Droplet rather than Aerosol Mediated Dispersion is the Primary Mechanism of Bacterial transmission from Contaminated Hand Washing Sink Traps

Abstract

20An alarming rise in hospital outbreaks implicating hand-washing sinks has led to widespread 21 acknowledgement that sinks are a major reservoir of antibiotic resistant pathogens in patient-care

Carbapenem-resistant Enterobacteriaceae dispersal from sinks is linked to drain position and drainage rates in a laboratory model system

“…The results suggest that dispersal is largely droplet mediated and that splashes are multidirectional. This has been recently observed by others [25] and implies that the use of settle plates alone can provide a good indication of spread and range of dispersal.…”

“…Nonetheless, the use of a novel model system incorporating naturally contaminated waste traps taken from a hospital has provided a more realistic representation of the healthcare environment. This work and that of others [23,25] is proving that the use of laboratory model systems can produce valuable data to be considered when designing and testing infection prevention and control guidelines regarding sink management.…”

“…In this study, a laboratory model system incorporating artificially and naturally contaminated waste traps was used to investigate dispersal of CRE from sinks, with particular focus on the position of the drain in relation to the tap and drainage rate. Active air samplers have been previously used to detect Gram-negative organisms in aerosols released from the drain during flushing [9,25]. In the current study, the use of a cyclone sampler was combined with settle plates to assess dispersal from artificially contaminated waste traps.…”

The role of hospital environment in transmissions of multidrug-resistant gram-negative organisms

“…Sink basin design, water drainage speed, and connectivity of the plumbing system may potentially influence the occurrence and trajectory of MDRGN outbreaks [30][31][32]. In an experimental design, replicate handwashing sinks were inoculated with a green fluorescent protein (GFP)-expressing E. coli and dispersal was measured using settle plates and air sampling [30].…”

“…However, when a biofilm was allowed to develop, the sink strainer became colonized with GFP expressing E. coli. Subsequently, environmental contamination during faucet use occurred as a result of droplet dispersion [30,31]. Likewise, when the sink bowl was already contaminated, the use of the sink resulted in environmental contamination [30].…”