Background Methicillin-Resistant Staphylococcus aureus (MRSA) is endemic in hospitals worldwide. When patients are transferred between wards within a hospital, their risk of acquiring MRSA may change. Studies investigating such association are rare. In this study, we assessed how wards are connected and investigated ward characteristics associated with MRSA acquisition. Methods We analysed electronic medical records from an acute-care tertiary hospital in Singapore using data of patient transfers and MRSA screening of hospitalized patients between 2010 and 2013. In multivariable analysis, we used mixed-effects Poisson models with wards and time as random intercept and random slope, respectively. Results Most patient transfers concentrated in a core network of wards that sustained over time. Overall MRSA acquisition rate declined over study period. Factors associated with MRSA acquisition were ward specialty other than surgical, orthopedics, and oncology (rate ratio (RR): 1.69, 95% CI: 1.28, 2.21) (compared to medical ward), MRSA admission prevalence (RR: 1.48, 95% CI: 1.28, 1.71, per one percentage point increase), presence of cohorting beds (RR: 1.81, 95% CI: 1.45, 2.27), critical-care ward (RR: 1.85, 95% CI: 1.21, 2.84) and average number of patients on a typical day (RR: 1.58, 95% CI: 1.24, 2.00, for every 10 patients quarterly). We did not find evidence that ward connectivity influenced MRSA acquisition rate after adjusting for other ward characteristics. Conclusion Our findings highlighted ward characteristics associated with MRSA acquisition. Linked with analytics infrastructure, similar methods could be used to understand the transmission of other nosocomial organisms to inform infection control efforts in real time.
medrxiv Subject Collection: Infectious Diseases