Transfer and Decontamination of S. aureus in Transmission Routes Regarding Hands and Contact Surfaces.

Hand hygiene, cleaning and disinfection are pre-requirements for hygiene management in hospital settings and the food industry. In order to facilitate risk management, different contamination scenarios and interventions need to be evaluated. In the present study data on transfer rates and reductions of Staphylococcus aureus were provided in an experimental set-up using artificial skin. Using this methodology, test persons were not exposed with pathogenic bacteria. An exposure assessment model was developed and applied to evaluate different contamination routes and hygiene interventions. The transfer rates of S. aureus from inoculated VITRO-SKIN® to fomites were calculated from blotting series. The VITRO-SKIN® was more prone to spread bacteria than fomites. When different surfaces were cleaned, the reduction of S. aureus varied between <1 and 7 log CFU. It could not be concluded that a certain coupon material, cleaning agent, cleaning wipe, soiling or humidity consistently resulted in a high or low reduction of S. aureus. The reduction of S. aureus and E. coli during hand washing was evaluated on artificial skin, VITRO-SKIN®. The reduction of E. coli on VITRO-SKIN® was similar to the log reduction obtained when washing human hands. The S. aureus count on a human hand was both calculated in different scenarios describing different contamination routes starting from a contaminated hand using the exposure assessment model, and measured on an experimental setup using VITRO-SKIN® for validation. A linear relationship was obtained between the analysed level of S. aureus and the calculated level. However, the calculated levels of S. aureus on the VITRO-SKIN® in the scenarios were 1-1.5 log lower than the analysed level. One of the scenarios was used to study the effect of interventions like hand washing and cleaning of surfaces.

["Bacterial scouting" to reduce healthcare associated infections. New method can identify and address risk factors for disease transmission]. / Bakterie-spaning« för att minska vårdrelaterade infektioner - Ny metod kan identifiera och åtgärda riskfaktorer för smittspridning.

This is a report of a multidisciplinary project conducted at Karolinska University Hospital in Stockholm. The aim was to study and reduce potential risk factors for the spread of health-care associated infections in the near-patient environment. A process beginning with an observation study conducted by two observers of which one was an industrial designer or a psychologist was used. Bacterial screenings were used to verify factors identified during the observations. The main focus of activities to reduce the identified risks was mainly to improve the cleaning. Improved cleaning routines reduced the microbiological level significantly.