The double burden of communicable and non-communicable diseases in developing countries

Now, at the dawn of the third millennium, non-communicable diseases are sweeping the entire globe. There is an increasing trend in developing countries, where the demographic and socio-economic transition imposes more constraints on dealing with the double burden of infectious and non-infectious diseases in a poor environment, characterized by ill-health systems. It is predicted that, by 2020, non-communicable diseases will cause seven out of every ten deaths in developing countries. Among non-communicable diseases, special attention is devoted to cardiovascular disease, diabetes, cancer and chronic pulmonary disease. The burden of these conditions affects countries worldwide but with a growing trend in developing countries. Preventative strategies must take into account the growing trend of risk factors correlated to these diseases. In parallel, despite the success of vaccination programmes for polio and some childhood diseases, other diseases like AIDS, tuberculosis, malaria and dengue are still out of control in many regions of the globe. This paper is a brief review of recent literature dealing with communicable and non-communicable diseases in developing countries. It gives a global view of the main diseases and their impact on populations living in low- and middle-income nations.     

Epidemiological and nutrition transition in developing countries: impact on human health and development

Whereas common infectious and parasitic diseases such as malaria and the HIV/AIDS pandemic remain major unresolved health problems in many developing countries, emerging non-communicable diseases relating to diet and lifestyle have been increasing over the last two decades, thus creating a double burden of disease and impacting negatively on already over-stretched health services in these countries. Prevalence rates for type 2 diabetes mellitus and CVD in sub-Saharan Africa have seen a 10-fold increase in the last 20 years. In the Arab Gulf current prevalence rates are between 25 and 35% for the adult population, whilst evidence of the metabolic syndrome is emerging in children and adolescents. The present review focuses on the concept of the epidemiological and nutritional transition. It looks at historical trends in socio-economic status and lifestyle and trends in nutrition-related non-communicable diseases over the last two decades, particularly in developing countries with rising income levels, as well as the other extreme of poverty, chronic hunger and coping strategies and metabolic adaptations in fetal life that predispose to non-communicable disease risk in later life. The role of preventable environmental risk factors for obesity and the metabolic syndrome in developing countries is emphasized and also these challenges are related to meeting the millennium development goals. The possible implications of these changing trends for human and economic development in poorly-resourced healthcare settings and the implications for nutrition training are also discussed.     

Introduction. Symposium: Obesity in developing countries: biological and ecological factors

Over the past decade there has been an increasing concern about the impact of chronic, noncommunicable diseases on the health of developing world populations. Traditionally, major causes of illness and death in developing countries have been linked to infectious diseases and undernutrition, and these are still major public health problems in several regions of the world. But recent projections indicate that in 20 y noncommunicable diseases will account for over 60% of the disease burden and mortality in the developing world. Obesity is recognized as an underlying risk factor for many of these chronic conditions. As in developed societies, the risk for obesity in developing countries is also strongly influenced by diet and lifestyle, which are changing dramatically as a result of the economic and nutrition transition. This symposium discusses key aspects of the phenomenon of obesity in the developing world and provides some specific examples from countries facing increasing prevalence of that condition.     

Research capacity strengthening in the South

Active promotion of evidence-based decision-making at all levels of the health field is a necessary step in the direction of improving the health of the population. Recent studies have shown that the burden of disease in developing countries is high particularly the burden of infectious, communicable and non-communicable diseases and health problems of mothers and children. There is presently, a mismatch between this increased disease and health burden and the technical and human capacity of developing countries to use existing knowledge and to generate new knowledge to combat these diseases and health problems. It is therefore necessary to assist developing countries to build indigenous research capability so they can undertake studies in their own national settings the results of which will lead to the development of appropriate control strategies in their countries. Building indigenous research capacity will enable developing country scientists to translate results of studies carried out elsewhere into their individual national settings. Eventually results of such studies will increase the global knowledge base about the particular health problems and contribute to finding appropriate solutions to them. The research will, finally, increase knowledge-based decision-making by their health leadership of the country. This paper has set out to describe some experiences in capacity strengthening over the last few decades and to propose from these, mechanisms for building these capacities in a sustainable manner. This paper has described the steps in capability strengthening with special emphasis on identification of trainees, their training and deployment on return. The paper has described mechanisms of research sustainability including creation of suitable career structures, remuneration of researchers and the importance of building up suitable infrastructure for research to meet increasing demands and competence. The place of partnerships South-South, South-North and networking has been stressed. Finally, the paper calls for greater involvement by policy makers in developing countries in the entire capacity building process. They should set highly focussed research priorities, identify competence not already existing and proceed to fill these gaps along the lines described.     

Nutritional transition and non-communicable diet-related chronic diseases in developing countries

It is increasingly recognized that developing countries are undergoing an epidemiologic transition similar to that which occurred in industrialized countries in previous centuries. While infectious diseases are still the main cause of morbidity and mortality, there is a marked increase in chronic non-communicable diseases, particularly in the most advanced developing countries, and these diseases are expected to take the lead in a decade or two. Most of these diseases, above all coronary heart diseases, stroke and diabetes, are related to diet and lifestyles, for example tobacco and alcohol consumption. As a matter of fact, these societies are also facing a growing epidemic of overweight and obesity, due to the frequent energetic imbalance between energy-dense food consumption and reduced daily physical expenditure. This health transition, favoured by demographic changes towards aging populations, is occurring at an increased pace in urban societies widely exposed to the modernization of lifestyle, sedentary occupation, and to lipid- and sugar-rich food, often poor in fibre and micronutrients. Increased world access to cheaper vegetable oil is thought to have triggered off this accelerated and generalized trend, though animal food, rich in saturated fat, and imported or locally-made industrialized food also play a role. While increased national and household incomes facilitate the initial change, as the transition advances poor people progressively become the main victims, as has been observed in the more advanced developing countries. Metabolic imprinting due to intra-uterine and infant malnutrition, which are still common in these societies, is also thought to play a significant role in the increase in the expression of insulin resistance, obesity and chronic diseases when these children are exposed to abundant food and modern lifestyle, later in life. Treatment and secondary prevention of nutrition-related chronic diseases and associated disabilities have an ever rising cost in industrialized countries, which is far beyond the means of the still fragile economies of developing countries. This double burden of infectious diseases and undernutrition that still exist, and of non-communicable diseases and overnutrition represents a threat to the frequently unprepared health care services in developing countries. There is a clear need to focus health policies on the prevention of chronic diseases through primary health care services, the use of mass media for communication and education about healthy nutrition and lifestyle, and the adaptation of public policies. Nutritionists must also adapt to this changing nutritional situation which may result in apparently contradictory nutritional status findings within societies if not even within households.     

Public health requirements for rapid progress in global health

Abstract

Effective public health interventions can save hundreds of millions of lives in developing countries, as well as create broad social and economic benefits. Unfortunately, public health approaches and solutions applied in developed countries are often assumed to be inappropriate or unattainable in developing countries. This has sometimes forestalled effective interventions in parts of the world where they are most needed, despite conditions that now facilitate lasting solutions to both long-standing and emerging global public health problems. Core public health functions are similar regardless of a country's income level. Although some resource-intensive approaches from industrialised nations are inappropriate in less developed countries, many basic public health measures achieved decades ago in developed countries are urgently needed, highly appropriate, extremely cost-effective and eminently attainable in developing countries today. About half of the disease burden in low and middle-income countries is now from non-communicable diseases, but non-communicable disease epidemics that will otherwise increase rapidly in the developing world can be avoided or reversed. Progress of public health in developing countries is possible, but will require sufficient funding and human resources; improved physical plant and information systems; effective programme implementation and regulatory capacity; and, most importantly, political will at the highest levels of government.     

An overview of cardiovascular risk factor burden in sub-Saharan African countries: a socio-cultural perspective

Background  

Sub-Saharan African (SSA) countries are currently experiencing one of the most rapid epidemiological transitions characterized by increasing urbanization and changing lifestyle factors. This has resulted in an increase in the incidence of non-communicable diseases, especially cardiovascular disease (CVD). This double burden of communicable and chronic non-communicable diseases has long-term public health impact as it undermines healthcare systems.     

The global impact of noncommunicable diseases: estimates and projections

With the aging of populations in developing countries there is both a demographic and an epidemiological transition which affects the impact of chronic degenerative diseases on the health status of the populations. Demographic transition takes place in countries where there are effective programmes of disease control which allow for survival during the early years of childhood and adolescence. This results in an increase in life expectancy which places larger proportions of the population in the age range (60 years and older) in which chronic degenerative diseases become the major determinants of health status. Epidemiological transition in diseases may also be brought about by shifts in social and economic patterns which favour detrimental changes in risk factors for the chronic degenerative diseases. Such changes may include health-related behaviour which augments dietary consumption of fats and alcohol, increases obesity, increases smoking and decreases physical activity. Such changes in risk-factor levels increase the prevalence of chronic degenerative diseases which manifest themselves at later ages, and for which early preventive actions could be cost-effective. In order to illustrate the impact of both demographic and risk-factor effects, analyses are made of the impact of increases in life expectancy on cause-specific mortality in both developing and developed countries. It is shown that there is great similarity in the effect of major noncommunicable diseases on the life expectancy of adults in both developed and developing countries. The major differences are seen to be in the proportions of deaths expected from such diseases as cancer, diabetes, heart disease, stroke and cirrhosis; but not in the distribution of age at death which is the better measure of disease impact. Demographic analyses, computing indirect estimates of mortality, also demonstrate that there are currently more chronic disease deaths in developing than developed countries and that as expectation of life increases in developing countries the global chronic disease burden will be greatly concentrated in the developing countries. Analyses of risk-factor reduction by feasible intervention strategies, e.g. smoking cessation campaigns, treatment of high blood pressure, using relationships between risk factors and diseases established in longitudinal studies carried out in developed countries, point out that the effect of risk-factor control in long-living populations can be hidden by the dependency of risk factors and various related causes of death, e.g. smoking has an impact on lung cancer, ischaemic heart disease and emphysema, but at different ages.(ABSTRACT TRUNCATED AT 400 WORDS)     

World Health Organization global oral health strategies for oral health promotion and disease prevention in the twenty-first century

Despite great improvements in oral health in the past decades, oral disease remains a major public health problem worldwide. The burden of oral disease is particularly high among the disadvantaged population groups in both developing and developed countries. The pattern of oral disease reflects distinct risk profiles across countries that are related to living conditions, lifestyles, environmental factors, and the availability and accessibility of oral health services. In several developing countries, people at large do not benefit from preventive oral health programmes. It is expected that the incidence of dental caries will increase in the near future in many of these countries as a result of growing consumption of sugars and inadequate exposure to fluorides. With the rising use of tobacco in developing countries, the risk of periodontal disease, tooth loss and oral cancer may therefore increase. Several oral diseases are linked to non-communicable chronic diseases or conditions that share common risk factors, such as diabetes, obesity and cancer. Similarly, general diseases often have oral manifestations (e.g. diabetes or HIV/AIDS). Worldwide strengthening of public health programmes through implementation of effective oral disease prevention measures and health promotion is urgently needed, and use of common risk factors approaches should integrate oral health within national health programmes. The challenges to oral health improvement are particularly high in developing countries. The World Health Organization Global Oral Health Programme formulates policies and actions for the improvement of oral health, strategies that are fully integrated with chronic disease prevention and general health promotion. At the 60th World Health Assembly in 2007, the WHO Member States agreed on an action plan for oral health and integrated disease prevention, thereby confirming the approach of the Oral Health Programme. The policy forms the basis for future development of oral health programmes.     

As children survive: dilemmas of aging in the developing world

The decline in infant mortality now occurring in the developing world assures a growing population of older persons with a chronic disease morbidity burden that is predictable and costly. The health needs and related social requirements of the elderly are not always well met even in countries where resources are substantial. In the developing world, this morbidity burden can quickly overwhelm fragile and often underfinanced health infrastructures already unable to meet fully the prevention and treatment needs of a younger population with relatively low-cost, easy-to-prevent, easy-to-treat illnesses. Inappropriate application of costly technology could easily result, accompanied by diversion of resources from existing primary-care services, and paradoxically poor service to the emerging aging population. This paper examines the dilemma, and spells out the issues by examining several chronic diseases in detail. We conclude with suggestions for a policy-oriented research agenda aimed at the development of affordable and humane approaches to the health needs of aging populations, and the prevention and care of chronic diseases in the developing world.     

A global framework for action to improve the primary care response to chronic non-communicable diseases: a solution to a neglected problem

Background  

Although in developing countries the burden of morbidity and mortality due to infectious diseases has often overshadowed that due to chronic non-communicable diseases (NCDs), there is evidence now of a shift of attention to NCDs.     

Advancing Surveillance of Chronic and Non-Communicable Disease—A Path Forward

Objective

To characterize current and future approaches to surveillance of chronic and non-communicable diseases and establish the agenda for both methodological and condition-specific progress.

Introduction

Major global stakeholder groups including the United Nations, World Health Organization and Institute of Medicine seek to raise awareness of the threat to global health and security of chronic and non-communicable diseases. These conditions comprise 50–85% of the global annual morbidity burden and constitute a major drain on national economies. To move from awareness of this problem to action and amelioration of issues, we need effective means for monitoring and intervening with populations using approaches that span primary, secondary and tertiary prevention.

Methods

This session will begin with a discussion of key concepts and terms and their implications for defining target problems, populations and surveillance strategies. We will also begin by reviewing the epidemiologic and economic arguments for advancing surveillance in this area. The discussion will center on a critical assessment of issues related to surveillance of chronic and non-communicable diseases: how do approaches differ from established and evolving approaches to surveillance of infectious disease? Are there opportunities for synergy with current surveillance efforts and assets? Where are new methods needed? How might surveillance approaches be advanced in different regions (e.g., developing and industrialized settings)? Might new approaches predicated on “citizen science” and engaged patient and public health cohorts provide platforms for advancing surveillance of chronic and non-communicable diseases and what is required to ensure their success?

Results

Points of discussion:

1. Participants are encouraged to come prepared to share their experiences engaging patient and public health cohorts in this area, including sharing experiences engaging cohorts using online social networks, participatory research and surveys.
2. Brainstorm ideas for development of a workshop in non-communicable disease surveillance.

Sample questions:

1. What are the issues related to surveillance in the context of resource rich and poor contexts?
2. What are the special needs for establishing cost-effective and sustainable methods for longitudinal tracking?
3. How can technological advances and engaged patient and public health cohorts be used in the advancement of surveillance? What are methods to maximize engagement in both the developed and developing world?

Conclusions

Non-communicable diseases are a major and growing morbidity and mortality burden globally. This round table discussion will focus on the importance of non-communicable disease surveillance, attempt to elicit participant’s experiences in the surveillance of these conditions, and outline special needs for establishing cost-effective and sustainable methods for longitudinal tracking of non-communicable diseases.     

中国慢性非传染性疾病经济负担研究

目的了解中国慢性非传染性疾病经济负担及其变化趋势。方法依据1993年、2003年国家卫生服务调查和卫生部常规死因登记报告系统等数据,利用二步模型法和人力资源法分别测算疾病直接经济负担、间接经济负担和总经济负担,并进行分类统计。结果1993年中国慢性非传染性疾病经济负担为1963.44亿元,占全部疾病总经济负担的58.84/,占GDP的5.67/;2003年中国慢性非传染性疾病经济负担达到8580.54亿元,占全部疾病总经济负担的71.45/,占GDP的7.31/。居慢性非传染性疾病总经济负担前5位的疾病是恶性肿瘤、脑血管疾病、高血压、其他类型心脏病、冠心病,其总经济负担合计为3393.53亿元,占慢性非传染性疾病总经济负担的39.55/;占全部疾病总经济负担合计的28.25/。人口老龄化导致明显“疾病堆积”现象。结论慢性非传染性疾病经济负担巨大且以高于GDP增长的速度增长,成为我国主要的疾病经济负担;恶性肿瘤、脑血管疾病、高血压、其他类型心脏病、冠心病是导致慢性非传染性疾病经济负担的主要原因;要从宏观经济和社会发展上警惕“疾病堆积”和“人口红利”,减少对将来社会带来的双重影响。     

Gender differences in determinants and consequences of health and illness

This paper uses a framework developed for gender and tropical diseases for the analysis of non-communicable diseases and conditions in developing and industrialized countries. The framework illustrates that gender interacts with the social, economic and biological determinants and consequences of tropical diseases to create different health outcomes for males and females. Whereas the framework was previously limited to developing countries where tropical infectious diseases are more prevalent, the present paper demonstrates that gender has an important effect on the determinants and consequences of health and illness in industrialized countries as well. This paper reviews a large number of studies on the interaction between gender and the determinants and consequences of chronic diseases and shows how these interactions result in different approaches to prevention, treatment, and coping with illness. Specific examples of chronic diseases are discussed in each section with respect to both developing and industrialized countries.     

The uneven tides of the health transition

As spectacular mortality reductions have occurred in all developing nations at all national income levels, the epidemiologic transition theory suggests that cause-of-mortality patterns should shift from communicable diseases especially prevalent among infants and children to problems resulting from non-communicable conditions at older ages. Global estimates confirm this expectation, and mortality from these latter conditions has become predominant worldwide, leading some observers to argue for a corresponding shift in the public health agenda. In this paper, we nuance this finding by studying the important poverty-gradient concealed in the global estimates. Our results demonstrate the remaining cause-of-death disparities between the world's poorest and richest populations. We find that the poorest population (1st quintile) experiences higher mortality than the richest population (5th quintile) in each of the three main groups of mortality causes but that the excess mortality of the poorest population is mostly due to the higher incidence of communicable diseases (77% of excess deaths). Overall, those diseases only account for 34.2% of deaths in the world but still dominate mortality causes among the poorest 20% of the world population (58.6% of all deaths). Moreover, these results appear robust to alternative estimates of the international distribution of the world's poorest people. While recognizing the emerging agenda of the non-communicable conditions, we thus underscore the "unfinished agenda" of communicable diseases in many countries. As populations affected by these diseases are predominantly among the poorer, equity considerations should caution against a premature shift away from these diseases.     

Public health in Thailand: emerging focus on non-communicable diseases

Over the past three decades, the public health landscape in Thailand has shifted remarkably. Currently chronic non-communicable diseases represent the largest cause of mortality in the Thai population. In light of the current situation, this paper synthesizes what is known about the chronic non-communicable disease situation in Thailand and analyzes current policy responses. Relevant contextual factors such as socio-economic transitions, health systems development, and health workforce capacities are also considered. Primary data for this study were collected by a review of policy documents, government statements, and statistics reported by the Thailand Ministry of Public Health. Secondary data were obtained by a thorough review of the existing literature. The paper finds that while current policy responses to chronic non-communicable diseases in the health sector have focused on improving prevention and control of risk factors, a stronger emphasis on chronic disease treatment and management may be needed in the future. The paper concludes with an exploration of the potential for developing and implementing realistic public health responses to the growing burden of chronic non-communicable diseases in a Southeast Asian country context by utilizing existing capacities in research, policy, and health workforce development.     

Forecasting chronic disease risks in developing countries

Declining fertility and infant mortality has caused the population in many developing countries to age. Population ageing can produce a rapid shift in the predominant public health problems from infant mortality and infectious diseases to chronic disease mortality at later ages. Designing public health strategies to deal with the health consequences of population ageing in developing countries is difficult both because of a remaining burden of infectious diseases and because of changes in life style associated with economic development that may raise chronic disease risks. Because there are few longitudinal studies of chronic disease risks in developing countries, we investigate the use of a planning and forecasting model, which combines data from multiple sources, in six developing countries.     

Effect of maternal diet on the epigenome: implications for human metabolic disease

The rapid increase in the incidence of chronic non-communicable diseases over the past two decades cannot be explained solely by genetic and adult lifestyle factors. There is now considerable evidence that the fetal and early postnatal environment also strongly influences the risk of developing such diseases in later life. Human studies have shown that low birth weight is associated with an increased risk of CVD, type II diabetes, obesity and hypertension, although recent studies have shown that over-nutrition in early life can also increase susceptibility to future metabolic disease. These findings have been replicated in a variety of animal models, which have shown that both maternal under- and over-nutrition can induce persistent changes in gene expression and metabolism within the offspring. The mechanism by which the maternal nutritional environment induces such changes is beginning to be understood and involves the altered epigenetic regulation of specific genes. The demonstration of a role for altered epigenetic regulation of genes in the developmental induction of chronic diseases raises the possibility that nutritional or pharmaceutical interventions may be used to modify long-term cardio-metabolic disease risk and combat this rapid rise in chronic non-communicable diseases.     

Affordability, availability and acceptability barriers to health care for the chronically ill: Longitudinal case studies from South Africa

Background  

There is an increasing burden of chronic illness in low and middle income countries, driven by TB/HIV, as well as non-communicable diseases. Few health systems are organized to meet the needs of chronically ill patients, and patients' perspectives on the difficulties of accessing care need to be better understood, particularly in poor resourced settings, to achieve this end. This paper describes the experience of poor households attempting to access chronic care in a rural area of South Africa.