Economic Development and Infectious Disease
Economic Development and Infectious Disease
History and Scientific Foundations
Introduction
Across the nations of the world, there is a relationship between income and health. Developed nations often have lower average morbidity (illness) and mortality (death) rates than developing nations. Mortality rates drop over time as countries increase in wealth. Within countries, wealthier people typically live longer than poorer people.
History and Scientific Foundations
The impact of economic conditions on health status has long been recognized, based on studies of the effects of food scarcity, shelter, and living space. Although economic conditions have been de-emphasized as factors in mortality and morbidity because of the dissemination of medical technologies, there is increasing evidence that this diffusion of health knowledge and technology has had differential effects in developed and underdeveloped nations. Studies of this topic typically focus on national income (the value of all goods and services produced in a given period). Secondly, per capita income (income per person) is the leading indicator of economic development and motivates many health policy decisions. Thus, many observers are calling for greater global economic development. Critics assail the emphasis on economic development over public health, but others assert that public health initiatives are too often thwarted by political and economic instability and food scarcity.
Studies have found a significant positive correlation between income and health status in both developed and developing economies. In more developed countries, the causal path typically goes from health status to income, with feedback from income to health. Healthier people are wealthy, but wealthy people may have increased access to healthcare and wellness resources. However, whether income “buys” better health and just how this may occur has proven difficult for economists to quantify, especially for adults in the work force. In developed countries, the most documented connection between income and health is based on studies of infant mortality rates, the scope of which cannot support a robust analysis of the feedback from health to income.
The mechanisms producing a relationship between money and health are complex. Variables such as race, education, and urban or rural status may also influence income or health for many individuals. The causes of poor health status in less developed countries may be different from the factors that undermine health in industrialized countries. In developing countries, infectious disease, lack of clean drinking water, and inadequate diet may present the greatest public health risks. In developed nations, lifestyle-related chronic diseases and reduced physical activity may present the greatest public health threats.
The connecting mechanisms underlying the relationship between health and income are sometimes not specific to the level of industrialization. This relationship in “middle income” or transition economies may be particularly hard to analyze because persons in the same communities, and even in the same households, can be disproportionately affected by problems common to both developed and less-developed regions. For example, obese women may be neighbors or even housemates of malnourished children. Thus the scientific underpinnings of the relationship between development, income and health are best served by focusing on universal mechanisms—such as psychosocial stress (stress caused by social, psychological, and environmental factors)—that are likely to be found in every society and community.
A study of data sponsored by the World Health Organization (WHO) summarized below that confirms a link between income and health casts light on the interplay between wealth and health. In particular, the study focused on how income improves health apart from the availability of medical services. The study results indicate that increased earnings capacity, along with policies that provide for income transfers to those less wealthy, may be as important for health outcomes as additional funds for service provision. Within countries, income is strongly correlated with health outcomes, especially in settings where the health services delivery is weak. This correlation exists apart from the presence of vital public health campaigns to provide clean water, eradicate malaria, vaccinate children, or deliver AIDS treatment drugs in developing countries.
In view of the possible independence of income as a factor in improving health, a question arises regarding the efficiency of public and private funds aimed at health promotion. For example, investment in economic development, employment opportunities and income support for the poor might have equal or greater impact on health than would public expenditures on health services availability. People with more income may spend income on goods and services associated with better health—more nutritious food, better housing, exercise, or leisure activities.
WORDS TO KNOW
MORBIDITY: The term “morbidity” comes from the Latin word “morbus,” which means sick. In medicine it refers not just to the state of being ill, but also to the severity of the illness. A serious disease is said to have a high morbidity.
MORTALITY: Mortality is the condition of being susceptible to death. The term “mortality” comes from the Latin word mors, which means “death.” Mortality can also refer to the rate of deaths caused by an illness or injury, i.e., “Rabies has a high mortality.”
PATHOGEN: A disease causing agent, such as a bacteria, virus, fungus, etc.
Applications and Research
The impact of improved pensions on health in South Africa
A “natural experiment” reported by Princeton University that illuminated the relationship between income and health dealt with the institution of larger pension payments to all elderly South Africans. To determine whether income has a causal effect on health, WHO-sponsored investigators identified state old-age pension payments as a source of income that is not determined by a respondent's health status. According to the report, in South Africa, women aged 60 and older and men aged 65 and older are eligible for a monthly cash transfer, if they do not have an employer-based pension, and over 80% of eligible people take up this source of income, which in many communities, where unemployment reaches up to 40%, is the only stable and considerable source of income.
The health survey showed that pension income had a protective effect on the self-reported health of all adults in which the pension income was pooled with that of other household members. For pensioners living in households in which income was not pooled, the beneficial health effects of the pension accrued only to the pensioners, after they started receiving the pension. These effects persisted regardless of geographic location, race, educational level, and income level.
The researchers investigated whether higher income tended to have an impact on four major areas of daily life: medical care, water and sanitation, nutrition, and psychosocial stress. They found no evidence from the survey data suggesting that higher incomes enabled respondents to spend more time and money seeking out better health services such as private physicians and better equipped clinics. Also, access to cleaner water was apparently not improved, although higher and pooled income families were more likely to have a flush toilet. However, higher and pooled income families were more likely to report improved nutrition and fewer skipped meals, which were correlated with better health status. Finally, income was correlated with reduced self-reported depression symptoms connected to psychosocial stress. Depression has been associated with increased all-cause medical symptoms in many studies. Thus the researchers concluded that income has a causal effect on health status, which is mediated by a combination of improved sanitation, nutrition, and the reduction of psychosocial stress.
Impacts and Issues
Social inequality and infectious disease
Evidence is mounting that social inequalities contribute significantly to disease emergence. These inequalities have impacted not only the distribution of infectious diseases, but also the severity and outcome of disease in affected persons. Analyses of outbreaks of Ebola, AIDS, and tuberculosis indicate that disease emergence is influenced by specific events and processes, subject to local variation. Close examination of mutations in microorganisms often shows that human actions have been key factors in increasing the spread of disease and resistance to antibiotics. For example, tropical diseases such as malaria generally affect people in lower socioeconomic brackets, while people with higher incomes may purchase mosquito nets, insect repellants, or live in areas with better drainage and fewer mosquitoes.
The distribution of Ebola outbreaks affect (apart from researchers) people living in poverty and health care workers who serve the poor, but often not others in close physical proximity. For example, the 1976 outbreak in Zaire affected 318 persons. The cases could be traced to failure to follow contact precautions and improper sterilization of syringes and other equipment and supplies. Once these measures were taken, the outbreak was terminated. This explanation suggests that Ebola does not always emerge randomly. Rather, the likelihood of coming into contact with unsterile syringes in, for example, health clinics, is inversely proportional to social status. Population groups with access to high-quality medical services are thus unlikely to contract Ebola even in Ebola affected regions.
The reemergence of tuberculosis is another powerful example of the impact of social inequality on the epidemiology of infections. For decades the disease was largely absent Western Europe and North America, but remained endemic in many developing and underdeveloped nations worldwide. World trade, increased migration, and international travel have reintroduced tuberculosis to regions where the disease had once been eliminated.
Thus, socioeconomic (social and economic factors considered) inequality within nations may have helped foster the virulence of old and new infectious diseases. Economic inequality between nations may also accentuate differences in the distribution of infectious diseases. National borders cannot keep out all pathogens (diseasecausing organisms), but can be substantial boundaries to infectious disease response and the provision of healthcare.
Economic development's impact on tuberculosis in India
Approximately a half-million people in India die of tuberculosis annually. Until recently, fewer than 50% of people with tuberculosis received an accurate diagnosis. Less than half of these people received effective treatment. A study by the Ministry of Health and Family Welfare analyzed the impact of health policies promulgated in 1993 that devoted increased resources such as improved diagnosis, case management of treatment, and the use of uniform anti-tuberculosis treatments as well as improved case reporting methods. The program trained more than 200,000 health workers and improved access to services for 436 million people (more than 40 percent of India's population). Under the program's auspices, about 3.4 million patients were evaluated for tuberculosis, and nearly 800,000 had received treatment by late 2001, with a success rate greater than 80 percent. Thus India's tuberculosis-control program has succeeded in improving access to care, the quality of diagnosis, and the probability of successful treatment. This has translated into the prevention of 200,000 deaths and the alleviation of indirect medical costs (e.g., productivity and caregiving costs) of more than $400 million—an order of magnitude greater than the cost of program implementation.
In spite of the program's success, ministry officials observe that it will be a challenging to sustain and expand the program due to the country's current limited primary health care system and large—but mainly unregulated— private health care system. Furthermore, India struggling with an increase in incidence of HIV and multi-drug-resistant tuberculosis.
The advance of public health systems and spread of advanced medical knowledge and technology has certainly resulted in improvements in the health status worldwide. However, lack of economic development and vast income inequalities across and within national boundaries continue to present major obstacles to public health. Poverty has prevented equality in healthcare among nations. Infectious diseases continue to be the major cause of death worldwide, with 25% of all deaths and 30% of the global disease burden attributed to communicable diseases. More than 95% of these deaths, the majority of which are preventable, occur in the poorest areas of the developing nations. HIV/AIDS, tuberculosis, and malaria are the three most lethal infectious diseases in these regions.
Health assistance to developing countries, especially for these three diseases, has been based on advocacy for the principles of social justice and the human right to health in the developing world. Given the increasing integration of the global economy, economic development in lower income countries will increase profitable investment opportunities for wealthier countries in the developing world. Improved public health in developing countries also has political and international security benefits for developed nations.
Primary Source Connection
The following press release from the World Health Organization (WHO) outlines the economic impacts of malaria, including the costs on present generations for past failures to more significantly control the disease.
Economic Costs Of Malaria Are Many Times Higher Than Previously Estimated
AFRICA'S GDP WOULD BE UP TO $100 BILLION GREATER THIS YEAR IF MALARIA HAD BEEN ELIMINATED YEARS AGO, ACCORDING TO NEW RESEARCH BY HARVARD, LONDON SCHOOL AND WHO.
Abuja, Nigeria—The control of malaria in Africa would significantly increase the continent's economic productivity and the income of African families, according to the findings of a new report released today by the World Health Organization, Harvard University and the London School of Hygiene and Tropical Medicine.
“The evidence strongly suggests that malaria obstructs overall economic development in Africa,” said Dr. Jeffrey Sachs, Director of the Center for International Development at Harvard University. “Since 1990, the per person GDP in many sub-Saharan African countries has declined, and malaria is an important reason for this poor economic performance.”
According to statistical estimates in the report, sub-Saharan Africa's GDP would be up to 32% greater this year if malaria had been eliminated 35 years ago. This would represent up to $100 billion added to sub-Saharan Africa's current GDP of $300 billion. This extra $100 billion would be, by comparison, nearly five times greater than all development aid provided to Africa last year.According to the report, malaria slows economic growth in Africa by up to 1.3% each year. This slowdown in economic growth due to malaria is over and above the more readily observed short run costs of the disease. Since sub-Saharan Africa's GDP is around $300 billion, the short-term benefits of malaria control can reasonably be estimated at between $3 billion and $12 billion per year. “Malaria is hurting the living standards of Africans today and is also preventing the improvement of living standards for future generations,” said Dr. Gro Harlem Brundtland, Director General of the World Health Organization. “This is an unnecessary and preventable handicap on the continent's economic development.”
The report also finds that:
- Malaria-free countries average three times higher GDP per person than malarious countries, even after controlling for government policy, geographical location, and other factors which impact on economic well-being.
- One healthy year of life is gained for every $1 to $8 spent on effectively treating malaria cases, which makes the malaria treatment as cost-effective a public health investment as measles vaccinations. This analysis, carried out by Dr. Ann Mills, LSHTM, demonstrates that malaria control tools and intervention strategies provide good value for money.
“Malaria is taking costly bites out of Africa,” said Dr. David Nabarro, executive director at WHO. “It is feasting on the health and development of African children and it is draining the life out of African economies.”
The report recommends that $1 billion annually be devoted to malaria prevention and control and that most of this expenditure be focused in Africa. This is many times greater than the amount which is currently being spent. It argues that spending this amount is economically justifiable as the short-term benefits of malaria control can reasonably be estimated at between $3 billion and $12 billion per year.
“The benefits of committing substantial new economic resources to malaria will greatly exceed the costs,” said Sachs.
The findings of the report will be presented today at the first ever summit to focus on malaria. The heads of state of twenty African nations and the executive directors of the African Development Bank, World Bank, UNDP, UNICEF, UNESCO and WHO are expected to be present to hear the findings. The Summit is being hosted in Abuja, Nigeria by the country's president, His Excellency Olusegun Obasanjo, and is co-sponsored by WHO.
Malaria accounts for nearly one million deaths each year in Africa; an estimated 700,000 of these deaths are among children. Research has found that the wider availability and use of insecticide treated bednets would result in 50 percent less malaria illness among children. Yet presently, only 2% of African children are protected at night with a treated bednet.
“Roll Back Malaria aims to help African families create a mosquito free zone in the home through the use of nets, drapes, or bednets treated with insecticide,” said Dr. Awash Teklehaimanot, acting project manager for Roll Back Malaria. “Our goal is to ensure that every person at risk of malaria in Africa is protected with an insecticide-treated bednet within the next five years.”
In addition to ensuring wider availability of treated nets, Roll Back Malaria is also working to provide greater access to rapid diagnosis and quick treatment with the appropriate therapies—ideally in the home; preventing malaria illness during pregnancy; and detecting and responding to epidemics quickly.
“Halving the burden of malaria is realistic and achievable,” said Dr. Gro Harlem Brundtland, Director-General of WHO. “We have the tools. We have the economic justification. We now need leaders from both the public and private sectors stepping forward to make this happen.”
World Health Organization
WORLD HEALTH ORGANIZATION (WHO). “ECONOMIC COSTS OF MALARIA ARE MANY TIMES HIGHER THAN PREVIOUSLY ESTIMATED” PRESS RELEASE. APRIL 25, 2000.
See AlsoDeveloping Nations and Drug Delivery; Public Health and Infectious Disease; World Trade and Infectious Disease.
BIBLIOGRAPHY
Books
Lopez, Alan, Colin Mathers, and Majid Ezzati. Global Burden of Disease and Risk Factors. World Bank Group, 2006.
Periodicals
Adler, Nancy E., and Joan M. Ostrove. “Socioeconomic Status and Health: What We Know and What We Don't,” Ann N Y Acad Sci. (1999): 3-15.
Farmer, P. “Social Inequalities and Emerging Infectious Diseases.” Emerging Infectious Diseases Vol. 2, No. 4 (October-December, 1996).
Smith, J.P. “Healthy Bodies and Thick Wallets: The Dual Relationship between Health and Economic Status.” Journal of Economic Perspectives, 13 (2) (1999): 145-66.
Web Sites
United Nations. “UN Millennium Development Goals.” <http://www.un.org/millenniumgoals/> (accessed June 8, 2007).
Other Resources
Case, Anne, and Francis Wilson. “Health and Wellbeing in South Africa: Evidence from the Langeberg Survey,” mimeo. Princeton University, 2001.
Kenneth T. LaPensee