Transcript Third transition

Global Health in the News
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Epidemiologic Transitions: Present and Future
PUBHLTH 350
Matthew L. Boulton, MD, MPH
September 30, 2015
Outline
• Features of the third transition
• Classifying countries by development
status
• Summarizing the transitions
Review: what are the transitions?
• The demographic transition was first conceptualized to
describe changes in country-specific birth rates and
mortality rates over time
• Jacobsen explores changes during the second transition
which occurred with industrialization
• Harper (the reading) also refers to a first transition with
the development of agriculture and a third transition with
the reemergence of infectious diseases
• Transitions are a widely used concept in demography,
medical anthropology, economics, and public health
Harper K, Armelagos G. Int J Environ Res Public Health. 2010;7.
The Three Transitions
Pre-first transition: hunter-gatherer society
Hunter-gatherer societies
First transition
Transition to agrarian societies
Early modern times in the United States
Many modern low-income countries
Second transition
Industrialization
Mid 20th century in the United States
Many modern middle-income countries
Third transition
Into the future: reemergence of infectious diseases
21st century in the United States
Harper K, Armelagos G. Int J Environ Res Public Health. 2010;7.
REVIEW
Post 1st
Pre 2nd transition
2nd transition
Post 2nd transition
High birth rate
High death rate
Stable population
Declining death rate
High birth rate
Increasing population
Reduced birth rate
Reduced death rate
Stable (or decreasing)
population
Nutrition Transition
Pre-first transition: hunter gatherer society
Varied hunter-gatherer diet
First transition
Diet reliant on crops
Second transition
Varied diet, over-nutrition common
Third transition
Varied diet, over-nutrition common
Harper K, Armelagos G. Int J Environ Res Public Health. 2010;7.
Epidemiologic Transition:
Common Causes of Morbidity and Mortality
Before the first transition: pre-agricultural society
Infections: tapeworms, body lice, pinworms, typhoid, staph, yaws
First transition
Infections: malaria, smallpox, measles, tuberculosis
Nutritional deficiencies
Second transition
Chronic diseases: heart disease, diabetes, cancer
Allergies, asthma, autoimmune disease
Sexually transmitted infections: herpes, gonorrhea
Third transition
Diseases in second transition +
Antibiotic resistant forms of tuberculosis, strep, staph, and others
Harper K, Armelagos G. Int J Environ Res Public Health. 2010;7.
The Third Epidemiologic Transition
Characterized by:
1. Detection of new diseases
2. Reemergence of infectious disease
3. Rise of antimicrobial resistance
Barrett. Annu Rev Anthropol. 1998;27.
The Third Epidemiologic Transition:
Detection of New Diseases
• Large number of new pathogens detected
in past 40 years
– Better surveillance
• Legionnaire’s disease discovered in 1976, but now
known to be responsible for previous deaths
– Increased incidence of new pathogens
worldwide:
•
•
•
•
HIV
Viral hemorrhagic fevers (Ebola, Marburg, Hanta)
Lyme disease
West Nile
Barrett. Annu Rev Anthropol. 1998;27.
The Third Epidemiologic Transition:
Reemergence of Infectious Disease
• Climate change
– Warmer climates create favorable environments for the cholera bacteria
• Urbanization + human encroachment on the natural environment
– Dengue fever-carrying mosquitos thrive in slums
– Avian influenza from wild poultry in China
• Other factors
– TB: increased incidence in the US in the early 1990s, and continued high
incidence in Eastern Europe
– Pertussis (whooping cough): rise in the US despite vaccination
– Recent epidemic of measles in France and remainder of Europe
Barrett. Annu Rev Anthropol. 1998;27.
U.S. Spread of WNV Infection, 1999 - 2003
1999 (62)
2000 (21)
2001 (66)
2002 (4,156)
2003 (>9,800)
Human WNV infections
WNV activity
The Third Epidemiologic Transition:
Rise of Antimicrobial Resistance
Globally, antimicrobial resistance
• causes significant mortality
• hampers the control of infectious diseases
• threatens a return to the pre-antibiotic era
• increases the costs of health care
• jeopardizes health-care gains to society
• threatens health security, and damages trade and
economies
Barrett. Annu Rev Anthropol. 1998;27.
http://www.who.int/mediacentre/factsheets/fs194/en/
• In 2013, 9 million cases of TB, 1.3 million deaths
• 480,000 cases of multidrug-resistant tuberculosis (MDR-TB)
• 3.5% of new cases and 20.5% of previously treated cases are
MDR-TB
• Estimated 9% of people with MDR-TB had extremely drug
resistant TB (XDR-TB)
http://www.finddiagnostics.org/export/sites/default/programs/scaling_up/unitaid_expand_tb/
images/MDR-TB_Map_2014.PNG
Classifying Countries Today
• First/second/third world
– Cold War-era political term
– Imprecise
• By development
– developed, developing (least developed)
– definition from the International Monetary Fund (IMF)
• By per capita income
– high income, upper middle income, lower middle income, low
income
– definition from the World Bank
• The “most developed” countries are members of the
Organization for Economic Co-operation and Development
(OECD)
First, Second, and Third World?
Description of Cold War alliances:
• First World (Blue): Capitalist countries
• Second World (Red): Communist
• Third World (Green): Unallied/neutral
Sometimes used as a sliding scale to describe development
 not recommended.
These are not useful terms in scientific or global health discourse.
Countries by Development
• “A developed country is one that allows all its citizens to enjoy
a free and healthy life in a safe environment.” Kofi Annan
• According to the UN development program, human
development index of a country has the following
components:
–
–
–
–
Life expectancy at birth (years)
Mean years of schooling (years)
Expected years of schooling (years)
Gross national income per capita
http://hdr.undp.org/en/content/table-1-human-development-index-and-its-components
Human Development Index World Map
http://www.thenatureofcities.com/TNOC/wpcontent/uploads/2015/01/HumanDevelopmentIndex2014-1059x560.jpg
Income Groups
Based on gross national income per person per annum
• Low-income : $1,035 or less
• Lower middle-income : $1,036 to $4,085
• Upper middle-income : $4,086 to $12,615
• High-income : $12,616 or above
World Bank. 2013. http://data.worldbank.org/about/country-classifications/a-short-history
World Bank Country Income Groups
http://chartsbin.com/view/2438
Figure 2.8: World Population - 1950 to 2050
Adapted from: Haub, Carl and PRB. Data from United Nations Population Division. World
Population Prospects, The 2008 Revision. Available at: http://esa.un.org/UNPP/. Accessed
December 4, 2010. in Skolnik. Global Health 101.
OECD: Organization for Economic
Cooperation and Development
Sometimes referred to as the, “Rich country club”
These countries are often compared to each other in international rankings.
OECD comparison example
Recap: the Three Transitions
When did the
transition occur
in the US?
Pre-agricultural
society
First transition
Second
transition
Third transition
(before European
settlement)
(before European
settlement)
Mid 20th century
Current and
future
Colonial era to
early 20th century
Mid to late 20th
century
21st century
What was the
post-transition
era in the US?
Currently
typical of what
country?
Hunter-gatherer
societies
Low income
countries
Middle income
countries
High income
countries
Demographic
features
Low mortality?
Low fertility
Small population
High mortality
High fertility
Large population
Low mortality
Declining fertility
Large population
Low mortality
Low fertility
Large or declining
population
Nutritional
features
Varied diet
Crops,
undernutrition
Varied diet,
overnutrition
Varied diet +
processed food,
overnutrition
Epidemiologic
features
Infectious diseases
Infectious
diseases
Chronic diseases
Chronic diseases
+ reemerging
infectious
diseases
Epidemiologic Transitions
• Many low and middle income countries exhibit signs of
multiple transitions
– e.g., overweight and underweight being highly prevalent within
one village
– e.g., antibiotic resistance developing even as the prevalence of
infectious diseases decreases
• The third transition is a newly developed concept and the
extent of its applicability is yet to be fully defined
Skolnik. Global Health 101.
http://dl.lshtm.ac.uk/DLTesting/ANH101/sessions/S1S1/images/top_10_causes_of_death.png
Jacobsen. Global Health 2nd Ed.
Jacobsen. Global Health 2nd Ed.
Questions of the Day
How do you think the third epidemiologic transition will play
out globally?
Are developed nations “exporting” the third transition to
developing countries?