Antibiotics on the Farm: Agriculture’s Role in Drug Resistance

The discovery of antibiotics in the early 20th Century was a major breakthrough for human health, markedly reducing the infection threat from minor cuts, surgery, and cancer treatment. The more antibiotics are used, however, the faster bacteria adapt and become resistant to them. Antibiotic resistance is now spreading so rapidly, and the development of new antibiotics has slowed so much, that there is talk of a nightmarish post-antibiotic future where even minor injuries could once again become deadly if infection sets in. The threat is growing worldwide, but it is a particular problem in poor countries where respiratory infections and diarrheal diseases remain leading causes of death, especially among children. While the misuse of antibiotics in human health is a key factor in accelerating the emergence of drug resistance, farmers also use large amounts of antibiotics in livestock. Moreover, many administer these drugs in feed and water at low doses for extended periods to promote growth and prevent disease in their animals. Those are ideal conditions allowing drug resistant bacteria to thrive. Many industrialized countries are taking steps to address this risk, but there are often loopholes. And livestock production is growing rapidly in developing countries where antibiotic use is lightly regulated. Policymakers desperately need more information about antibiotic use and resistance in humans and animals so they can assess the risks of this behavior for human health, and determine how aggressive they need to be with policies to change it. At the same time, there is growing evidence that the economic benefit to livestock producers of using antibiotics may be less than thought. Given what is at stake in keeping antibiotics effective, it is prudent to couple improved data collection with steps to reduce the use of medically important antibiotics in farm animals.