How You Gonna Keep ‘em Down on the Farm?
[San Francisco Medicine, April 2010]
by Steve Heilig, MPH, Director of Public Health and Education
Bacteria are likely the best creatures known for teaching and demonstrating evolution in action. They reproduce so fast and are so responsive to environmental selection pressures that one can alter a colony’s genetics in very little time. It’s literally a textbook case of Darwinian survival of the fittest.
Of course, that’s not always a good thing for other species. And with bacteria and antibiotics it has been war from the start. Drug-resistant strains and colonies began to arise as soon as antibiotics came online; the race to keep ahead of them is constant and escalating. In fact, Alexander Fleming, who discovered penicillin, warned about just this threat in his 1945 Nobel Prize address.
Efforts to develop new antibiotics, coupled with ever-vigilant efforts to refine prescribing to avoid unnecessary use, are crucial and ongoing. Still, at this point, antibiotic-resistant infections kill tens of thousands of Americans each year and have been estimated to cost the U.S. up to $34 billion annually. Brad Spellberg, MD, infectious disease specialist and author of Rising Plague, warns, “We are seeing infections ... that are literally resistant to every antibiotic that is FDA approved. These are untreatable infections. This is the first time since 1936, the year sulfa hit the market in the U.S., that we have had this problem.” Dr. Fred Tenover of the CDC added in Science in 2008 that “this is a major blooming public health crisis.”
As far back as the 1970s, some experts were warning that we were using too many antibiotics in agriculture; namely, as growth promoters and infection pro¬phylaxis in meat production. The concern was that this other reservoir of selective pressure might spill over into human infections, worsening the overall threat. According to the Union of Concerned Scientists, 70 percent of antibiotics used in this country are fed to healthy livestock; another 14 percent treat sick livestock. The remaining 16 percent go to people and pets. And about that time, newer molecular tracking techniques started indicating that indeed, some resistant strains of human pathogens were finding their way from feedlots and farms into hospitals and humans. As an old song asked, “How you gonna keep ‘em down on the farm?”
Apparently, we cannot. A 2002 Clinical Infectious Diseases meta-analysis of more than 500 studies found that “many lines of evidence link antibiotic resistant human infections to foodborne pathogens of animal origin.” The Institute of Medicine concluded in 2003, “Clearly, a decrease in the inappropriate use of antimicrobials in human medicine alone is not enough. Substantial efforts must be made to decrease inappropriate overuse in animals and agriculture as well.” In 2004, the World Health Organization reported that increasing resistance was linked to “nonhuman usage of antimicrobials.”
That’s a brief summary of expert opinion and evidence. In light of this, the European Union has banned the use of antibiotics in livestock except to treat illness—and the evidence grew stronger. The most intensively studied country, Denmark, saw a 50% decrease in total antibiotic use without negative impacts on farmers or consumers but a large public health benefit. But what about here in the USA?
Back in 2002, the San Francisco Medical Society convened a conference (co-sponsored by Commonweal) on this issue, co-chaired by two living legends of American medicine and public health, Philip Lee, MD, and Lester Breslow, MD. One result of that meeting was a policy resolution urging the phaseout of routine use of antibiotics in agriculture; this policy was adopted by the SFMS, CMA, and AMA. But, to be frank, not much has changed in practice.
The latest federal legislation introduced to stop the use of important human antibiotics in the feed and water of animals that are not sick is called PAMTA—the Preservation of Antibiotics for Medical Treatment Act (HR 1549/S.619). Hundreds of health, medical, and consumer and environmental groups have endorsed it. In a Congressional hearing, a former FDA Commissioner held that using antibiotics on healthy farm animals has to stop.
And what do farmers think? Many smaller producers, especially in the “organic”-type sector, already forego antibiotics unless absolutely necessary. But “big agriculture” lobbyists fight any restrictions. They have argued that restrictions in Europe have led to outbreaks and higher costs, but again, authorities there say that this is a “creative” and untrue rumor. And now even the USDA holds that the cost savings of using antibiotics is a mirage in most cases.
Once again, the sad precedent of the “tobacco wars” is conjured. The evidence of a severe health threat is strong; corrective measures are proposed and endorsed; political lobbying gridlocks the remedy. The risk keeps growing, and people suffer and die. PAMTA (Preservation of Antibiotics for Medical Treatment Act), at a minimum, needs to be enacted. Even more regulation is likely warranted. Will our leaders listen before uncontrollable disaster strikes?
Martin Blaser, MD, a past president of the Infectious Disease Society of America, warns of “lethal pandemics” if antibiotic resistance is not brought under control. In fact, some longtime observers of this threat fear that, rather than a nuclear or other threat, it might well be our smallest, longtime, invisible enemies that prove the end of humanity, coming “not with a bang, but with a whimper.”
For more information, see http://www. keepantibioticsworking.com
