Abstract and Introduction
At the dawn of the antibiotic era, the danger of creating resistant bacteria was already clear. "The time may come when penicillin can be bought by anyone in the shops," warned Alexander Fleming while accepting his Nobel Prize for the drug's discovery. "Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to nonlethal quantities of the drug make them resistant."
Toward the end of Fleming's life, in the 1950s, farmers discovered that feeding low doses of antibiotics to their livestock caused the animals to gain weight faster. Nobody knows for sure why or how this worked, but the amount of antibiotics used for livestock today is believed to dwarf the amount used in human medicine.
Widespread, indiscriminate use of these drugs is having the impact Fleming predicted. The World Health Organization has named resistance to antimicrobial agents one of the most significant global threats to public health. In the United States alone, antibiotic-resistant pathogens are conservatively estimated to cause at least 2 million infections and 23,000 deaths each year.
However, one country—Denmark—is leading the way in reversing this trend. Over the past two decades the country has instituted reforms to antibiotic use for livestock that are showing solid progress in reducing the prevalence of resistant bacteria.