Prevalence of methicillin-resistant Staphylococcus aureus in elective surgical patients at a public teaching hospital: an analysis of 1039 patients.

Methicillin-resistant Staphylococcus aureus (MRSA) is an increasingly common cause of postoperative surgical site infections (SSIs). It is unclear, however, whether asymptomatic colonization or nosocomial acquisition of MRSA results in postoperative SSI. We conducted a retrospective review of patients screened for MRSA between May 2008 and October 2010 at our institution. End points included rates of MRSA infection, SSI, and the cost of routine MRSA screening of patients undergoing elective surgery. Of the 1039 patients screened preoperatively, 48 (4.6%) tested positive for MRSA by nasal or oral swab, whereas 991 (95.4%) tested negative. Forty-five (93.8%) MRSA-positive patients received vancomycin or linezolid and three (6.25%) received cefazolin perioperatively. Three (6.25%) MRSA-positive patients developed postoperative SSIs. Two required rehospitalization for intravenous antimicrobials, whereas a third patient required removal of infected abdominal mesh. Twenty (2.02%) MRSA-negative patients and four (5.26%) unscreened patients developed non-MRSA SSIs. Regardless of MRSA status, none of 609 patients who had a laparoscopic procedure or inguinal hernia repair developed SSI. Twenty-two patients needed to be screened to obtain one positive test. The role of MRSA screening and longer perioperative coverage for MRSA-positive patients undergoing complex elective procedures remains to be determined.