Assessment of the role of handwash basins in the airborne transmission of multi-drug-resistant organisms in clinical and non-clinical settings.

backgroundWhile transmission of multi-drug-resistant organisms (MDROs) in clinical settings is traditionally attributed to contact with contaminated surfaces and medical devices, growing evidence suggests that other elements of the hospital environment, particularly handwash basins, may also act as reservoirs of MDROs. However, the airborne transmission of MDROs from handwash basins under real-world conditions remains poorly characterized.

methodsAerosol and surface sampling were conducted in five inpatient hospital rooms and three non-clinical restrooms during faucet operation and under control conditions. Aerosols were collected using a single-stage Andersen Cascade Impactor and a BioSpot-VIVAS sampler. Drain swab samples were also collected. All samples were cultured on selective and non-selective media, and isolates were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, with a focus on carbapenem-resistant bacteria and Candida species.

resultsWe detected at least seven MDROs in aerosol samples during faucet operation in inpatient rooms and restrooms. Types of microbes differed substantially between the two aerosol sampling methods. An overlap of organisms was detected in aerosol and drain swab samples in several rooms.

conclusionsHandwash basin operation can contribute to the aerosolization of viable MDROs, highlighting a potential pathway that necessitates consideration in infection prevention strategies. Moreover, it is necessary to consider multiple aerosol collection methods for a comprehensive assessment of airborne pathogens.