The Globalization of Disease

http://www.brookings.edu/press/review/fall2001/barks-ruggles.htm

In a bold speech in early June marking the 20th anniversary of the first report of HIV/AIDS, United Nations Secretary General Kofi Annan called on the private sector as well as donor governments to contribute to a $7–10 billion global trust fund to combat HIV/AIDS, malaria, and tuberculosis. His call for action to the business community was based on a sensible dose of "enlightened self-interest."

Annan warned that AIDS leaches profits out of economies and businesses and raises new barriers to development and economic growth. He cautioned that the widening gaps between wealthy and poor, which AIDS and other diseases are expanding, could accelerate the growing backlash against globalization. While global markets have created unprecedented economic opportunities and growth, the benefits have not been equally distributed, and the risks—especially the health risks—of an increasingly interlinked and interdependent world have not been thoroughly considered.

As trade, travel, and food sources become more global, humans, animals, and plants are being exposed to myriad new and ever more resiliant diseases. Increasingly antibiotics fail to subdue multi-drug-resistant forms of diseases, such as tuberculosis, that they once nearly eliminated. Although there is no agreement on what is causing this trend—theories include climate changes, manipulation of plants and animals, genetic engineering, increased mobility of humans and food sources, and terrorism—the fact remains that disease threats are increasing. Officials in the United States and the internationalcommunity need to begin containing the threat that diseases and pests pose in an increasingly globalized world, by putting into place reliable, cooperative, and responsive systems to anticipate, prevent, detect, and react to outbreaks—both those caused inadvertently and those caused by terrorist attack.

Old and New Disease Risks

In December 1999 the National Intelligence Council released an unprecedented unclassified assessment of the threat that new and reemerging diseases pose to the United States and other countries. The report highlighted a few key facts. First, infectious diseases are a leading cause of death worldwide, accounting for one-quarter to one-third of all deaths globally in 1998. Second, 20 diseases that had been in decline reemerged or spread geographically between 1973 and 1999, including new multiple-drug-resistant strains of tuberculosis, malaria, and cholera. And third, 29 previously unknown diseases were identified in the same period, including HIV/AIDS, Ebola, and hepatitis C. There are no cures for many of these diseases.

The United States, despite its sophisticated medical care and infrastructure, has not been immune to this trend. Between 1980 and 1999, deaths due to infectious diseases doubled. Multiple-drug-resistant forms of TB and staphylococcus alone kill more than 14,000 Americans annually. HIV/AIDS is experiencing a resurgence, especially among minorities and women. In 1999, new HIV infections rose from 40,000 annually to 46,000, according to the Institute of Medicine. However, only 70 percent of Americans infected with HIV know their sero-status, and many who do know are failing to protect and educate themselves. Unprotected sex in some high-risk gay communities has risen to 50 percent, and a survey released by the Centers for Disease Control (CDC) in December 2000 found that 40 percent of the 5,600 Americans questioned believed that AIDS could be transmitted by sharing a glass with or being coughed on by an infected person.

Though some lessons have been learned from the struggle against HIV/AIDS, the U.S. health care system is ill equipped to deal with large-scale outbreaks of new or rare diseases. As evidenced by the outbreak of West Nile virus in New York in August 1999, an unknown and relatively weak virus can easily gain a foothold and quickly spread. Although only 82 people had been infected by the end of 2000 and only 8 had died, more than 4,000 birds and 59 horses had tested positive or died from the virus. Even though the CDC alone spent nearly $10 million in 1999 and 2000 to contain West Nile virus, it spread from 3 states in 1999 to 12 states and the District of Columbia by the end of 2000, and its spread continues.

Crops and Animals at Risk

The risks posed by new and reemerging diseases are not limited to humans. Crop and livestock diseases can exact steep health and economic costs. As seen during recent disease outbreaks in Europe, global trade's transfer of products, animals, and people around the world can speed the spread of infection. The British government anticipates paying around 1 billion pounds to farmers in compensation for culling animals potentially exposed to foot-and-mouth disease. With large parts of the countryside closed to both foot and vehicle traffic, losses to Britain's tourism industry are expected to top 5 billion pounds. More than 4.5 million animals in Britain have been slaughtered, and others have been killed in France, the Netherlands, and other European countries where the disease spread. Likewise, in Britain, bovine spongiform encephalopathy (BSE or "mad cow" disease) killed nearly 200,000 cattle. Nearly 5 million more were preemptively slaughtered. As of last November, 90 people had died from variant Creutzfeldt-Jakob Disease (vCJD), a malady linked to eating animals infected with BSE. By December, the cost of BSE in the United Kingdom alone was estimated by the British government to exceed 1.5 billion pounds.

The United States is the world's largest food producer and exporter. Agricultural products contributed more than $97.2 billion to the U.S. economy in 1997, and the Agriculture Department estimates that farm exports alone contributed more than $49 billion to the U.S. economy in 1999. The potential for harm to the nation's agricultural industry from alien pests and diseases is enormous.

Lethal Tourists and Cargo?

According to the Agriculture Department, the number of passengers traveling to the United States increased from 27 million in 1984 to 66 million in 1996. More than 400 million U.S. border crossings were recorded in 1996, and in 1998 more than 422,000 cargo-bearing aircraft were inspected on landing in the United States. This flood of people and goods has exacerbated the already difficult job of controlling who and what enters and exits the nation. Each incoming passenger and cargo load could harbor new and deadly diseases or pests. With the increasing globalization of American food sources, including snow peas from Guatemala, apples from Chile, and mangoes from India, the threat from diseases and pests to American crops and people is growing. According to the Department of Commerce, farm imports into the United States increased 65 percent between 1991 and 1999, and that trend is expected to continue as the food supply becomes more global.

In addition, invasive species—both plant and animal—that are controlled or balanced in their native environments increasingly threaten indigenous species in the United States. Conservation researchers cited by the Agriculture Department have found that invasive alien plant infestations cover more than 100 million acres in the United States and are spreading at the rate of 14 percent a year. The department estimates that its agents intercept more than 1.8 million illegal agricultural products a year, stopping more than 52,000 plant and animal pests and diseases from entering the United States. But inspecting bags and cargo and destroying their contents may not keep out viruses and bacteria. Carried by humans, animals, plants, soil, foodstuffs, water, and the very planes and ships that bring foreign people and products to the United States, some diseases do not wait to pass inspection.

Are Diseases Gaining the Upper Hand?

Scientists working on human, animal, and plant diseases all agree that the number of new diseases, the increasing resistance of known diseases, and the rapid geographic spread of both are on the rise. What they do not agree on is why. Theories include climate changes, human manipulation of plant and animal food and genetics, increasing travel of humans and some animals (especially animals used for food), as well as deliberate introduction. No one theory has been proven or eliminated, but policymakers must take seriously the threat posed by the spread of disease to human, plant, and animal health, as well as the implications for economies and food security. Putting in place prevention, mitigation, and disaster-response systems now may help avoid a catastrophe later.

Is the United States Prepared?

What would happen to America's economy and health care infrastructure if a virulent and communicable human, animal, or plant disease entered the United States and gained a foothold? The worst-case scenario would be the introduction of a devastating disease by a terrorist group.

In May 2000, three mid-size U.S. cities (Portsmouth, New Hampshire; Denver, Colorado; and Washington, D.C.) took part in a large-scale exercise spanning several days to see how local, state, and national emergency systems would respond to three potential disasters—nuclear, biological, and chemical attacks by terrorists. The biological attack scenario, played out in Denver, showed that most local and regional authorities, even those who had been specially trained, were underprepared to deal with a large communicable disease outbreak and were overwhelmed by the complex coordination, decisionmaking, and management needed to contain and control the spread of disease. When the scenario ended (after four days), between 950 and 2,000 people had "died" and the disease had spread throughout the United States and to other countries.

While being prepared for a possible terrorist attack is important, the more insidious threat to the American economy and the safety of its citizens is the daily, routine transportation of goods, products, and people, along with the diseases and pests they carry, across borders. Constructing robust, multi-agency systems to identify, eliminate, and control "normal" disease and pest outbreaks will lower that quotidian threat, while at the same time building a foundation of skilled individuals and systems to help prevent and respond rapidly to a potential biological terrorism event.

What Needs to Be Done?

Recognizing and assessing U.S. vulnerabilities in protecting against, containing, and treating diseases is the first step toward building a comprehensive system to lower the risk of disease outbreaks. The Denver exercise, for example, was part of an ongoing training effort that exposed the need for greater coordination in decisionmaking, communication, and emergency relief efforts. The West Nile virus has likewise proved the value of increased training and coordination among health, animal, and plant disease authorities. After people started falling sick from a mysterious encephalitis infection, animal control authorities began investigating increased crow deaths in the same region. They discovered that crows also die from the West Nile virus and may facilitate its spread. The Agriculture Department has begun to assess its own infrastructure and training gaps, and its Animal and Plant Health Inspection Service is now constructing an emergency management center to handle disease outbreaks in U.S. plants and animals.

These efforts, however, are but the first steps to put in place a strengthened system to detect and deter both deliberate terrorist attacks and unintentional transmission. Increased training in diagnostic techniques, better communication networks between and among health and emergency response personnel and the scientific community, and increased resources for enforcement, protection, prevention, and education programs are needed.

Beyond America's Borders?

The threat to the United States does not, however, end at the border. Many diseases originate overseas. The EU, the United States, and other concerned nations should begin to work with international organizations on a range of efforts to identify, contain, and control new and drug-resistant diseases in humans, animals, and plants, and to mitigate the damage they cause. In the long term, an international effort should include agreements on disease identification, containment, and treatment, and standard protocols and cost-sharing structures to ensure that poor and rich countries alike can control outbreaks of the most deadly diseases. A global surveillance network to help identify and eliminate diseases in their countries of origin should also be considered. Cooperative efforts must also be undertaken to construct functioning primary health care systems and infrastructure in developing countries so that diseases originating in the tropics can be identified and eradicated before they spread. Such an effort, through improving access to primary care and vaccinations, would improve the health of children and their chances of obtaining an education. Better education, better health, and other opportunities could spur development and economic growth over the long term.

Short-term international efforts should focus on immediate threats and build foundations for long-term efforts. World health leaders could set up internationally recognized and endorsed standard protocols for human vaccine development and testing for HIV/AIDS, malaria, and other killer diseases, along with systematic plans for comparative trials of multiple vaccines against them. They should commit to the rapid eradication of diseases that have not yet developed resistance to standard treatments, including polio, measles, river blindness, and Guinea worm. (Polio cases have fallen 99 percent in the past 13 years since the launch of the Global Polio Eradication Initiative, but polio must be eliminated in the 20 countries where it still exists.) Public-private partnerships could accelerate development of new disease treatments. (Some possibilities include tax incentives to encourage companies to manufacture medications for diseases that affect primarily poor countries, and trust funds to guarantee a profit for the manufacturers of medicines to treat third-world diseases.) International intellectual property rights regimes should be reformed to ensure that essential drugs and medicines are more affordable for all people. Genetically diverse plant and animal species should be preserved to increase the genetic pool on which researchers can draw to find disease-resistant qualities. Scientists, medical professionals, and disease specialists should have better access to distance learning, training, and exchange programs to increase understanding of and best treatments for diseases.

The fight against diseases was largely considered over as recently as the 1970s, but as fast as health professionals learn to treat them, diseases are fighting back. Increased travel and trade are accelerating these trends. Winning the fight against disease and protecting the world's health, economies, and food supplies will require coordination, cooperation, and resources. As has been shown time and again during vaccination campaigns in war zones, even people trying to kill each other will agree to a temporary cease-fire to save their children from disease. If the world can build on that model of cooperation, perhaps there is a chance to win this war-and in the process create the hope of cooperation in other areas as well.