Antibiotic overuse: a key driver of antimicrobial resistance

The widespread use of antibiotics is estimated to have extended average life expectancy by two decades, shifting the paradigm from communicable to non-communicable diseases. Antimicrobials and antibiotics in particular have paved the way for major advances in cancer treatment, organ transplantation, and surgery, irrevocably changing the scope of modern medicine.

Every time a new antimicrobial is introduced, drug resistance to that antimicrobial follows, sometimes swiftly, and this occurs for antibiotics, antivirals, and antifungal therapies. Antimicrobial treatment places selective pressure on the organism, favouring the emergence of drug-resistant strains. This is not a new problem: antibiotic resistance emerged within a decade of the first clinical trials of penicillin, with more than 50% resistance among Staphylococcus aureus by the end of the 1940s. Until recently we have escaped the dire consequences of antimicrobial resistance because there has been a stream of new antibiotics. However, over the past 20 years the number of pharmaceutical companies investing in this area has dwindled from 18 to 4, inevitably leading to stalled drug development.

Antimicrobial resistance affects every country because infections do not respect international boundaries or borders. Each time a person travels they take their active infections and colonising bacteria with them, spreading drug-resistant organisms across the globe. Many countries overuse antibiotics, particularly in hospitals. Although hospital prescribing accounts for only 20% of human usage, it is important because it is concentrated, and because hospitals are fertile breeding grounds for drug-resistant bacteria. In animals and …