During the next 12 months, the CDC estimates that at least 2 million illnesses and 23,000 deaths will be caused by bacterial or fungal infections that no longer respond to antibiotics. And this problem, unfortunately, is getting worse, not better: Across the globe, 700,000 now die each year from such drug-resistant microbes; by 2050, according to a formidable blue-ribbon study commissioned by the UK government, that figure could well soar to 10 million, surpassing even worldwide deaths from cancer.
Antimicrobial resistance—or the rise of “Superbugs,” as the tabloids call it—is “one of the most serious threats to global health and security,” the World Health Organization warns. And make no mistake: the threat is also, largely, human-made.
Before I get to our culpability on this front, let’s start with nature’s. The problem, in a nutshell, is the superfast division speed of most bacteria, which leads inevitably to a revved up process of evolution. Under the right circumstances, a single E. coli bacterium, for instance, can divide into a 2,097,152–strong colony in a mere seven hours—and with each division comes the potential for mutation and adaptation, particularly if these organisms are exposed to strong selective pressures.
That’s where we come in. We mortals help push that fast evolutionary process into warp speed in at least two ways. First, we do it through our long practice of overprescribing and inappropriately prescribing antibiotics to patients. These ineffective treatments often leave in their wake surviving microbes that develop resistance to the drugs used and then pass along those adaptations to subsequent generations. As the saying goes: “Whatever doesn’t kill you, makes you stronger.” (To see how feverishly fast resistant strains can emerge, see this scary timeline.)
Secondly, we egg on evolution through another insidious process: routinely giving sub-therapeutic antibiotics to livestock—something that the agriculture industry has been doing for nearly eight decades, or since the age of antibiotics began in the 1940s.
How we came to do this is a twisting tale that science writer Maryn McKenna elegantly unspools in her extraordinary new book, Big Chicken: The Incredible Story of How Antibiotics Created Modern Agriculture and Changed the Way the World Eats, which was published in September. Here’s a link to this must-read. (And in case you missed clicking on that link, here’s another.)
“At this moment, most meat animals, across most of the planet, are raised with the assistance of doses of antibiotics on most days of their lives: 63,151 tons of antibiotics per year,” McKenna writes. Farmers began to use the drugs when they discovered that it helped “convert feed to tasty muscle more efficiently.” The drugs, which could be administered in both feed and water, helped shield the livestock from disease, which also allowed farmers to pack more animals into barns and transformed old-fashioned agriculture into its modern industrialized form.
Once resistant bacteria are in the gut of an animal, then one of several things happens, McKenna says: When the animal is taken to the slaughterhouse, the mutated microbes in their digestive tracts can sometimes “get splashed on the meat.” And then, those resistant bacteria on the…