Washington Post / By Ellen Silbergeld / Sunday, March 18, 2001
For the past few years, we have been witnessing an agricultural holocaust in the original sense of that term -- burnt animal sacrifice. Last month's outbreak of foot-and-mouth disease in Britain, which authorities are saying could lead to the incineration of up to 1 million farm animals, follows upon mad cow disease in several parts of Europe, and Nipah virus among pigs in Indonesia -- all fresh evidence of the increased power and mobility of the microscopic agents of disease that threaten our food supply and, in some cases, our health.
We humans are in many ways a species of Gullivers, bound and occupied by an army of the very small organisms that really rule this planet. Viruses, bacteria and parasites have been joined by the recently recognized and still mysterious prions (the proteins responsible for mad cow disease) to comprise a micro-army that can bring down economies, country by country. The world is a fully globalized marketplace for the very small. National borders can constrain trade in goods and currency, but they are useless against disease. Pathogens move freely and widely, carried by travelers, humans and others, as well as by the wind. They hitchhike across continents in animal feed , as the foot-and-mouth virus seems to have done; they cross oceans, as the West Nile virus did, apparently taking advantage of the coincident movement of an Asian mosquito and an African bird; they shuttle up and down continental coasts on ocean currents, as the toxic algae did, bringing death to more than 400 sea lions in California's Monterey Bay in 1998.
We must realize that we cannot block diseases by closing borders, by signing or banning trade agreements, by national policies or by local practice. We must fashion a global response to a global problem. Antiglobalism must give way to a planetary perspective on public health.
In many ways, we have brought these problems on ourselves. While we have arranged the natural world to suit our needs, increasingly our arrangements suit the convenience of our small enemies. Long before the development of molecular biotechnology, we perfected the practice of carefully selecting plant and animal strains that grow where and when we want them, without consideration of the risks of inbreeding on their resistance to disease. By standardizing around one strain, we discard the evolutionary virtues of hybrid vigor. A diverse population is far more likely to survive disease -- a lesson we should have learned more than 150 years ago after blight destroyed a staple crop, causing the Irish potato famine.
We have augmented other opportunities for the very small by concentrating ourselves and our food in smaller spaces. We increasingly recycle waste products in animal feed, even after mad cow disease alerted us to the danger of adding the remains of dead sheep and cows to cattle feed. We ourselves drink water that has already gone through several other people before it reaches our taps.
Most alarmingly, we are disabling our best defenses against pathogens by the profligate use of antibiotics. Bacteria can develop resistance to any antibiotic, given sufficient use. Late last year, the Food and Drug Administration proposed banning the use of a class of antibiotics known as fluoroquinolones in poultry, citing increases in resistance to that drug in campylobacter, a food-borne pathogen that can cause diarrhea in humans. The ban was accepted by one manufacturer, Abbott Laboratories, but the other, Bayer, is contesting the need for restrictions, which already have been proposed or implemented in several European countries and Australia.
Given the many interests at stake -- from individual health to big business and national economies -- what is a reasonable response to these waves of agricultural outbreaks and to the more subtle but more immediately dangerous problem of drug resistance?
The European Union is currently applying the Edgar Allan Poe strategy: Each country is shutting its castle gates against the "red death" at its borders, killing animals where foot-and-mouth disease rages or may yet rage, banning import of beef products where the transmissible spongiform encephalopathies responsible for mad cow have and have not been detected. Given our imperfect systems of monitoring and the long incubation times of many diseases, these policies can never prevent the spread of infection.
Some officials, including Germany's new minister for agriculture, Renate Kuenast of the Green Party, propose to lock out the rest of the world, calling for a return to primitive agrarian communities that consume only what they can locally grow. For urbanized societies that have grown dependent upon the world's bounty, this is hardly feasible.
Still another response is the "burn the witch" policy: If the world is swarming with pathogens, then kill them all; deploy antibiotics, antimicrobials, disinfectants in everything we build and use. There is a huge market of "antibacterial" soaps available in the United States; and it is possible, amazingly and improvidently, to purchase bathroom fixtures impregnated with antimicrobial chemicals. All of these bring with them the risk of increased antibiotic resistance.
Rather than killing animals from countries with identified outbreaks of disease, we need to globalize national systems of food safety and food animal monitoring. Rather than spraying tourists with disinfectant, as the United States has started to do to travelers from the EU, we need to harmonize inspections and regulations at ports before disease breaks out. Rather than seeing food safety as separate from environmental concerns, we need a consistent and prudent policy to restrain the use of antibiotics.
The United States has been a leader in the movement to improve disease surveillance so far. The Emerging Infectious Diseases Network, organized by the Centers for Disease Control and Prevention (CDC), is a model for the rest of the world. Its capacity to monitor and track new pathogens is what helped U.S. scientists counter West Nile virus quickly and effectively after it was first identified in the Western hemisphere 1 1/2 years ago. The CDC continues to coordinate national surveillance of that disease in mosquitoes, birds and humans. That attention to the emergence and movement of new pathogens must be adopted and supported worldwide, if only for our own protection. Such international organizations that do exist to coordinate global health and food safety -- the World Health Organization and the Food and Agriculture Organization -- have too often become the targets of antiglobalists from Jesse Helms to Ralph Nader.
We need to be as global as the viruses, as persistent as prions and as adaptable as the bacteria. We need more globalism, not less, if we are to make the world safer for us to live out our lives in recognition of what we really are -- the hosts of the very small. They own our planet, and we pretend otherwise at our peril.
Ellen Silbergeld is a professor of epidemiology and toxicology at the University of Maryland Medical School.
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