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 Degenerative diseases Share of mortality Low Fertility Low Mortality High Fertility High Mortality LI=70 years LI=30 years LI=50 years Communicative diseases High Fertility Decreasing Mortality Time

The Epidemiologic Transition

The Epidemiologic Transition Stage 1: Pestilence and Famine Infectious and parasitic diseases Epidemics Example Black Plague High CDR

The Epidemiologic Transition Stage 2: Receding Pandemics Improved sanitation, nutrition, & medicine during Industrial Revolution Rapidly Declining CDR

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.

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)

The Epidemiological Transition Stage 3 – Degenerative & human-created diseases Chronic Disorders associated with aging Cardiovascular diseases (hear attacks) & cancer Moderately Declining CDR

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

Sprawl & Obesity

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

Sprawl, Weight and Blood Pressure

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

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.

Avian Flu, 2003 - 2006 Fig. 2-25: The first cases of avian flu in this outbreak were reported in Southeast Asia.

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.

Health Care Indicators of Health Provision of Health Care Infant Mortality rate Life Expectancy Provision of Health Care Health Care expenditures Available Medical Services

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.

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.

Health Care per Capita

Government Expenditures on Health Care