Meticillin-resistant Staphylococcus aureus epidemiology and transmission in a Dutch hospital

The application of the search and destroy (S&D) policy in Scandinavian and Dutch hospitals is associated with low rates of meticillin-resistant Staphylococcus aureus (MRSA). The objective of our study was to describe the MRSA epidemiology and transmission in a Dutch hospital. This descriptive study was performed in a teaching hospital with approximately 40,000 admissions per year. In this hospital the MRSA S&D policy has been applied for several decades. MRSA epidemiology was studied during the years 2001 to 2006. The transmission rate in this hospital was determined using (1) patient's history, (2) relation in time and place to other patients or healthcare workers (HCWs), and (3) molecular typing (pulsed-field gel electrophoresis and Spa). Ninety-five persons were identified as MRSA carriers, namely 82 patients and 13 HCWs. The annual MRSA incidence increased more than three-fold during the study period, which was entirely caused by animal-related MRSA. Twenty-three percent of the patients acquired MRSA in a foreign hospital, 26% via animals, 16% by nosocomial transmission, 4% in another Dutch healthcare institution, 10% in the community via a known MRSA-positive person, and in 22% the source was unknown. For HCWs, 69% of MRSA was due to nosocomial transmission, 15% was related to working in a foreign hospital and in 15% HCWs became colonised via an MRSA-positive partner or relative. The transmission rate of 0.30 (22 secondary cases from 73 index cases) indicates that the spread of MRSA was under control during the study period, and so the S&D policy should be continued.