Objective: To determine the incidence and prevalence of carriage of methicillin-resistent Staphylococcus aureus (MRSA) in patients and hospital personnel, and to examine the consequences of the revised Dutch MRSA guideline with respect to patients who have frequent contact with pigs or calves (in the course of their work).
Design: Retrospective and prospective observational study using questionnaires.
Method: Since July 2006 patients who have contact with living pigs or calves have been regarded as a high-risk group for MRSA carriage, after it was established that this occupational group had an increased chance of carriage of the so-called non-typable MRSA (NT-MRSA). An inventory was made of incidence and prevalence of MRSA carriage in patients and hospital personnel, and of the consequences of the new MRSA policy, for the period July-December 2006.
Results: Information was obtained from 58 Dutch hospitals. On January 1 2007, 37 (64%) hospitals had changed their MRSA policy; 22% of the hospitals it was applied in accordance with the MRSA guideline. The new guideline resulted in an increase of MRSA screenings by 15% and of detected MRSA carriers by 44%. 73% of all MRSA screenings took place in the out-patients department. In regions with high pig-density the incidence of NT-MRSA was 12% in patients with risk factors for carriage. In 49% of the hospitals one or more NT-MRSA carriers were detected (range 1-19 carriers). Possible transmission of NT-MRSA in hospital was shown in 3 of 1,007 (0.3%) hospital personnel, but in none of the 183 fellow-patients, examined. In the same period transmission of typable MRSA was demonstrated in 41 of 2,019 (2.0%) patients and 33 of 5,190 (0.6%) of hospital personnel examined. Prevalence of NT-MRSA carriage in 6,197 screened hospital personnel was 0.05% (n = 3).
Conclusion: The revised Dutch MRSA guideline lead to an increase in the number of MRSA screenings by 15%, particularly in the out-patients department, and to an increase in the number of detected MRSA carriers by 44%. During 306 months of observation no patient-to-patient transmission ofNT-MRSA was demonstrated.