The triple burden: disease in developing nations.

Frenk, Julio ; Gomez-Dantes, Octavio

The world is currently going through one of the most radical health transformations in history. During the past few years, health has ceased being the exclusive concern of domain experts and specialized agencies. Interconnected with national security, economic development, democratic governance, and human rights, it now rightly occupies a central place in the global agenda. We are at the threshold of a new global health era, which poses additional challenges but also offers fresh opportunities.

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The growing recognition of the importance of health has driven an unprecedented expansion in development assistance for health. According to Christopher Murray and colleagues from the Institute for Health Metrics and Evaluation, development assistance increased from US$10.5 billion in 2000 to US$26.8 billion in 2010. It has also led to the creation of new forms of organization; for example, there are now close to 120 multilateral agencies and partnerships active in health.

If we are to meet the challenges and reap the opportunities offered by global health, we need to renew global cooperation, which requires a re-discussion of the complex context of the held, especially in low- and middle-income countries. Most of these countries suffer from a triple burden of disease: the backlog of common infections, undernutrition, and maternal mortality, the emerging challenges of non-communicable diseases (NCDs), such as cancer, diabetes, heart disease, and mental illness, and the problems directly related to globalization, like pandemics and the health consequences of climate change. This triple burden is the central topic of the first part of this article. The second part is devoted to a discussion of the strategies needed to address these challenges. Such strategies include strengthening the local, regional, and global initiatives designed to meet the Millennium Development Goals (MDGs), integrating NCDs into the global health agenda, and transforming the global health architecture to guarantee a rational division of labor among all global health actors. Working in cooperation, we can perform three basic functions: the production of global public goods, the management of externalities across countries, and the mobilization of global solidarity.

Lost in Transition

In the past half-century we witnessed a fundamental transformation in the nature of both death and disease. First, during the 20th century, the world experienced a larger gain in average life expectancy than in all the previously accumulated history of humankind. Life expectancy was only 30 years in 1900. By 1985 it had more than doubled to 62 years. In 2010, according to the United Nations, the average estimate for the world reached 68 years, but with huge regional differences, ranging from 82 years in Japan to scarcely 36 years in Swaziland.

The dramatic increase in life expectancy at birth is only one of a series of demographic changes related to health that are taking place. Because they are not cataclysmic, we tend to lose sight of them. As Joel Cohen points out in a paper on the growth of the human population, during the opening decade of the 21st century there were three firsts in the history of humankind.

In the year 2000, for the first time in history, people aged 60 years and older outnumbered children aged four and younger. In 2007, the urban population outnumbered the rural population, again for the first time ever. In 2003, the average woman in the world started having just enough children during her lifetime to replace herself and the father in the following generation.

From a health perspective, the most fundamental change has been in the dominant patterns of disease. The relative weight of different causes of death has been moving along two dimensions: toward higher age groups and toward chronic conditions.

Thanks to improvements in nutrition, access to water and sanitation, and access to public health interventions such as immunizations and oral rehydration therapy, the burden of disease attributed to undernutrition and common infections has decreased. Major gains in child survival beyond age five have also been made as a result. Populations have begun to live long enough to experience the effects of exposure to health risks related to modern living, such as lack of physical activity, consumption of unhealthy diets and products (tobacco, alcohol, and illicit drugs), stress, and social isolation, which increased the prevalence of NCDs. According to the World Health Organization (WHO), these diseases are now responsible for 60 percent of all deaths worldwide and almost 50 percent of the global burden of disease. The proportion of deaths attributed to NCDs will increase to 75 percent by 2020.

The meaning of illness has also been transformed. Previously, the experience of disease was marked by a succession of acute episodes from which one either recovered or died. Now, people spend substantial parts of their lives in less than perfect health, coping with a chronic condition. Illness may not always kill us, but it always accompanies us. To use Susan Sontag's image, we all now have dual citizenship, both in the kingdom of the healthy and in the kingdom of the sick.

The ongoing health revolution has undoubtedly produced benefits, but it comes with new challenges. Equity is the most daunting of all. Progress on what has been called the health transition has not been shared equally by all nations of the world. Whereas rich countries experienced a clear-cut substitution of old for new patterns of disease, the developing world is facing a complex burden of ill-health.

In its original formulation, developed by Abdel Om-ran, the epidemiologic transition was viewed as a linear movement from communicable to non-communicable diseases. It was just a matter of time: eventually all societies would get rid of the scourge of infection. In 1967, the US Surgeon General made a now famous call to close the book on infectious diseases.

We know better now. We understand that the health transition is not a simple, linear, and unidirectional state, but rather a complex, contradictory, and dynamic process, where several stages may overlap and populations often experience "counter-transitions" with the re-emergence of previously controlled infections.

Maldevelopment: The Fuxtaposition of Challenges

The complexity of these challenges owes not so much to a lack of resources, implicit in the term "underdevelopment," which was used for a long time in reference to poor nations. It probably owes more to what the French sociologist Alain Touraine conceived as "maldevelopment," a biological term referring to an organism that did not develop in the normal wav. In the field of social development, it refers to a mismatch between the needs of a specific population and the responses generated to meet them. Low- and middle-income countries have been victims of maldevelopment because of poor planning procedures, inadequate development models, and badly implemented policies. The essential characteristic of this social process is the juxtaposition of problems. In contrast with currently advanced societies, where new problems have replaced old ones, maldeveloped societies struggle with old and new problems that coexist in a complex context of contradictions and inequalities. The field of health reflects better than any other this unfortunate pattern of development.

First, there is the unfinished agenda of undernutrition, common infections, and reproductive health problems. Recent reports indicate that 850 million people in the developing world still suffer from hunger. Worldwide there are six million preventable child deaths annually, one every five seconds. Most of these deaths could be avoided through measures as simple as basic vaccinations, oral rehydration packages, and micronutrient supplements. Every year, close to 350 thousand women die from complications in pregnancy and childbirth. Most of these deaths could also be averted with timely access to good obstetric care, including emergencies.

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The second component of the triple burden of disease is the emerging challenge of NCDs, which are becoming the main causes of disease and death both in low- and middle-income countries. The most common NCDs are cardiovascular diseases, cancer, and diabetes. Heart diseases are the main cause of death worldwide. They produce 17 million deaths annually, most of which are concentrated in low- and middle-income countries. In fact, cardiovascular diseases are more numerous in India and China today than in the entire developed world. Cancer is another major challenge. The Economist Intelligence Unit estimated at 1 3 million the number of new annual cases of cancer worldwide, half of which occur in poor nations. Furthermore, Goodaerz Danaei and colleagues estimate that the number of adults with diabetes has doubled in the past three decades from 153 million in 1980 to 347 million in 2008. Most of them live in the developing world. The economic impact of this epidemic is enormous: the International Diabetes Federation estimated at US$376 billion the worldwide cost of diabetes in 2010.

The final and third component of the triple burden of disease consists of the health risks associated with globalization. These include pandemics, like AIDS and influenza, the health consequences of climate change, and the dissemination of harmful lifestyles that lead to obesity, which has been called "globesity" precisely to underscore its link with globalization.

Who would have imagined that weight gain would be occupying such a prominent place in the global health agenda at the dawn of the 21st century? In the late i960s there were indications that an overweight problem was developing in the United States. Few people, however, anticipated that this problem would reach epidemic pro-portions, infiltrate western Europe, disseminate to other developed nations, and eventually reach even the world's poorest nations. It has become one of the most overwhelming challenges of our time.

According to a paper by Mariel Finucane and colleagues published in the medical journal The Lancet, there are 1.46 billion overweight adults globally, 495 million of which are obese. Obesity levels range from 3 percent in Japan to around 80 percent in some of the islands of the South Pacific. Children are being increasingly affected. A recent report of the US Institute of Medicine (Early Childhood Obesity Prevention Policies) indicates that 20 percent of American children between the ages of two years old and five years old are overweight or obese. Figures from the latest National Health and Nutrition Survey in Mexico indicate that the prevalence of obesity among children five years old to twelve years old increased from 6 percent to 10 percent between 1999 and 2006. In the developing world this epidemic first affected affluent middle-age adults in urban settings, but it is now spreading to rural areas and indigenous populations and affects younger age groups. Obesity is rapidly becoming a disease of the poor.

The concept that best fits this dynamic picture is the "global transfer of health risks," and at its heart lies what Lincoln Chen and colleagues have called the interdependence of the health of populations. Many health problems spread through processes created to support production, trade, and travel worldwide, and are common to all nations, although with an unequal distribution of both problems and resources to deal with them.

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In the final part of this article, we will address the implications this changing picture holds for the future of the global health agenda and global health organizations.

New Institutional Architecture for Global Health

The challenges related to pre-transitional ailments in developing countries, such as undernutrition, common infections, and reproductive problems, demand the strengthening of all local, regional, and global initiatives designed to meet the MDGs. Most of these initiatives have been directed to the expansion of immunization coverage, increased access to maternal services, and focalized interventions to deal with IIIW.AIDS and malaria, and they are having major impacts. According to the WHO, the expansion of the global coverage of immunizations produced a 74 percent drop in measles deaths between 2000 and 2007. Estimates of the Institute of Health Metrics and Evaluation indicate that annual maternal deaths have fallen from more than half a million in 1980 to less than 350 thousand in 2008. The annual number of new HIV infections and the number of AlDS-related deaths have also diminished because of a significant increase in access to prevention services and anti-retroviral therapy. Finally, the US Centers for Disease Control has stated that the number of global deaths due to malaria declined from almost one million in 2000 to 780 thousand in 2009.

But there are also initiatives that are moving away from vertical or disease-oriented programs and toward stronger health systems as a key strategy to accelerate progress on the health-related MDGs. Health systems with solid infrastructure, a reasonable supply of human resources, and regular access to essential drugs and other inputs can stage interventions focused on high-priority diseases while also providing a wide variety of services.

In order to meet the challenge represented by NCDs, we must first combat the myth that developing countries cannot afford the interventions to address them. There are various successful initiatives that demonstrate that we can mobilize both national and global resources in a fiscally responsible way to expand access to comprehensive services for NCDs. We also need to integrate them with communicable diseases in the global health agenda. One of the main objectives in this regard should be to expand the MDGs to include health targets related to NC-Ds common in low- and middle-income countries, such as hypertension, diabetes, and cervical cancer The High-level Meeting of the UN General Assembly on the Prevention and Control of NCDs in September of this year offers a unique opportunity for the international community to take action against these major threats.

Finally, to deal effectively with the health challenges posed by globalization, we need to mobilize international collective action in a way that engages all actors, since no individual country, no matter how resourceful, can generate on its own an effective response. This, in turn, requires a transformation of the institutional architecture for global health. The basis for such a transformation should be a clear definition of the functions that global health organizations should perform and a rational allocation of these functions to the many institutional actors that today populate the global health space.

International collective action includes three basic sets of functions: the production of global public goods, the management of externalities across countries, and the mobilization of global solidarity.

Four public goods are crucial: research and development, especially regarding problems of global importance; information and databases to stimulate shared learning; common and harmonized health standards for national use; and consensus--building around health policies that can be implemented at local levels. Efforts to manage international externalities include surveillance activities and timely responses to global threats. As the sudden acute respiratory syndrome episode, the H1N1 Influenza pandemic, and the E. coli outbreak have clearly shown, the implementation of these measures requires international and coordinated action. Finally, the mobilization of global solidarity will protect vulnerable populations, such as populations of failed states, victims of human rights violations, and those affected by natural or artificial disasters.

Conventional approaches to aid have tended to focus on the management of externalities and global solidarity. Yet global public goods are crucial tor the design, implementation, and evaluation of policies and programs at the national level. Instruments to manage cross-national externalities are essential to identify and control the international transfer of health risks across borders, from drug-resistant microbes to major outbreaks and pandemics.

The times of clear-cut priorities are gone and global health actors are being increasingly forced to expand the scope of their activities. The initiatives directed to meet the backlog represented by common infections, malnutrition, and reproductive problems are showing positive results but need to be stronger if the health-related MDGs are to be met by 2015, especially among the poorest of the poor. These initiatives also have to be complemented with interventions to deal with NCDs, which are increasingly dominating the health profile of low- and middle-income countries. Finally, several recent experiences have clearly shown that in order to meet the health consequences of an increasingly interdependent world we need to develop a global health system. The basic functions thereof need to be clearly identified, rationally distributed among the several actors of the field, and effectively performed.

In this paper we have argued that global health complexities demand both stronger national health systems and a better coordinated global health system. Their design and implementation require not only a strong technical basis, but also a firm ethical foundation; there is a need not only for ideas but also for ideals. Today more than ever, our globalized world needs a renewed ethic, the ethic of universal rights, so that every human being may have the same opportunity to achieve his or her full potential. The important point here is that social rights, including the right to the protection of health, belong to the category of second-generation human rights, which are, according to Amnesty International's definition, "rights that all people are entitled to regardless of nationality, sex, national or ethnic origin, race, religion, language, or other status." This means that the demand for healthcare can come from anybody, not just from citizens of a particular country. This issue is particularly relevant given the level of migration that the world is witnessing.

The nature of the human right to healthcare also implies that support for this claim can come from anywhere in the world. This opens an enormous field of action tor international advocacy and global solidarity. It is there, in our ability to care for each other, in our determination not to leave anybody behind, in our vision of health as a human right, that we may find the building blocks for a safer and better world.

JULIO FRENK is Dean of the Faculty and Professor of Public Health and International Development at the Harvard School of Public Health. OCTAVIO GOMEZ-DANTES is a researcher at the Center for Health Systems Research, National Institute of Public Health.