Infectious Diseases and Global Change: Threats to Human Health and Security
Featuring John D. Eyles, Professor, McMaster University School of Geography and Geology; Director, McMaster Institute of Environment and Health;
Steve Lonergan, Professor, University of Victoria, Department of Geography;
and John E. Borrazzo, Environmental Health Advisor, Bureau of Global Health, USAID (discussant)
By Robert Lalasz
24 January 2002—Global environmental change and human activity are increasing human vulnerability to infectious diseases (IDs) and endangering our security, according to John Eyles, an expert in environmental health policy. Eyles addressed policymakers and practitioners in the latest meeting of the AVISO briefing series, which presents policy-friendly briefs on environmental change and human security issues. To read the full brief, click here.
The Antecedents and Consequences of Infectious Disease
John D. Eyles
Eyles began by recounting his recent work in Uzbekistan, where the disappearance of the Aral Sea and its impact on the local population have become what Eyles called one of the globe's worst contemporary environmental disasters. The destruction of the Aral ecosystem by the Soviet government has had profound consequences, ranging from the decimation of local fishing and agriculture to respiratory and kidney problems to the possible movement of fatal diseases and viruses from Redemption Island, where the Soviets tested biological weapons.
Eyles said that the Aral case is a dramatic example of how threats to human health are usually consequences of human activity. "For every action," he said, "there is a consequent reaction—perhaps unintended, but not unpredictable." In a similar way, he argued, IDs have become a major threat to global health, wealth, and security. And their distribution and spread also raises questions of justice and equity as they attack particular populations disproportionately, especially those living in poverty in the developing world. Yet IDs anywhere can have a global impact, said Eyles, through globalized trade and travel and the destabilization of strategic regions.
IDs: A Review
According to the World Health Organization (WHO), six diseases (pneumonia, tuberculosis, diarrheal diseases, malaria, measles, and HIV/AIDS) cause 90 percent of all ID deaths. Pneumonia particularly affects children, especially those born with low birth-weight and who are malnourished. Pneumonia, Eyles said, often coexists with diarrheal diseases, which themselves claim two million children under five annually.
Tuberculosis also kills two million people each year, and one-third of the world's population is infected with the TB bacillus. Eyles called TB's reemergence especially worrisome because (a) it is occurring in parts of the world (such as Eastern Europe) whose public health systems have been weakened by social and economic upheaval; and (b) because the strains of reemergent TB are more drug-resistant and linked to HIV/AIDS. As for HIV/AIDS, over 34.1 million people worldwide are living with the virus, with two-thirds in sub-Saharan Africa. "By early 1999, 11 million had died in sub-Saharan Africa of AIDS," said Eyles, "equivalent to the number that perished in the slave trade."
But the death toll from malaria far exceeds that of even AIDS-related mortality, killing a child somewhere in the world every 30 seconds. "Malaria for me is a sentinel to the consequences of human activity and their global impacts on human health," said Eyles. "While its effects have hit mainly poor people in rural areas, its reach is spreading. The building of infrastructure, the migration of people, changing weather patterns, global travel and trade create different reservoirs for mosquitoes to breed, making control difficult."
Ecological Change and IDs
Any ecological change can alter the relationships between humans and nature, said Eyles, altering microbial risk and threatening human health. "We have just borrowed the world from bacteria and viruses," he said. For example, the reemergence of Lyme's Disease in the Northeastern United States and the surge of hanta virus in the American Southwest and China have coincided with accelerated human development in those areas.
WHO, Eyles said, has identified two sets of hazards leading to this vulnerability: traditional, and modern. While traditional hazards are associated with a lack of development (such as poverty, lack of safe drinking water, and sanitation), modern hazards are associated with unsustainable development practices and include air, water, and soil pollution. These hazards, said Eyles, conspire "to ensure the conditions for the development and diffusion of infectious diseases around the world, especially in the developing world."
Eyles said that traditional hazards remain the main key to ID spread. IDs are "back with a vengeance" in India and sub-Saharan Africa, he said, because of pervasive malnutrition and a lack of funds or attention to basic health care, sanitation, and the elements of well-being. In addition, he said, intensive agricultural practices, dams, dikes, heavy industries, deforestation, migration, and increasing urbanization all have a hand in increasing susceptibility to IDs.
Security and Solutions
It would be a mistake to categorize IDs as a remote problem, said Eyles. IDs do not respect boundaries; as a recent ECSP policy brief discusses, an outbreak of the plague in India one day can have consequences in California the next. Eyles also pointed out that societies debilitated by disease cannot enter the world economy as full partners, and their populations may pose threats to our political security because they are denied things to which they feel entitled—such as adequate nutrition, shelter, clean air and water.
Some argue, Eyles pointed out, that the lending policies of such international finance organizations as the IMF may be crippling developing countries' abilities to invest in health and social services. He cited Zimbabwe as an example of a country that has tried (and failed) to meet IMF social spending reduction targets and yet which continues to significantly reduce its health care spending. Instead of offering fiscal solutions, Eyles said, the international community should be prioritizing public health and improving upon established programs. His specific recommendations included:
* Learning from and extending successful demonstration programs (such as the meningitis reduction in sub-Saharan Africa being carried out through partnerships with national governments, WHO, and nongovernmental organizations);
* Expanding inexpensive and effective ID control programs (e.g., treated bednets for malaria);
* Developing a surveillance and monitoring system for effective ID control (modeled on the WHO DOTS program for TB control);
* Funding more research to make linkages between global measurements of ID rates and local field studies;
* Strengthening health systems at the national and local levels through integrated policies that emphasize the importance of public health;
* Placing ID treatment on an equal footing with prevention.
* Extending G-20 deliberations beyond finance to include health.
Environment, governments, and equitable distribution matter for ID control, said Eyles. All three are crucial factors to include in the necessary programs of research, donor assistance, sustainable development, and trade relations. Without them, he said, we simply cannot achieve infrastructure changes in the environments that breed disease.
John Borrazzo of USAID emphasized several points from Eyles' talk that Borrazzo thought were crucial to effectively addressing the growing global ID problem:
* Stick with a strict public-health definition of IDs, and avoid using exotic and scary media conceptions. Prioritize chronic but less dramatic IDs such as malaria and diarrheal diseases.
* Remember that global change has many dimensions and implications for public health—the movements of peoples, goods, and ideas; population growth and demographic change; increasing urbanization; and climate change are just some of the factors that need to be considered.
* Marry public health prioritization to prompt diagnosis and treatment programs as well as to a commitment to reduce malnutrition and restore environmental health. The environmental burden of disease, said Borrazzo, is highest in sub-Saharan Africa and India—which is not surprising because environmental stress in these regions is also very great.
* Make health needs a part of the overall development dialogue and vice-versa.
* Understand that the impacts of IDs are highly inequitable within regions and countries. The poor suffer the most not only from the burden of disease, but also from the lack of health sector resources (including surveillance and control measures) available to them.
* IDs are important for the United States in terms of narrow self-interest, enlightened self-interest, and global leadership.
Traditional Hazards for ID Vulnerability: Traditional hazards are associated with a lack of development—they are related to poverty; lack of access to safe drinking water; inadequate basic sanitation in the household and community; indoor air pollution from cooking and using biomass fuel; and inadequate solid-waste disposal.
Modern Hazards for ID Vulnerability: Modern hazards are associated with unsustainable development practices, and include: water pollution from populated areas, industry, and intensive agriculture; urban air pollution from vehicular traffic, coal power stations, and industry; climate change; stratospheric ozone pollution (depletion); and transboundary pollution.
G-20: The G-20 is an international forum of finance ministers and central bank governors established in 1999 and representing 19 countries, the European Union, the IMF, and the World Bank. The G-20 studies policy issues among industrialized countries and emerging markets to promote international financial stability.