Population
APHG – Spring 2014
http://www.poodwaddle.com/clocks/worldclock
If we shrank the Earth's population to a village of
100 people, with all of the existing human ratios
remaining the same, there would be:
57 Asians
52 females
21 Europeans
48 males
8 Africans
14 people from the Western Hemisphere
(north and south)
30 Christians
6 U.S. citizens holding
70 Non-Christians
60% of the worlds wealth
70 unable to read
80 living in substandard housing
50 suffering from malnutrition
1 near death
1 near birth
Source: Mercy Housing Midwest, Omaha, NE.
1 with a college education
1 with their own computer
Critical Issues in Population
Geography
• More people are alive today than at any other
time in human history.
• The world’s population increased at a faster
rate during the second half of the 20th century
than ever before.
• Virtually all population growth today occurs in
less developed countries (LDCs)
• https://www.youtube.com/watch?v=9_9
SutNmfFk – Population Heartbeat
Key Population Issues
Key Issues
1. Where is the world's population distributed?
2. Where has the world's population
increased?
3. Why is population increasing at different
rates in different countries?
4. Why might the world face an overpopulation
problem?
Population Distribution
https://www.youtube.com/watch?v=sc4HxPxNrZ0- 7 Billion
Key Issue 1: Where Is the World's Population
Distributed?
 Population concentrations
 Sparsely populated regions
 Population density
The scientific study of population characteristics is demography. At a
global scale,. .. the world's so-called overpopulation problem is not
simply a matter of the total number of people . . . but the relationship
between number of people and available resources. At a local scale,
geographers find that overpopulation is a threat in some regions of the
world but not in others. Regions with the most people are not necessarily
the same as the regions with an unfavorable balance between population
and resources.
Where Is the World’s Population Distributed?
• Population Concentrations
– 2/3 of the world’s inhabitants are clustered in
four regions.
•
•
•
•
East Asia
South Asia
Southeast Asia
Europe
– Site and Situation of Population Clusters
• Low-lying areas with fertile soil and temperate
climate
• Near an ocean or near a river with easy access to
an ocean.
Population Distribution
World Population Distribution
World population is very unevenly distributed across the Earth’s surface
and it can be compared to climate distribution.
World Population Cartogram
This cartogram displays countries by the size of their population
rather than their land area.
(Only countries with 50 million or more people are named.)
Where Is the World’s Population Distributed?
• Sparsely Populated Regions
– Humans avoid clustering in certain physical
environments.
•
•
•
•
Dry Lands
Wet Lands
Cold Lands
High Lands
– Places considered too harsh for occupancy
have diminished over time.
• Places of permanent human settlement are termed
the ecumene.
Expansion of the Ecumene
5000 B.C.–A.D. 1900
The ecumene, or the portion of the Earth with permanent human settlement, has
expanded to cover most of the world’s land area.
World Population Distribution by Region
1800–2050
https://www.youtube.com/watch?v=fTznEIZRkLg
Where Is the World’s Population Distributed?
• Population Density
– Density can be computed in up to three ways for
a place.
1. Arithmetic Density
– Total number of objects in an area
– Computation: Divide the population by the land area
2. Physiological Density
– Number of people supported by a unit area of arable land
– Computation: Divide the population by the arable land area
3. Agricultural Density
– Ratio of the number of farmers to amount of arable land
– Computation: Divide the population of farmers by the arable
land area
Population Density
 Arithmetic Density – the total number of people
divided by the total land area ( This measure is also
called population density.) Arithmetic density enables
geographers to make approximate comparisons of
the number of people trying to live on a given piece of
land in different regions of the world.
 There is no relationship between arithmetic density
and standard of living.
Arithmetic Population Density
Arithmetic population density is the number of people per total land area.
The highest densities are found in parts of Asia and Europe.
Physiological Density
 A more meaningful population measure is by looking
at the number of people per area of a certain type of
land in a region.
 The number of people supported by a unit of arable
land is called the physiological density.
 Comparing physiological and arithmetic densities
helps geographers to understand the capacity if the
land to yield enough food for the needs of people.
Physiological Density
Physiological density is the number of people per arable land area. This is good
measure of the relation between population and agricultural resources in a society.
Agriculture Density
 Two countries can have similar physiological
densities, but they may produce different amounts of
food because of different economic conditions.
Agriculture density is the ratio of the number of
farmers to the amount of arable land.
 The Netherlands has a much higher physiological
density than does India but a lower agriculture
density.
 Agriculture density is directly related to standard of
living
Effect of Migration on
Population Growth
Q&A. How densely populated is the planet?
 1st Western Europe, 433 people per sq. mile
 2nd Caribbean, 417 people per sq. mile
 Least densely settled region is Oceania: 10 people
per sq. mile
 United States is 78 people per sq. mile
Q. Does high density in urbanized areas equal
environmental degradation????
Population Densities, 2003
Region
World
More Developed Countries
Less Developed Countries
Africa
Sub-Saharan Africa
Northern Africa
Western Africa
Eastern Africa
Middle Africa
Southern Africa
North America
Latin America
Central America
Pop./Sq. Mile
122
61
160
74
76
57
108
107
41
49
42
68
150
Source: Population Reference Bureau, 2003 World Population Data
Caribbean
417
South America
52
Asia
312
Western Asia
112
South Central Asia 376
Southeast Asia
313
East Asia
334
Europe
82
Northern Europe 141
Western Europe 433
Eastern Europe 41
Southern Europe 288
Oceania
10
Key Issue 2
Why is Global Population
Increasing?
Why Is Global Population
Increasing?
• Components of Population Growth
– Geographers measure population change in a
country or the world as a whole by using three
measures:
• Crude Birth Rate (CBR) – total number of live birth
in a year for every 1,000 people alive in society.
• Crude Death Rate (CDR) – total number of deaths in
a year for every 1,000 people alive in society.
• Natural Increase Rate (NIR) – percentage by which
a population grows in a year.
– Computation: CBR – CDR = NIR
» Remember NIR is a percentage ( n per 100, while CBR
and CDR are expressed as n per 1,000)
World Population Growth
1950–2010
Total world population increased from 2.5 to 6 billion in this half century. The natural
increase rate peaked in the early 1960s and has declined since, but the number of
people added each year did not peak until 1990.
World Population Growth, 1750–2150
Source: United Nations, World Population Prospects, The 1998 Revision; and estimates by the Population Reference Bureau.
http://www.youtube.com/watch?v=9_9SutNmfFk&feature=BF&list=ULadYPZ59_AUc&index=1
Natural Increase
Q&A: When could world population stop
growing?
First one – half million years: the population
growth rate was about zero
1700s modern era of population growth
began
Between 1850 and 1900, the annual growth
rate reached 0.5 percent
By the mid-1960’s rate surged to 2.0 percent
Dropped to 1.7 percent by the mid-1980s,
and declined to about 1.4 percent by 2000.
Natural Increase Rates
The natural increase rate (NIR) is the percentage growth or decline in the
population of a country per year (not including net migration). Countries in
Africa and Southwest Asia have the highest current rates, while Russia
and some European countries have negative rates.
Crude Birth Rates
The crude birth rate (CBR) is the total number of births in a country per 1,000
population per year. The lowest rates are in Europe, and the highest rates are in
Africa and several Asian countries.
Crude Death Rates
The crude death rate (CDR) is the total number of deaths in a country
per 1,000 population per year. Because wealthy countries are in a late
stage of the demographic transition, they often have a higher CDR than
poorer countries.
Population Growth through Natural Increase,
1775–2000
Total Fertility Rates
The Total fertility rate (TFR) is the number of children an average woman in
a society will have through her childbearing years. The lowest rates are in
Europe, and the highest are in Africa and parts of the Middle East.
Infant Mortality Rates
The infant mortality rate (IMR) is the number of infant deaths per 1,000 live births
per year. The highest infant mortality rates are found in some of the poorest
countries of Africa and Asia.
World Infant Mortality Rates
in Selected Countries, 2000
Source: Carl Haub and Diana Cornelius, 2000
World Population Data Sheet (Washington, DC:
Population Reference Bureau, 2000).
Life Expectancy at birth
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.
Why Is Global Population
Increasing?
• Summary of Spatial Patterns
– Developed Countries
• Lower rates of…
–
–
–
–
Natural increase
Crude birth
Total fertility
Infant mortality
– Developing Countries
• Higher rates of…
–
–
–
–
Natural increase
Crude birth
Total fertility
Infant mortality
Why Is Global Population
Increasing?
• Population Structure
– Fertility and mortality vary not only spatially
but also temporally within a country.
– A special bar graph known as a population
pyramid can visually display a country’s
distinctive population structure.
• X-axis
– Percent male displayed to the left of zero
– Percent female displayed to the right of zero
• Y-axis
– Age cohorts typically grouped in 5-year intervals
– Youngest displayed at bottom and oldest at top
Population Age Structure Diagram
Source: United Nations, World Population Prospects, The 1998 Revision
Rapid Growth
Slow Growth
No Growth
Population Pyramids – Stages
Rapid Growth
Guatemala
Nigeria
Saudi Arabia
4
3
2
Zero Growth
Spain
Austria
Greece
Ages 0-14
Slow Growth
United States
Australia
Canada
Negative Growth
Germany
Bulgaria
Sweden
Ages 15-44
5
Ages 45-85+
Population Pyramids in U.S. Cities
Population pyramids can vary greatly, with different fertility rates (Laredo vs.
Honolulu), or among military bases (Unalaska), college towns
(Lawrence), and retirement communities (Naples).
Why Is Global Population
Increasing?
• Population Structure
– Dependency Ratio
• Defined as the number of people who are too
young or too old to work, compared to the number
of people in their productive years.
– People aged 0 to 14 and over 65 years old are
considered dependents.
– Larger dependency ratios imply greater financial burden
on the working class.
» 85 percent in sub-Saharan Africa, while 47 percent in
Europe.
Why Is Global Population
Increasing?
• Population Structure
– Sex Ratio
• Defined as the number of males per 100 females
in the population
– Developed countries have more females than males,
because they tend to live 7 years longer.
Doubling Time
• Doubling Time of a population (years) :
– 70 / Population Growth Rate (%)
( 70 / 2.0% = 35 years )
– Rule of 70 :determine how long it would
take for a population to double at its
present growth rate.
– divide 70 by the population’s annual
growth rate to determine the years
needed to double the size of the
population.
Human Population Doubling Time
Why has the worlds population
grown at such different rates
throughout history?
3 variables: births, deaths, and migration
Balancing Equation:
A. The difference between births and deaths in a
population produces the natural increase(or decrease)
of a population.
B. Net migration is the difference between the number
of persons entering a geographic area (immigrants)
and those leaving (emigrants)
C. Natural increase usually accounts for the greatest
amount of growth in a population, especially within a
short period of time.
Population increases at
different rates
Key Issue 3: Why is population increasing
at different rates in different countries?
The demographic transition model
Population pyramids
Countries in different stages of
demographic transition
Demographic transition and world
population growth
The Demographic Transition Modal
– It is a model consisting of four stages that
helps to explain the rising and falling of
natural increase over time in a country.
– Historically, no country has ever reverted
back to a previous stage.
• Thus, the model can be thought to have a
beginning, middle, and an end.
Demographic Transition Model:
Development & Population Intersect…
Demographic Transition
Stage 1: Early Stationary Stage (No country is currently here)
 Population growth: slow increase
 Birth rates: high
 Death rates: high
Most of humanity’s several-hundred year occupancy of Earth
was characterized by stage 1. Birth and death rates varied
considerably from one year to the next and from one region to
another, but over the long term they were roughly comparable,
at very high levels.
Between 8000 B.C. and A.D. 1750, Earth’s human population
increased from 5 million to 800 million. The burst of population
growth around 8000 B.C. was caused by the agriculture
revolution. Despite the agriculture revolution, the human
population remained in stage1 of the demographic transition
because food supplies were unpredictable.
Demographic Transition
Stage II: Early Expanding Stage
 Birth rates: high
 Death rates: decreasing
 Population growth: rapid and increasing
After around A.D1750 the world’s population suddenly began to
grow10 times faster than in the past. In stage II, the crude death
rate plummets, while the crude birth rate remains the same as in
stage I. Most African countries are still in a stage II.
With the advent of the Industrial Revolution and the
improvements in technology, population growth rate changed.
Countries in Europe and North America entered stage II of the
demographic transition about 1800, but stage II did not diffuse to
most countries in Africa, Asia, and Latin America until the
1950’s. The late 20th century push of countries into stage II was
caused by the medical revolution.
Percent of Population under 15
About one-third of world population is under 15, but the percentage by
country varies from over 40% in most of Africa and some Asian countries, to
under 20% in much of Europe.
Rapid Growth in Cape Verde
Cape Verde, which entered stage 2 of the demographic transition in
about 1950, is experiencing rapid population growth. Its population
history reflects the impacts of famines and out-migration.
Demographic Transition
Stage III: Late Expanding Stage
 Birth rates: decreasing
 Death rates: leveling off
 Population growth: rapid but slowing
A country moves from a stage II to a stage III when the birth rate
begins to drop sharply. European and North American countries
moved from stage II to a stage III during the first half of the 20th
century. Most countries in Asia and Latin America have moved
to a stage III in recent years.
A society enters a stage III when people decide to have fewer
children. Medical practices introduced in stage II improve the
probability of infant survival, but many years pass before
families react by conceiving fewer babies.
Demographic Transition
Stage III continued……
Economic changes in stage III also induce families to have
fewer offspring. Farmers often consider a large family to be an
asset. In contrast, children living in cities are generally not
economic assets.
About 75% of the world’s population is stranded in stages II and
III.
Q&A: What does improve technology increase?
resource availability
standard of living
health care
?
?
Moderate Growth in Chile
Chile entered stage 2 of the demographic transition in the 1930s, and it
entered stage 3 in the 1960s.
Demographic Transition
Stage IV: Late Stationary Stage
 Birth rates: low
 Death rates: low
 Population growth: low
A country reaches stage IV when the birth rate declines to the
point where it equals the death rate. The condition is called
ZPG. Most European countries have reached stage IV. The
United States has moved slightly below ZPG since 2000. When
families lived on farms, employment and child rearing were
conducted at the same place, but in urban societies parents
leave the home to work.
Changes in lifestyles also encourage smaller families. Several
Eastern European countries, most notably Russia, have
negative natural increase rates, a legacy of Communist rule.
Low Growth in Denmark
Denmark has been in stage 4 of the demographic transition since the
1970s,with little population growth since then. Its population pyramid
shows increasing numbers of elderly and few children.
Demographic Transition in England
England was one of the first countries to experience rapid population
growth in the mid-eighteenth century, when it entered stage 2 of the
demographic transition.
Why Does Population Growth
Vary among Regions?
• Population Futures
– Demographic Transition Possible Stage 5:
Decline
• Characterized by…
– Very low CBR
– Increasing CDR
» More elderly people than young persons
– Negative NIR
– Over time, few young women in child-bearing years
» Contributing to ever falling CBR
• Several European countries already have negative
NIR.
– Russia is most notable hosting a negative NIR for 50 years.
Demographic Transition
 Less developed countries : mortality
revolution after World War II; changes did
not result from economic development
within the countries, but were a result of
international aid.
 The impact of Western technology moves a
population from a stage I into a stage II.
Industrialization and economic development
moves populations into a stage IV
• Declining Birth Rates
– Two Successful Strategies for Lowering Birth
Rates
1. Improving Education and Health Care
– Emphasizes improving local economic conditions so that
increased wealth is allocated to education and health
programs seeking to lower birth rates.
2. Contraception
– More immediate results reaped than previous approach
– Met with greater resistance, because it goes against
cultural or religious beliefs of some.
» Roman Catholics, fundamentalist Protestants,
Muslims, and Hindus.
Future Population Trends
Key Issue 4: Why Might the World Face an Overpopulation
Problem?
 Malthus on overpopulation
 Declining birth rates
 World Health Threats
 Malthus argued that the world’s rate of population
increase was far outrunning the development of food
supplies
 Malthus claimed that population increased geometrically,
while food supply increased arithmetically.
 Malthus concluded that population would press available
resources in every country, unless “moral restraint”
produced lower birth rates or unless diseases, famine,
war, or other disasters produced higher death rates.
Malthus on Over Population
– He claimed the population was growing faster
than the increase in food supply.
– Malthus’s Critics
• Many geographers consider his beliefs too
pessimistic.
– Malthus’s theory based on idea that world’s supply of
resources is fixed rather than expanding.
• Many disagree that population increase is not a
problem.
– Larger populations could stimulate economic growth, and
therefore, production of more food.
Malthus Theory
• Malthus on overpopulation
– An Essay on the Principle of Population
(1798): Population grows geometrically
while food supply grows arithmetically
– Criticism of Malthus includes the following:
• Pessimistic viewpoint
• Failure to consider technological innovation
• Marxist critique
• Malthus on Overpopulation
– Theory and Reality
• Food production has increased over last 50 years
faster than Malthus predicted.
• His model predicted world population to quadruple
over the course of 50 years.
– Not even in India has population growth outpaced food
production.
Food and Population, 1950–2000
Malthus vs. Actual Trends
Malthus predicted population would grow faster than food
production, but food production actually expanded faster than
population in the second half of the twentieth century.
Malthus: Theory & Reality
Projections of World Population
Future of World Population Growth:
Three Scenarios, 2000 to 2100
World population is projected to increase
to 7.8 billion by 2025
8.9 billion by 2050
If the growth rate does not fall and the
worlds population reaches 11 billion by
2100, the population will have doubled in
about 100 years
Components of Population Change
Future of World Population Growth:
Three Scenarios, 2000 to 2100
Patterns of Population Change
Q&A: Why does it take so long to slow or stop population growth?
Population Momentum:
 Growth through natural increase occurs when the birth rate
exceeds the death rate.
 The rate of natural increases of a population depends on birth
and death rates, which are strongly influenced by the population
age.
 The momentum of population growth in less developed countries
will be slowed when the larger number of young adults resulting
from previous high fertility have passed out of the childbearing
years and a smaller generation reproduces at replacement level
fertility.
 Two strategies have been successful in reducing birth rates.
Economic development and distribution of contraceptives.
Impacts of Rapid Population
Growth
Environmental Conditions:
In the past, a relatively small global population with a
low level of technology meant a fairly low impact on
the environment. Today, however, the combination of
a larger global population and high technology has
led to many problems.
 Pollution of air, soil, and water
 Deforestation and desertification
As the global population doubles sometime in the
next 43 years, the pollution level will double – unless
we change the way we extract resources from the
environment.
Resource Availability
 Although increasing our level of technology
enables us to extract more resources from
the environment, we do not know if this
process is infinite: there may be a limit to the
number of resources we can extract from our
planet.
 The availability of resources is largely
determined by access to technology and
resources.
Human Population: Fundamentals of Growth
Environmental Relationships
Per Capita Annual Renewable Freshwater
Availability, 1950, 1995, 2050
Source: Population Action International, Sustaining Water, Erasing Scarcity.
Housing & Hunger
 Countries below “The Line,” population is growing
faster than housing is being built; these countries
cannot afford to build enough housing quickly enough
to keep up with the growing population.
 As this cycle continues, the number of homeless
people will increase.
 At the present time, we can grow enough food to
feed the world. However, people go hungry because
we cannot distribute the food adequately. This
problem has a direct effect on the mental
development of children.
The Brandt Line is a visual depiction of the North-South divide, proposed
by German Chancellor Willy Brandt in the 1980s. It approximately
encircles the world at a latitude of 30° N, passing between North and
Middle America, north of Africa and India, but dipping south so as to
include Australia and New Zealand in the “Rich North.”
The map above showing the north-south divide as been updated recently to
include countries like South Africa, Singapore and Taiwan. It was based upon
the Brandt line and shows the more economically developed countries in blue
and the less economically developed countries in red.
Positives of Map:
Simplifies data so that it's easy to understand.
GDP is used which is an easy to access data source.
Negatives of Map:
Doesn't include some countries which are more economically developed.
Generalized patterns with some countries above the Brandt line less
Medical Care & Education
 Providing sufficient health care is already a
problem in many places; even the United States
cannot provide health care to all its inhabitants. As
the global population grows, this problem will, too.
 Worldwide about 8 million babies die annually
before their first birthday.
 As countries develop economically, infant mortality
usually declines.
 Every year, more and more people are illiterate and every year, more of the illiterate are women.
Status of Women
Although women have gained more
political and economic rights in the United
States, in most of the rest of the world,
women have lost ground
Human Population: Fundamentals of Growth
The Status of Women
Source: Demographic and Health Surveys, 1991–1999
Women's Age at First Marriage (years) and
Family Size (TFR) in Selected Countries,
1990s
Global Security & Wilderness
 Remember, as population grows, the demand for
resources grows. If there is a limit to the amount of
resources, competition for what is available will
increase, which will threaten political and economical
infrastructures.
 The more population grows, the more difficult it is to
maintain wilderness area.
 It is hard to preserve wilderness in poor areas: food
and money!
Patterns of World Urbanization
Q&A: What are the social implications of rapid population
growth in less developed countries?
 Rural, dependent on agriculture and hunting for survival.
 In 1800, only 3% of the world’s population lived in urban
areas.
 1900, almost 14% were urbanites, only 12 cities had 1
million or more people.
 1950’s, 30% of the world’s population resided in urban
centers. 83 cities had over 1 million
 2000, about 47% of the world’s population lived in urban
areas(2.8 Billion)
 411 cities over 1 million
 Developed nations are about 76% urban
 40% of residents of less developed countries live in
urban areas
Future Urbanization Patterns
 2030, 60% of the world’s population will be urban
 Most urban growth will occur in less developed
countries.
Q&A: What is an urban area?
Any place with a population of 2500 + urban; some
set a minimum of 20,000.
 2000, 39% of the world’s urbanites lived in
agglomerations of 1 million
 15% resided in agglomerations of 5 million or
more.
 8% of Americans live in cities of 1 million or more.
Megacities
 10 Million habitants = megacities
 1950: 8cities had populations of 5 million or
more 2 of them in less developed countries
 2000: 41
 2015, 59 megacities will exist, 48 in less
developed countries
 1950, only one city had more than 10 million
people
 2015, 23 cities are projected to hold over 10
million people; all but four will be in less
developed countries.
Largest Urban Agglomerations, 1950, 2000, 2015
Source: United Nations, World Urbanization Prospects, The 1999 Revision
Top 10 Largest Urban Agglomerations
in 1950, 2000, 2015
1950
1. New York, USA 12.3
2. London, England 8.7
3. Tokyo, Japan
6.9
4. Paris, France
5.4
5. Moscow, Russia 5.4
6. Shanghai, China 5.3
7. Essen, Germany 5.3
8. Buenos Aires, Arg 5.0
9. Chicago, USA
4.9
10. Calcutta, India
4.4
2000
1. Tokyo, Japan
26.4
2. Mexico City, Mex. 18.4
3. Bombay, India
18.0
4. Sao Paulo, Brazil 17.8
5. New York, USA 16.6
6. Lagos, Nigeria
13.4
7. Los Angeles
13.1
8. Calcutta, India
12.9
9. Shanghai, China 12.9
10.Buenos Aires, Arg 12.6
2015
1. Tokyo, Japan
26.4
2. Bombay, India 26.1
3. Lagos, Nigeria 23.2
4. Dhaka, Bang.
21.1
5. Sao Paulo, Bra 20.4
6. Karachi, Pakistan 19.2
7. Mex. City, Mex. 19.2
8. New York, USA 17.4
9. Jakarta,Indonesia17.3
10. Calcutta, India 17.3
Source: United Nations, World Urbanization Prospects, The 2005 Revision
http://www.youtube.com/watch?v=sc4HxPxNrZ0
Growth of Urban Agglomerations, 1950–2015
Why Might Overpopulation be a Concern?
https://www.youtube.com/watch?v=jbkSRLYSojo- Hans Rosling “200”
Epidemiologic Transition:
World Health Threats
 Stage 1: Pestilence and famine
Stage of pestilence and famine
Infectious and parasitic diseases were principal
causes of death
Black Plague
Pandemics
 Stage 2: Receding pandemics
Stage of receding pandemics
Occurs over a wide geographic area
Effects a high proportion of the population
Cholera
Cholera in
London, 1854
Stage 2:
Receding
pandemics
Cholera
and
Dr. John
Snow
By mapping the distribution of cholera cases and water pumps in Soho, London,
Dr. John Snow identified the source of the waterborne epidemic.
Epidemiologic Transition
 Stage 3: Degenerative diseases
Degenerative and human created diseases
Decrease in deaths from infectious diseases
and an increase in disorders associated with
aging
Cardiovascular disease and cancer
 Stage 4: Delayed degenerative diseases
Delayed degenerative diseases
Heart diseases and cancer
Life is extended through medical advances
Epidemiologic Transition
 Stage 5: Reemergence of infectious diseases?
 Stage of reemergence of infectious and parasitic diseases
 Evolution of diseases
 Poverty
 Travel
 Malaria
 Tuberculosis
 SARS
 AIDS
– Three reasons why it might be happening:
» Evolution
» Poverty
» Improved travel
HIV/AIDS Prevalence Rates, 2011
The highest HIV infection rates are in sub-Saharan Africa. India and China
have large numbers of cases, but lower infection rates at present.
SARS Infections in China, 2003
China had 85 percent of the world's SARS cases in 2003. Within China, the
infection was highly clustered in Guangdong Province, Hong Kong, and Beijing.
Tuberculosis Death Rates, 2000
The tuberculosis death rate is a good indicator of a country’s ability to invest in
health care. TB is still one of the world’s largest infectious-disease killers.
Why Do Some Regions Face Health
Threats?
• Health Care
– Health conditions vary around the world,
primarily, because countries possess different
resources to care for people who are sick.
• Expenditures on Health Care
– More than 15 percent of total government expenditures in
Europe and North America.
– Less than 5 percent in sub-Saharan Africa and South Asia.
Why Do Some Regions Face Health
Threats?
• Health Care
– Health Care Systems
• Developed Countries
– Public service available at little or no cost.
– Government pays more than 70 percent of health-care
costs in most European countries, and private
individuals pay about 30 percent of the expense.
• Developing Countries
– Private individuals must pay more than half of the cost of
health care.
» U.S. is an exception to these generalizations, because private
individuals are required to pay about 55 percent of health care
costs making it more closely resemble a developing country, in
regards to health care.
Up Next: Migration
Read Chapter 3