Epidemiology of Methicillin-Resistant Staphylococcus aureus (MRSA) Bloodstream Infection: Secular Trends Over 19 Years at a University Hospital

摘要

Methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infection (BSI) is a cause of concern in health systems all over the world, due to the high incidence rates and the associated undesirable outcomes. In our tertiary 900-bed university hospital, all episodes of MRSA-BSI have been prospectively followed up since the identification of the first episode in 1990. We conducted the current study to report changes in the epidemiology of MRSA-BSI over the 19-year period between 1990 and 2008, comparing 4 periods (1990-1994, 1995-1999, 2000-2004, and 2005-2008). Overall, 524 patients developed MRSA-BSI. Cumulative incidence was 10.0 episodes/100,000 patient days (range, 1.3-17.4). Although no trend in the incidence rate was observed between the 4 consecutive periods, significant upward trends in patient age and comorbidities, health care acquisition, and non-intravascular catheter source were all identified (p In conclusion, we identified significant changes in demographic and clinical characteristics and in the molecular epidemiology of MRSA-BSI during the study period, but found no significant trends in cumulative incidence or in overall mortality rate. Abbreviations: BSI = bloodstream infection, CLSI = Clinical and Laboratory Standards Institute, EARSS = European Antimicrobial Resistance Surveillance System, hVISA = heterogeneous vancomycin-intermediate Staphylococcus aureus, ICU = intensive care unit, MIC = minimum inhibitory concentration, MRSA = methicillin-resistant Staphylococcus aureus, MSSA = methicillin-susceptible Staphylococcus aureus, NCCLS = National Committee for Clinical Laboratory Standards, PFGE = pulsed-field gel electrophoresis, RP = resistance pattern, SCCmec = staphylococcal cassette chromosome mec, ST = multilocus sequence typing.