The Impact of MRSA Colonization on Surgical Site Infection Following Major Gastrointestinal Surgery

Purpose: The purpose of this study is to determine whether methicillin-resistant Staphylococcus aureus (MRSA) colonization affects surgical site infections (SSI) after major gastrointestinal (GI) operations. Methods: We retrospectively reviewed the charts of all patients undergoing major GI surgery from December 2007 to August 2009. All patients were tested for MRSA colonization and grouped according to results (MRSA+, methicillin-sensitive S. aureus [MSSA]+, and negative). Data analyzed included demographics, incidence of SSI, and wound culture results. Results: A total of 1,137 patients were identified; 78. 9 % negative, 14. 7 % MSSA+, and 6. 4 % MRSA+. The mean age was 59. 5 years, 44. 5 % of the patients were men, and 47. 9 % of the patients underwent colorectal operation. SSI was identified in 101 (8. 9 %) patients and was higher in the MRSA+ group than the negative and MSSA+ groups (13. 7 vs. 9. 4 vs. 4. 2 %; p < 0. 05). Although MRSA colonization had an odds ratio of 1. 43 for developing an SSI, it was not a significant independent risk factor. However, the MRSA+ group was strongly associated with MRSA cultured from the wound when SSI was present (70 vs. 8. 5 %; p < 0. 0001). Conclusions: MRSA colonization is not an independent risk factor for SSI following major GI operations; however, it is strongly predictive of MRSA-associated SSI in these patients. Preoperative MRSA nasal swab test with decolonization may reduce the incidence of MRSA-associated SSI after major GI surgery.