Objective: We assessed the rate of success of MRSA eradication therapies by using a strict treatment and follow up protocol and analysed determinants of eradication failure.
Methods: All MRSA positive patients of the Erasmus MC detected between January 2005 and December 2007 were followed up. Only patients, who were treated by or followed up by the Erasmus MC Rotterdam, were included in the study. Through medical chart review, possible risk factors for eradication failure at time of MRSA detection and at time of treatment, eradication regimens and microbiological culture results were collected. Treatment included mupirocine and chlorhexidine bodywash with or without two oral antibiotics for 10 days. Follow up was by 6 colonization cultures. Definition of MRSA negative was by showing 6 negative culture sets. SPSS 15.0 was used for statistical analysis.
Results: In 165 patients MRSA was detected, 55 patients were excluded (death, no treatment in our hospital, not eligible for treatment). If postponing of treatment was possible, patients were not treated unless indwelling devices were removed or non-intact skin, whatever reason, was not present anymore. By wait and see, 23 MRSA positive patients became MRSA negative decolonized over time without treatment. By the first antimicrobial treatment attempt 67,8% (n=59) of patients were successfully eradicated. After three eradication attempts an overall succesrate of 79,3% (n=69) was achieved. No significant determinants were discovered which could predict possible therapy failure. No differences in succesrates were found between different oral antimicrobial regimens. After 3 consecutive negative surveillance cultures, 29% of patients turned out to be MRSA positive again.
Conclusion: A standardised protocol can be highly effective in eradicating MRSA by antimicrobial therapy. More than 3 consecutive surveillance cultures are needed to reliable asses the MRSA negative status of a patient.