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Morgan N. Schroeder Date Impact of urbanization on the burden of infectious and non-communicable diseases in urban communities in Africa and South Asia By Morgan N. Schroeder Master of Public Health Hubert Department of Global Health _________________________________________
Robert F. Breiman, MD Thesis Advisor Impact of urbanization on the burden of infectious and non-communicable diseases in urban communities in Africa and South Asia By Morgan N. Schroeder Bachelor of Arts in Microbiology and Zoology Ohio Wesleyan University 2010 Thesis Advisor: Robert F. Breiman, MD An
of A thesis submitted to the Faculty of the Rollins School of Public Health of Emory University in partial fulfillment of the requirements for the degree of Master of Public Health in the Hubert Department of Global Health 2014 Abstract Impact of urbanization on the burden of infectious and non-communicable diseases in urban communities in Africa and South Asia By Morgan N. Schroeder Urban growth in the developing world is occurring at an unprecedented rate and magnitude;
consequently many cities are stretched beyond their capacity to provide basic services to their citizens. People are drawn from rural settings to cities seeking opportunities, greater access to resources, and hope for a better future, but realization of these dreams is achieved by very few..
Of the 3.3 billion people living in urban areas worldwide, more than one billion people live in slums, including 56% of South Asians and 70% of sub-Saharan Africans.
The nature of informal settlements exposes the urban poor to a profound number of disease factors for disease, but data are limited on the extent of the problem among urban slum populations, which hinders evidencebased action and interventions. This review examines the current and projected burdens of infectious and non-communicable disease in urban slums attributable to urbanization-related factors such as poor infrastructure, overcrowding, and lifestyle changes in African and South Asian countries, and identifies gaps and limitations of current knowledge about their prevalence and risk factors. Research in the future should include the collection of standardized, disaggregated urban health data to inform evidence-based action, engagement of the community and formation of multi-sectoral partnerships, and the enactment of innovative policies and programs that challenge underlying social norms that perpetuate the existence of urban slums, ultimately transforming the impact of urbanization from negative to positive.
Impact of urbanization on the burden of infectious and non-communicable diseases in urban communities in Africa and South Asia
So many thanks to my terrific advisor, Rob Breiman, for his genuine interest in mentoring me and his patience while helping me to synthesize and refine a complex, fascinating, and utterly enormous topic into something meaningful, useful, and catalyzing. His dedication to urban health and passion for those living in urban slums is truly inspiring, and I consider myself lucky for our paths to have intersected at Rollins. I look forward to a continued friendship throughout my career in public health.
Thank you to my ADAP, Theresa Nash, for assisting me in the search for the perfect thesis advisor and for her genuine friendship and kindness when I needed it most. Thank you to research librarian Barbara Abu-Zeid for her help with narrowing my topic and developing search terms that made this literature review a reasonable undertaking.
Thank you to my family—Jack, Kathleen, Jason, and Courtney; Barb and Dennis; Sandy, Luther and Amelia; and Nannie—for always telling me to shoot for the moon but also for being the scaffolding that has held me together whenever I missed. You are all so dear and special to me, and I have been blessed beyond measure to have each of you a phone call or less away for advice, encouragement, a trip to the tea room, or just to hear that you’re all counting on me.
Finally, I owe my undying gratitude to my tireless and amazing husband Max for everything, everything, everything. What a journey the past 6 years have been together! I could never fully explain how grateful I am to have you as my partner and supporter through it all, but thank you for the sacrifices you have made while I have chased my dreams in microbiology, public health, and beyond. Thank you for supporting me through the long nights of writing, for lending your superb editing and troubleshooting skills, and for helping me to conquer my fears time and time again. I love you!
Table of Contents
Chapter 1: Introduction
1.1 Background and significance
1.2 Statement of the problem
1.3 Statement of purpose
1.4 Research questions
Chapter 2: Methods
Chapter 3: Results
3.1 Burden of infectious diseases in African urban centers
3.2 Burden of non-communicable diseases in African urban centers
3.3 Burden of infectious diseases in South Asian urban centers
3.4 Burden of non-communicable disease in South Asian urban centers.................35 Chapter 4: Discussion, Recommendations & Conclusions
The world’s human population has experienced historic, accelerated growth, particularly during the past fifty years with substantial implications on quality of life and health, and on the future of the planet. In 1800, only 3% of the world’s population (then approximately 1 billion people) lived in urban areas; by the 1900s, the proportion reached 14% and urban growth was seen in virtually every region except Africa (Godfrey and Julien, 2005). Yet in the past 5 years, the world population crossed the 7 billion mark and the proportion of citizens living in urban areas surpassed 50%— the rate of growth in Africa is now twice as high as the global average and its population, is projected to double (principally in urban areas) by 2030 (State of the World Population, 2007). The phenomenon of “urban transition,” is considered by many to be one of the most important issues facing public health in the 21st century (Hidden Cities, 2010).
Urbanization is defined by the United Nations Human Settlements Programme (UNHABITAT) as “the process of transition from a rural to a more urban society” (State of the World Population, 2007). People have repeatedly been drawn from rural settings to cities seeking opportunities, greater access to resources, and hope for a better future, but realization of these dreams is not equally achieved by all. This is especially true in the developing world: of the 3.3 billion people living in urban areas worldwide, more than one billion people live in slums, including between 56% of South Asians and 70% of sub-Saharan Africans. Ninety percent of all slum dwellers reside in developing countries (State of the World Population, 2007; Patel and Burke, 2009; van de Vijver, Akinyi, Oti, Olajide, Agyemang, Aboderin, & Kyobutungi, 2013).
Moving to an urban setting involves new risk factors for disease due to swelling
health statistics can be difficult to find and are rarely collected and disseminated to facilitate timely public health action (Leon, 2008). The objective of this review is to examine what is known about the past and current trajectory of urbanization, to characterize the current and projected burdens of disease attributable to massive rates of urbanization in African and South Asian countries, and to discuss the interventions, policies, and next steps that have and should be implemented to improve the lives of a vulnerable and marginalized population of slum dwellers.
1.1 Background and significance The Industrial Revolution and the “first wave” of urbanization. Between the mid-18th century and 1950, Europe and the United States saw its proportion of urban dwellers swell from 15 million people to 423 million people, increasing from 10% of all citizens to more than 50% (Godfrey and Julien, 2005). The momentous London cholera outbreak of the 1840s that prompted John Snow’s classic epidemiological studies originated from the woes of urbanization and the formation of slum conditions marked by virtually non-existent sanitation. Numerous sources of literature during this time period from memoirs to the works of Charles Dickens describe the unimaginable and often horrifying squalor faced by residents of London (Leon, 2008). Mortality in England in the late 1800s was twice as high in urban areas than in rural areas and outbreaks of diarrheal diseases, typhoid, tuberculosis and pneumonia were exceedingly common (Godfrey and Julien, 2005).
Improved sanitation, clean water, and hygiene practices were the single most effective measures that ultimately contributed to the improvement of health outcomes in London. Social
acceptable housing, steps that were critical to facilitating long-term changes in the social makeup (Godfrey and Julien, 2005).
Urbanization’s “second wave.” Developing countries have experienced rates of urbanization in the last 50 years that resembled growth rates in the first wave seen in Europe and the United States, but more recent and projected rates have been described as unprecedented (Godfrey and Julien, 2005; State of the World Population, 2007). Perhaps one of the greatest challenges faced today is that the influx of rural immigrants into urban centers is occurring in countries already bearing an inequitable share of the global disease burden which have little capacity to handle crises of such great magnitude. Another important factor distinguishing this “second wave” of global urbanization from other periods of urban growth is the absence of simultaneous growth of per capita income that might help to offset the strain of planning and scaling up services (Godfrey and Julien, 2005).
Cities with greater than 1 million people—411 cities—house more than 39% of the global population, yet encompass less than 3% of the total land area. One billion people live in Africa today and 294 million reside in urban areas, but the urban population is expected to double by 2030 with minimal or no increase in the rural population (Godfrey and Julien, 2005;
State of the World’s Population, 2007). By 2025, UN-HABITAT projects substantial percent increases of urban growth in some of Africa’s most populous cities, including Dar es Salaam (over 80%), Nairobi (just under 80%), Kinshasa (70%), and many others, with extremely high proportions of residents in these cities living in slums, (Figure 1) (The Urbanization of Africa, 2010). Certain countries in Africa are projected to have between 90% and 100% of urban residents living in slum conditions (Figure 2). The total Asian population living in urban areas is
greatest proportion of urban residents in Asia living in slums will be found in the South Asia region (58%), followed by 28% of urban residents in East Asia and 28% of urban residents in Southeast Asia (Ooi & Phua, 2007). The greatest proportions of urban slum populations in the world are concentrated in countries in sub-Saharan Africa and Asia, especially South Asia (Figure 2).
Figure 2. Forecasted growth of African cities, 2010-2025.
(The Urbanisation of Africa, 2010)
Epidemiological transition and health. People may choose to migrate from rural to urban areas because of the promise of greater opportunities for employment, education, access to healthcare services, or to be closer to family. Alternatively, they may be forced to move because of unexpected displacement by civil unrest, war, or natural disaster. (Godfrey and Julien, 2005).
Regardless of the driving forces, when the rate of urbanization exceeds the capacity of a government to provide basic resources to its citizens, poverty and disparity is never far behind.
Consequently, the formation of slums, shantytowns, squatter housing, and informal settlements is driven by the often unplanned nature of cities and the inability to adequately accommodate huge numbers of rapidly-arriving immigrants. The plight of urban slum dwellers is characterized by a lack of durable and affordable housing, inadequate access to clean water and improved sanitation, and insecure employment (State of the World Population, 2007). Many people are often crowded into small living spaces within communities that are extremely densely populated.
Because these settlements lack formal legal or political recognition, slum dwellers are unable to vote, are afforded few rights and protections, and are generally ignored and unaccounted for in health service planning (Patel and Burke, 2009).
Crowding, inadequate sanitation infrastructure and lack of clean drinking water increase the likelihood of exposure to many pathogens transmitted by feces and respiratory secretions, including diarrheal diseases such as cholera and typhoid, intestinal parasites, tuberculosis, and influenza among others. Ninety percent of children under the age of 5 with malnutrition live in sub-Saharan Africa and South Asia (Olack et al., 2011).
Concurrent to the increased risk of infectious diseases associated with urbanization are the chronic diseases associated with lifestyle changes that tend to occur in the urban