During the past two decades, methicillin-resistant Staphylococcus aureus (MRSA) has become increasingly common as a source of nosocomial infections. Most studies of MRSA surveillance were performed during outbreaks, so that results are not applicable to settings in which MRSA is endemic.
Madeleine Dulon, of the Institution for Statutory Accident Insurance and Prevention in the Health and Welfare Services for the Department of Occupational Health Research in Hamburg, Germany, and colleagues, provide an overview of MRSA prevalence in hospitals and other healthcare institutions in non-outbreak situations in Western Europe.
A keyword search was conducted in the Medline database (2000 through June 2010). Titles and abstracts were screened to identify studies on MRSA prevalence in patients in non-outbreak situations in European healthcare facilities. Each study was assessed using seven quality criteria (outcome definition, time unit, target population, participants, observer bias, screening procedure, swabbing sites) and categorized as 'good', 'fair', or 'poor'.
The researchers report that 31 observational studies were included in the review. Four of the studies were of good quality. Surveillance screening of MRSA was performed in long-term care (11 studies) and acute care (20 studies). Prevalence rates varied over a wide range, from less than 1 percent to greater than 20 percent. Prevalence in the acute care and long-term care settings was comparable. The prevalence of MRSA was expressed in various ways - the percentage of MRSA among patients (range between 1 percent and 24 percent), the percentage of MRSA among S. aureus isolates (range between 5 percent and 54 percent), and as the prevalence density (range between 0.4 and 4 MRSA cases per 1,000 patient days). The screening policy differed with respect to time points (on admission or during hospital stay), selection criteria (all admissions or patients at high risk for MRSA) and anatomical sampling sites.
The researchers suggest that for comparisons between different healthcare settings, surveillance methods and outcome calculations should be standardized. Their results were published in BMC Infectious Diseases.
Reference: Dulon M, Haamann F, Peters C, Schablon A and Nienhaus A. MRSA prevalence in European healthcare settings: a review. BMC Infectious Diseases 2011, 11:138doi:10.1186/1471-2334-11-138