Value of pre- and postoperative meticillin-resistant Staphylococcus aureus screening in patients undergoing gastroenterological surgery.

BACKGROUND: Data supporting active surveillance of meticillin-resistant Staphylococcus aureus (MRSA) for the prevention of postoperative infection remain controversial. AIM: To investigate the efficacy of MRSA screening in patients undergoing gastroenterological surgery. METHOD: Nasal carriage of MRSA was screened using a polymerase chain reaction (PCR) assay on two gastroenterological surgery wards (A and B). Occurrence of postoperative MRSA infection was analysed according to nasal MRSA carriage status (pre-operative carriage and postoperative acquisition). FINDINGS: The incidence of pre-operative MRSA carriage was 9.7% on Ward A and 4.3% on Ward B (P = 0.009). Postoperative nasal MRSA acquisition was confirmed in 16.2% and 6.0% of patients, respectively (P < 0.001). There was no significant difference in the incidence of MRSA surgical site infections (SSIs) between patients with and without pre-operative nasal colonization on either ward. On Ward A, where MRSA nasal acquisition was more common, the MRSA infection rate in patients with postoperative nasal acquisition was 26.8%, which was significantly higher than the rates in patients with pre-operative MRSA colonization and patients without colonization during hospitalization. Postoperative nasal MRSA acquisition was an independent factor associated with MRSA infection on both wards [Ward A: odds ratio (OR) 7.192, 95% confidence interval (CI) 2.981-17.352; Ward B: OR 5.761, 95% CI 1.429-23.220]. CONCLUSION: MRSA SSIs were prevented by a screening-based strategy in pre-operative MRSA carriers. Postoperative nasal acquisition was a significant factor affecting MRSA infection, and the effect of screening varied according to the incidence of postoperative MRSA acquisition on the ward.