If the phrase “too much of a good thing” applies to anything, it surely applies to antibiotics. Their discovery was one of the most important medical advances of the last century, but overuse has eroded their effectiveness. There’s widespread agreement on the need to speed up development of new antibiotics and to discourage doctors from prescribing the drugs when they’re not needed. Another side of the issue is more contentious: roughly 80 percent of antibiotics in the U.S. are fed to farm animals. Regulators say using them to fatten livestock faster helps spread drug resistance. Meanwhile, globally an estimated 700,000 people a year die from drug-resistant infections, with millions more falling sick.
In late 2015, researchers reported the discovery of a freshly evolved gene capable of neutralizing the strongest antibiotic drugs. Apparently arising from the agricultural use of antibiotics in China, the gene uses a mechanism that will allow resistance to spread more quickly than ever. Under a U.S. Food and Drug Administration voluntary plan, all relevant drug companies have agreed to relabel antibiotics, making their use contingent on a veterinarian’s prescription. The state of California adopted an outright ban on giving the drugs to healthy animals in 2015. The European Union imposed one in 2006. Among the fast-food chains that have announced policies to reduce the use of meat from animals raised with antibiotics are Chipotle, Panera Bread and McDonald’s. Tyson Foods, the biggest seller of chicken in the U.S., announced it would eliminate the use in healthy birds of antibiotics that are also used by humans by September 2017. Health officials report some success in campaigns to limit inappropriate use by humans. One study concluded that while total global consumption of antibiotics grew by 36 percent between 2000 and 2010, use was stable or fell moderately in most wealthy countries. Most of the growth was in poorer nations, where antibiotics are often given as a substitute for public-health measures. On another front, the FDA is considering requiring companies to prove the effectiveness and safety of antibacterial hand washes, arguing that they don’t improve health and may be contributing to resistance.
Bacteria are constantly mutating, and some change in ways that let them survive a particular treatment. Repeated exposure leads to more of the resistant bacteria. The antibiotic era in animal agriculture began in 1946, when researchers noted that chickens fed low doses of the drugs grew faster. Antibiotics have become a crucial part of factory farming – animals in cramped conditions would be vulnerable to infections without daily doses of the drugs. For decades, the livestock and pharmaceutical industries successfully fended off regulation, arguing that little correlation could be drawn between antibiotics used in agriculture and resistant infections in humans. But evidence has mounted that resistant bacteria on farms reaches humans through soil, air or water contaminated with animal waste and through consumption of animal products. The increasing prevalence of counterfeit antibiotics certainly feeds resistance. Meanwhile, the number of large drug companies developing new antibiotics dropped to four in 2014 from 20 in the late 1990s.
The FDA says its voluntary relabeling strategy will reduce antibiotic use in livestock faster than a ban that would take years to push through. Industry groups such as the American Meat Institute applauded the voluntary approach. Some consumer advocates criticized the plan as a hollow gesture. Because farmers can still use antibiotics to prevent disease, meaningful change is unlikely, a 2013 study concluded. EU officials say they have seen some decline in the use of antibiotics since the 2006 ban, though the effect has been muted by higher rates of illness when herds aren’t taking them to promote growth. Denmark put a ban in place earlier and has seen a bigger drop — partly because farmers learned that they needed to raise their animals in healthier conditions once they weren’t getting a daily dose.
The Reference Shelf
- Reports on the crisis of and tackling antimicrobial resistance, commissioned by the U.K. Prime Minister.
- Reports on antibiotic resistance from the World Health Organization and the CDC.
- A U.K.-Swedish report on the threat antibiotic resistance poses to global health security.
- The Pew Charitable Trust’s report “Reviving the Pipeline of Life-Savings Antibiotics.”
- Statement by the Infectious Diseases Society of America on the 2012 GAIN Act, which added incentives for antibiotic development.
- A Bloomberg QuickTake on food safety.
First published March 13, 2014
To contact the editor responsible for this QuickTake:
Lisa Beyer at email@example.com