Around the world, antibiotics are being misused in livestock production, which is leading to an uptick in antibiotic resistance in humans. To stem the global threat, the world needs a new multilateral treaty that incentivizes farmers to scale back their prophylactic use of antimicrobial drugs. SAN DIEGO – Most of us are oblivious to the threats caused by our actions when those threats are invisible. Our use of antibiotics is a case in point. When used judiciously, antibiotics save lives and prevent the transmission of deadly diseases. But the therapeutic power of antibiotics is being squandered by their imprudent use in agriculture. Jonathan Anomaly Today, more than half of the antibiotics administered around the world are used in the production of food. Farmers use antimicrobials to treat infections in their livestock. The problem is that they commonly misuse antibiotics either to compensate for poor agricultural practices – such as overcrowding on factory farms, which encourages the spread of disease – or to accelerate growth and reduce production costs. These practices may appear harmless in isolation, but their aggregate effect is dangerous. As antibiotics enter the environment through the food people eat or the waste animals produce, antimicrobial resistance intensifies. And this affects human health in troubling ways. Every day, at hospitals and clinics around the world, patients are given antibiotics for bacterial infections like tuberculosis, gonorrhea, or pneumonia. Others receive antibiotics prophylactically, to prevent bacterial infections during surgery, or when underlying conditions or treatments (such as chemotherapy) compromise their immunity. Unfortunately, many widely used antibiotics are losing their ability to protect patients and treat disease; routine misuse of antibiotics in farming is a key reason why. Not long after the Scottish microbiologist Alexander Fleming discovered a fungus that could kill bacteria, he recognized that overuse of antibiotics would encourage resistance. As he warned in 1945, “the thoughtless person playing with penicillin is morally responsible for the death of the man who finally succumbs to infection with the penicillin-resistant organism.” Widespread misuse of antibiotics in agriculture is one of the most egregious forms of “playing with penicillin.” In 2015, a new antibiotic-resistant bacterium was discovered in Chinese pigs, and then in Chinese patients. Since then, two more variants of the bacterium have been discovered, and the genes that enable these bacteria to resist antibiotics and jump between species – so-called “mobile genetic elements” – have been found on farms and in hospitals around the world. If the reckless use of antibiotics in agriculture continues, the impact on people will be severe. Fortunately, there is a solution. More than a decade ago, the European Union banned antibiotics in agriculture for any purpose other than treating infections. And, although the rule is not perfect, it has helped lower antibiotic use. In Denmark, for example, total antibiotic use by pig farmers has decreased, despite a slight increase in antibiotics administered for treating porcine diseases. These gains, however modest, are encouraging – and should encourage further – coordinated action. Because of the global nature of the threat, only multilateral cooperation – in the form of a new treaty or trade agreements – can ensure that farmers everywhere abide by minimal standards for raising livestock without the unnecessary use of antibiotics. In December 2015, a study commissioned by the British government and chaired by the economist Jim O’Neill found that the most effective means of changing behaviors would be to cap the use of antibiotics, but allow individual countries to experiment with taxes or restrictions to meet the cap. Moreover, as I have argued elsewhere, farmers should be required to obtain a prescription before administering medicine to livestock. Although the EU’s ban includes such a provision, waivers and exemptions have watered down the rule. If a global consensus were reached – for example, through the G20 or the United Nations General Assembly – countries choosing to tax agricultural antibiotics could use the revenue to help ease the transition to alternative farming practices. Money could also go to fund research on in vitro meat, which would dramatically reduce animal suffering and lower the burden of infectious diseases. Most important, any new treaty must provide signatories with flexibility to meet the diverse needs of their farmers. The goal of global action should be to incentivize farmers to reduce their antibiotic use, not to mete out punishment. It is possible to create conditions under which antibiotics are used only to treat sick patients, not healthy animals. Although the world is a long way from that goal, consumer-driven practices in the United States and regulations in Europe have demonstrated that farmers will change their approach if encouraged or required to do so. Still, most of us remain blind to the unintended consequences of our decisions. Unless people voluntarily refrain from consuming factory-farmed meat, we will need governments and multilateral organizations to keep us on the right path. The writer is a professor of philosophy at the University of San Diego. Copyright: Project Syndicate