Sanitation, antibiotics, and the end of the antibiotic era.

A decade after the publication of the highly influential O'Neill report, Tackling Drug-Resistant Infections Globally, antimicrobial resistance (AMR) continues to accelerate at an unprecedented rate. Despite being a cornerstone of global AMR strategies, antimicrobial stewardship has failed to reverse this trend. This failure reflects a fundamental misunderstanding of AMR as primarily a behavioural or prescribing problem, rather than an environmental one. A major driver of AMR is environmental pollution arising from the large-scale manufacture, release, and accumulation of antimicrobial substances that profoundly disrupt microbial ecosystems. While regulatory attention has focused on antibiotic contamination of local rivers during pharmaceutical manufacturing, this represents only a small fraction of the antibiotics produced and consumed globally. Following administration, and depending on the compound, up to 90% of biologically active antibiotic may be excreted unchanged and subsequently enter healthcare wastewater systems. Healthcare wastewater systems therefore function as a superhighway for the generation, amplification, and transmission of multidrug-resistant organisms-both within healthcare facilities and into surrounding municipal infrastructure. Traditional hospital defences, including Standard Infection Control Precautions, offer limited protection against pathogens originating from wastewater environments. Within these systems, high microbial biomass is continuously exposed to complex mixtures of antimicrobials, disinfectants, and other selective agents, distorting microbial ecology and creating conditions conducive to the selection of AMR. Recognising the healthcare wastewater system as a critical driver of AMR generation and dissemination reframes the problem and opens new opportunities for intervention. Addressing this overlooked reservoir may be essential to containing a global pandemic that, despite decades of effort, shows no sign of slowing.