WHEN THE DRUGS DON’T WORK
Some people describe Darwinian evolution as “only a theory”. Try explaining that to the friends and relatives of the 700,000 people killed each year by drug-resistant infections.
Resistance to antimicrobial medicines, such as antibiotics and antimalarials, is caused by the survival of the fittest. Unfortunately, fit microbes mean unfit human beings. Drug-resistance is not only one of the clearest examples of evolution in action, it is also the one with the biggest immediate human cost. And it is getting worse. Stretching today’s trends out to 2050, the 700,000 deaths could reach 10m. Cynics might be forgiven for thinking that they have heard this argument before. People have fretted about resistance since antibiotics began being used in large quantities during the late 1940s.
Their conclusion that bacterial diseases might again become epidemic as a result has proved false and will remain so. That is because the decline of common 19thcentury infections such as tuberculosis and cholera was thanks to better housing, drains and clean water, not penicillin. The real danger is more subtle—but grave nonetheless. The fact that improvements in public health like those the Victorians pioneered should eventually drive down tuberculosis rates in India hardly makes up for the loss of 60,000 newborn children every year to drug-resistant infections. Wherever there is endemic infection, there is resistance to its treatment.
The spread of resistance is an example of the tragedy of the commons; the costs of what is being lost are not seen by the people who are responsible. You keep cattle? Add antibiotics to their feed to enhance growth. The cost in terms of increased resistance is borne by society as a whole. You have a sore throat? Take antibiotics in case it is bacterial. If it is viral, and hence untreatable by drugs, no harm done—except to someone else who later catches a resistant infection. The lack of an incentive to do the right thing is hard to correct. In some health-care systems, doctors are rewarded for writing prescriptions. Patients suffer no immediate harm when they neglect to complete drug courses after their symptoms have cleared up, leaving the most drug-resistant bugs alive. Because many people mistakenly believe that human beings, not bacteria, develop resistance, they do not realise that they are doing anything wrong.
Sugar the pill
Because antimicrobial resistance has no single solution, it must be fought on many fronts. Start with consumption. The use of antibiotics to accelerate growth in farm animals can be banned by agriculture ministries, as it has in the European Union. All the better if governments jointly agree to enforce such rules widely. In both people and animals, policy should be to vaccinate more so as to stop infections before they start. That should appeal to cashstrapped health systems, because prophylaxis is cheaper than treatment. By the same logic, hospitals and other breeding grounds for resistant bugs should prevent infections by practising better hygiene. Governments should educate the public about how antibiotics work and how they can help halt the spread of resistance. Such policies cannot reverse the tragedy of the commons, but they can make it a lot less tragic.
Patients suffer no immediate harm when they neglect to complete drug courses after their symptoms have cleared up, leaving the most drugresistant bugs alive.