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 19th-century 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. This is true in the rich world, too. Drug-resistant versions of organisms such as Staphylococcus aureus are increasing the risk of post-operative infection. The day could come when elective surgery is unwise and organ transplants, which stop rejection with immunosuppression, are downright dangerous. Imagine that everyone in the tropics was vulnerable once again to malaria and that every pin prick could lead to a fatal infection. It is old diseases, not new ones, that need to be feared.
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.
Learn more: When the drugs don’t work