Hospital sinks and healthcare-associated infection: ecology, transmission, surveillance and mitigation.

Hospital sinks are recognised polymicrobial reservoirs for multi-drug resistant organisms and have been implicated in patient transmission and outbreaks. Earlier studies on sink-associated microbes predominantly focused on specific species or resistance mechanisms (e.g. carbapenemases) using targeted microbiological methods. More recently, less selective approaches (e.g. metagenomic sequencing) have enabled broader characterisation of these microbial communities. This review summarises current evidence describing hospital sink-trap microbiomes, examining ecological determinants, surveillance strategies and interventions aiming to mitigate transmission from these reservoirs. We discuss biotic and abiotic factors that shape microbial selection/persistence, assess approaches to managing these reservoirs to reduce patient risk, and highlight priorities for future research to inform evidence-based practice in healthcare settings.