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Global Health in the News http://3.bp.blogspot.com/-8DuGQc34kOU/Ve2LCp44fI/AAAAAAAAZ7I/ZGczh55RWZQ/s1600/sierra-leone-ebola.jpg http://www.slate.com/articles/health_and_science/medical_examiner/2015/09/ebola_survivors_symptoms_sierra_leone_who_conference_and_how_to_help.html 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?