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.