assessment and risk-based screening were first developed to identify risk factors for MRSA carriage, later questions to determine carriage of other MDRO were added. Recently, the efficacy of the MDRO universal risk assessment and risk-based screening is questioned (32). As timely identification and isolation of MDRO carriers is essential in preventing transmission throughout the hospital, improvement of the universal risk assessment should be considered. For instance, while in the universal risk assessment patients are asked if they have been hospitalized abroad, there is no question regarding recent travel history. Recently, literature has focused on the risk of HRMO acquisition during travelling, specifically to south-east Asia (33-35). However, the studies were performed with healthy travelers, and consequently cannot directly be extrapolated to patients admitted to our hospital. Besides improving the universal risk assessment and risk-based screening, other screening strategies should also be considered, such as a universal screening strategy. In order to generate further evidence for improving universal or risk-based risk assessment on colonization of HRMO, we performed two studies. In this thesis (chapter 2.2), we assess if colonization with MDRO following international travel among patients is high enough to include this as a risk factor in the risk assessment. In chapter 2.3 of this thesis, we aim to compare the yield of a universal screening strategy with the currently installed universal risk assessment and risk-based screening. Environmental contamination Surfaces in hospitals can act as reservoirs for pathogenic microorganisms, and hence for MDRO. The time period microorganisms are able to survive on surfaces differs per type of microorganism and can range from a few hours up to several months (36). Consequently, when a surface is not correctly cleaned and/or disinfected, the surface can be a lasting source for transmission. Studies determining the environmental contamination with MDRO in non-outbreak settings have showed contamination rates of up to 55%, even after terminal disinfection of the surface (37-40). Environmental sampling practices Environmental sampling can be performed for a number of reasons, but is mainly performed in outbreak situations to determine the source of the outbreak. Other reasons for environmental sampling could be evaluating cleaning/disinfection practices, routine sampling, or for research purposes. Environmental sampling methods can be divided into direct or indirect sampling methods. Direct sampling methods are methods that require no further processing, while extra processing is necessary for indirect methods (41). Examples of direct sampling methods are contact plates, dip slides and petriflm, examples of indirect sampling methods are sponges, wipes, and different types of swabs (e.g., cotton swabs, flocked swabs, rayon swabs). Swabs are most often used when performing sampling of the 1 15 General introduction
RkJQdWJsaXNoZXIy MTk4NDMw