When Alexander Fleming discovered penicillin in 1928, he ushered in a new era of medicine: the age of antibiotics. Infections that had once been fatal could now be treated with relatively simple cures. In the decades that followed, penicillin became just one of many antimicrobial drugs that enabled humans and animals to live longer, more productive lives. The proliferation of those drugs seemed to have few, if any, downsides.
But over the years, we have gotten into the habit of overusing and misusing antimicrobial medicines. Studies have shown that roughly one-third of U.S. antibiotic prescriptions are unnecessary. Approximately the same share of antibiotics consumed in Southern and Eastern Europe are taken without a prescription. At the same time, nearly two-thirds of the antimicrobial drugs used in Africa are considered substandard, thanks in large part to the sale of counterfeit medications. Each of these issues, along with drug precursors and untreated medical waste disposal, can help diseases become resistant more quickly than they otherwise would.
Despite the attention that has been paid to humans' reliance on antibiotics, the agricultural industry's use of the drugs may be more important to tamp down on in any campaign against drug resistance. By volume, 70 percent of the antibiotics approved for use in humans in the United States are used to treat livestock. And it is easy to see why: Studies show that a reduction in animal illness corresponds to a decline in human illness as well. The use of antimicrobial drugs in livestock can also promote animal growth and prevent or treat outbreaks among herds and flocks. For producers who are struggling to meet rising global demand for meat and poultry, boosting output is of chief concern.
Though it is impossible to pinpoint exactly how much the agricultural sector contributes to the mounting resistance to antimicrobial drugs, the gains in production it makes from antimicrobial use must be balanced against any risk it creates. But the short-term losses in output that producers might experience if they abandoned antibiotics make it unlikely that the sector will change much of its own volition. A substantial shift would probably come only in response to a massive change in policy — something that, given the power of the agricultural sector in many countries, seems fairly unlikely.
