Targeting drug-resistant infections

Last week, Chinese and British scientists reported finding a strain of E. coli resistant to a last-resort antibiotic called colistin — and that this resistance can be transferred to other bacteria. Harvard Chan School’s William Hanage, an infectious disease epidemiologist, discusses the growing problem of drug-resistant infections.

What is causing the increase in drug-resistant infections?

We’ve been using antibiotics inappropriately. These drugs don’t work against things like flu that are caused by viruses, and so you shouldn’t expect them if you go to see your doctor about those typical winter respiratory infections. Also, we should remember that enormous volumes of these drugs are used in agriculture, not only to keep animals healthy but as growth promoters to improve yields. Drug resistance is getting worse because every time we use an antibiotic, whether in humans or animals, we give an advantage to any bacteria that are resistant to it! So this means we have to be careful with how we use antibiotics, because they are precious.

What does the new discovery about colistin mean, and why is it worrying?

Colistin is one of the last lines of defense we have against drug-resistant infections. So if we can’t use colistin that means more people will die from infections, because we won’t be able to treat them.