Bad Bugs, From Farm to Us: Curtailing Antibiotic Overuse in Agriculture September 4, 2012 Public Health, San Francisco Medicine, SFMS Member Lester Breslow, Philip Lee, Antibiotic overuse 0 By Steve Heilig, MPH; Philip R. Lee, MD; and Lester Breslow, MD Editor’s Note: With ever-increasing microbial resistance to our ever-challenged arsenal of antibiotics, clearly we need to do everything possible to stay ahead in the Darwinian race between bacterial pathogens and humanity. One intervention, increasingly indicated by research and supported by many reputable health organizations, is to decrease the massive prophylactic and growth-promoting use of antibiotics in the production of food, primarily meat. Ten years ago, the SFMS brought policy to the CMA and then to the AMA urging more careful and curtailed use of antibiotics in food production. We also hosted a daylong invitational conference on this topic, cochaired by two living legends of public health, Phil Lee, MD (a longtime SFMS member, UCSF chancellor emeritus, Stanford medical professor, and former United States Assistant Secretary of Health), and Lester Breslow, MD (dean emeritus of the UCLA School of Public Health, former California state health director, and past-president of the American Public Health Association), along with then-SFMS President George Susens, MD. This meeting resulted in a new network of advocates working to preserve antibiotics, as well as an editorial in the Western Journal of Medicine (then edited by SFMS member Linda Clever, MD). This piece, reprinted below, has become one of the most-cited articles on this topic, no doubt due to the stature of Lee and Breslow. Breslow died in April of this year at age 97, prompting extensive tributes, from the New York Times to many professional forums. Breslow said he saw himself as “a political activist for disadvantaged people”—which, with respect to microbes, could include anybody. This reprint is offered as one more thanks—and, sadly, it remains all too relevant. Click here for the list of references used in this article. Antibiotics are arguably the single most important and widely used medical intervention of our era. Almost every medical specialty uses antibiotic therapy at some point. These drugs have prevented incalculable suffering and death and are perhaps still the closest medications we have to a “magic bullet.” Of course, bad bugs can bite back, and bacterial adaptation and resistance were reported soon after antibiotics were first used. The struggle to stay one step ahead of pathogens has been widely described and debated. Correcting the overuse of antibiotics in human medicine has gradually become a priority, with slow but heartening progress being gained in this Darwinian race. Still, the rise of multidrug resistance and the ready transfer of resistant traits among pathogens require heightened action if we are to prevent increasing outbreaks of infections that become more difficult, or even impossible, to treat. One essential course of action is to minimize any and all causes and reservoirs of antibiotic resistance. Besides medical use in humans, there is the troubling issue of use in agriculture, specifically in livestock production. Antibiotics have long been routinely used not only for the treatment of infections but also as a means of getting animals to market faster by growth promotion. Controversies about these practices have resulted in numerous reports, dating back decades, urging more caution or outright bans on the practice. The World Health Organization and other leading medical and public health bodies have advised that animals not be dosed with antibiotics used in humans—to little avail here in the United States to date, even though our own Food and Drug Administration took this position as far back as 1972.1 Still, many longtime observers of the issue were surprised—or even shocked—to learn the true extent of antibiotic use on farms; estimates are that upward of 70 percent of all antibiotics manufactured are used in agricultural settings.2 Although the exact percentages are uncertain, agricultural antibiotic use is apparently more substantial than previously thought. And the type of use is worrisome because it involves continual, subtherapeutic doses that would seem to provide ideal environments for the selection of resistant pathogens. The introduction of new molecular epidemiologic tools has heightened the worry because these tools have been used to show that resistant bacteria originating on farms are finding their way into humans.3-10 The extent of this epidemiologic “spillover” to date is uncertain—assertions of the extent of bacterial resistance arising from farms vary widely—and this needs to be a higher research priority. But there is no question that the phenomenon does exist. Recognizing this risk, the American Medical Association’s House of Delegates adopted a policy that “nontherapeutic use of antimicrobials in animals that are also used in humans should be terminated or phased out based on scientifically sound risk assessments.”11 Reaction from the pharmaceutical industry, in the guise of a trade association of manufacturers of animal drugs, was swift. The Animal Health Institute erroneously claimed “The assertion that there is increasing evidence that resistance developed in animals is spreading to humans is not true,” and it went on to oppose any further restriction on agricultural use.12 As a case study of such profit-motivated opposition, Bayer Corporation vigorously contested the FDA’s proposal to withdraw a widely used class of antimicrobial, fluoroquinolones, from agricultural use. These medications are used to combat some of the same bacterial pathogens that are treated with the same drugs in human medicine. Hence, there is a high risk of resistant strains finding their way from animals to humans.13 Abbot Laboratories, the other major manufacturer of fluoroquinolones, showed admirable scientific judgment and corporate responsibility in agreeing to the FDA’s request. Unfortunately, judging from the Animal Health Institute’s response to the AMA, we fear the drug industry’s reactions may more closely mirror Bayer’s shortsighted approach. But notably, even some forward-thinking agricultural leaders are now questioning the wisdom of such stonewalling.14 Admittedly, we tend to give more credibility to those who do not have any financial interest in the status quo. Leading experts unequivocally state that our current practices of feeding antibiotics to animals go against “a strong scientific consensus that it is a bad idea” and that the long stalemate on this issue constitutes a “struggle between strong science and bad politics.”15 The intentional obfuscation of the issue by those with profit in mind is an uncomfortable reminder of the long and ongoing battle to regulate the tobacco industry, with similar dismaying exercises in political and public relations lobbying and even scandal.16 As with tobacco control, science and health concerns should take precedence over profit in regulating the overuse of antibiotics in the production of meat and other agricultural products. Antibiotics do have a place on farms, but the benefits of their use can likely be preserved while minimizing harm. We need to learn more about the extent of risk, but the delay tactic of allowing current practices to continue while “more research” is conducted is unacceptable. Enough is already known to justify a more cautious, preventive approach.17 Other nations are ahead of the United States in this regard and have banned routine agricultural use, with demonstrable benefit in reduced bacterial resistance.18 We call on the FDA or legislators to, in the coming year, ban the nontherapeutic agricultural use of antibiotics. This ban should be lifted only if it is scientifically proved, in unbiased studies, that this use does not contribute to bacterial resistance in humans. Producers of agricultural antibiotics should be required to submit data on the specific antibiotics used, in sufficient detail to track usage and resistance trends. Finally, individual and business consumers of meat should begin to demand that the meat they purchase be grown without the routine use of antibiotics. The need to preserve the efficacy and supply of our antibiotic tools becomes even more crucial. It is time for our government to act in the public interest on this important issue. Click here for information on the growing campaign surrounding this issue, including the AMA-endorsed Preservation of Antibiotics for Medical Treatment Act (PAMTA, H.R. 965/S. 1211). For a recent update on how Denmark is leading on this issue, see Pig out: If farmers do not rein in the use of antibiotics for livestock, people will be severely affected. Nature 486, 440. 28 June 2012. Originally published: West J Med. 2002 January; 176(1):9–11. References 1. World Health Organization. WHO acts to safeguard vital treatments for the future. WHO/39 September 11, 2001. www.who.int/inf-pr-2001/en/pr2001-39.html. 2. Mellon M, Fondriest S, Union of Concerned Scientists. Hogging it: Estimates of animal abuse in livestock. UCS Nucleus. 2001; 23:1-3. 3. Witte W. Medical consequences of antibiotic use in agriculture. Science. 1998; 279:996-997. 4. Ferber D. Superbugs on the hoof? Science. 2000; 288:792-794. 5. Alliance for the Prudent Use of Antibiotics, Tufts University. Annotated Ecology References. www.healthsci.tufts.edu/apua/Ecology/EcoFaq.html. 6. van den Bogaard AE, London N, Driessen C, Stobberingh EE. Antibiotic resistance of faecal Escherichia coli in poultry, poultry farmers and poultry slaughterers. J Antimicrob Chemother. 2001; 47:763-771. 7. Van Looveren M, Daube G, De Zutter L et al. Antimicrobial susceptibilities of Campylobacter strains isolated from food animals in Belgium. J Antimicrob Chemother. 2001; 48:235-240. 8. White DG, Zhao S, Sudler R et al. The isolation of antibiotic-resistant salmonella from retail ground meats. N Engl J Med. 2001; 345:1147-1154. 9. McDonald LC, Rossiter S, Mackinson C et al. Quinupristin-dalfopristin-resistant Enterococcus faecium on chicken and in human stool specimens. N Engl J Med. 2001; 345:1155-1160. 10. Sorensen TL, Blom M, Monnet DL, Frimodt-Moller N, Poulsen RL, Espersen F. Transient intestinal carriage after ingestion of antibiotic-resistant Enterococcus faecium from chicken and pork. N Engl J Med. 2001; 345:1161-1166. 11. American Medical Association. Antimicrobial Use and Resistance. House of Delegates resolution 508 (A-01), June 2001. www.keepantibioticsworking.com/library/uploadedfiles/American_Medical_Association_Resolution_508_-_.htm. 12. Animal Health Institute. Statement on AMA Resolution on Animal Antibiotics. June 20, 2001.http://www.ahi.org/News Room/Press Release/2001/June/ama.htm. 13. Olsen SJ, DeBess EE, McGivern TE et al. A nosocomial outbreak of fluoroquinolone-resistant salmonella infection. N Engl J Med. 2001; 344:1572-1579. 14. Richardson L. Animal agriculture's BSOD. California Farmer. 2001; 284:6. 15. Falkow S, Kennedy D. Antibiotics, animals, and people—again! Science. 2001; 291:397. 16. Marshall E. Scientists quit antibiotics panel at CAST. Science. 1979; 203:732-733. 17. Kriebel D, Tickner J. Reenergizing public health through precaution. Am J Public Health. 2001; 91:1351-1355. 18. Aarestrup FM, Seyfarth AM, Emborg HD, Pedersen K, Hendriksen RS, Bager F. Effect of abolishment of the use of antimicrobial agents for growth promotion on occurrence of antimicrobial resistance in fecal enterococci from food animals in Denmark. Antimicrob Agents Chemother. 2001; 45:2054-2059. Comments are closed.
