The Human-Animal Link

William B. Karesh and Robert A. Cook

From Foreign Affairs, July/August 2005

Summary:  Recent outbreaks of avian flu, SARS, the Ebola virus, and mad cow disease wreaked havoc on global trade and transport. They also all originated in animals. Humanity today is acutely vulnerable to diseases that start off in other species, yet our health care remains dangerously blinkered. It is time for a new, global approach.

William B. Karesh is Director of the Field Veterinary Program at the Wildlife Conservation Society and Co-chair of the World Conservation Union's Veterinary Specialist Group. Robert A. Cook is Vice President of and Chief Veterinarian at the Wildlife Conservation Society.

ONE WORLD, ONE HEALTH

In recent years, outbreaks of diseases such as avian flu, severe acute respiratory syndrome (SARS), the Ebola virus, and mad cow disease have frightened the public, disrupted global commerce, caused massive economic losses, and jeopardized diplomatic relations. These diseases have also shared a worrisome key characteristic: the ability to cross the Darwinian divide between animals and people. None of these illnesses depends on human hosts for its survival; as a result, they all persist today, far beyond the reach of medical intervention.

Meanwhile, humanity has become vulnerable to cross-species illnesses, thanks to modern advances such as the rapid transportation of both goods and people, increasing population density around the globe, and a growing dependence on intensified livestock production for food. The global transport of animals and animal products, which includes hundreds of species of wildlife, also provides safe passage for the harmful bacteria, viruses, and fungi they carry, not to mention the prion proteins that cause insidious illnesses such as mad cow disease and chronic wasting disease in deer and elk.

Adding to the risks is the fact that while many people in the developed world would scarcely recognize meat if it did not come wrapped in clear plastic, the vast majority of people on the planet today still slaughter animals for meat themselves or buy it fresh, salted, or smoked in open-air markets. These markets generally go uninspected by health officials, and consumers rarely have access to good health care, education on hygiene, common vaccines, or antibiotics.

Not only is local and national health care often a problem; internationally, no agency is responsible for, or capable of, monitoring and preventing the myriad diseases that can now cross the borders between countries and species. More specifically, no organization has the mandate to pursue policies based on a simple but critically important concept: that the health of people, animals, and the environment in which we all live are inextricably linked.

Thus, for example, the U.S. Department of Agriculture works to protect only the U.S. livestock industry and has scaled back the attention it pays to animals outside the United States over the last two decades. Despite new concerns about terrorist attacks on the U.S. food supply, Washington has still made little attempt to research and reduce diseases overseas before they reach U.S. shores. Nor does the United Nations direct the resources necessary to do a better job. The UN Food and Agriculture Organization, for example, is mandated to monitor the production of livestock and crops but does little to track threats to and dangers from wild plants and animals. The World Animal Health Organization has a volunteer committee that considers wildlife-related diseases, but it consists of just six people and meets only three days a year. And the World Health Organization (WHO) can only get involved in a country if officially invited, leaving it helpless to intervene in countries with governments that either do not know about or do not want to reveal the presence of a disease within their borders. The U.S. Centers for Disease Control and Prevention (CDC) must similarly wait for an invitation before extending their reach outside the United States.

What all this means is that no government agency or multilateral organization today focuses on the numerous diseases that threaten people, domestic animals, and wildlife alike. Nor does any one body collect and collate data from across the scientific spectrum, to ensure that health solutions are based on the input of professionals from all the various health fields working with humans, domestic animals, and wildlife.

Yet diseases pay no regard to the divisions among species or academic disciplines, and the failure to recognize this truth is placing humanity in great peril. As a recent outbreak of avian influenza reminded the world, what happens in one part of it -- and to one species -- can have a deadly serious impact on others. The planet clearly needs a new health paradigm that not only integrates the efforts of disparate groups but also balances their respective influences, to help bridge the gaps between them. This is especially so since the immediate effects of a particular illness are often the least of the problem. Diseases that attack people and animals also cause poverty and civil unrest, disrupt "free" ecosystem services such as drinking water and plant pollination, and threaten otherwise well-planned and sustainable economic development efforts, such as low-impact tourism. In short, the failure to adopt a planetwide and cross-species approach to health is getting costlier by the day; humanity cannot afford to pay the price much longer.

THE WORLD WE WERE GIVEN