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

Abstract

Data supporting active surveillance of meticillin-resistant Staphylococcus aureus (MRSA) for the prevention of postoperative infection remain controversial. To investigate the efficacy of MRSA screening in patients undergoing gastroenterological surgery. 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). 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]. 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.