Characteristics and outcomes of methicillin-resistant staphylococcus aureus surgical-site infections in patients with cancer: A case-control study

Background. Methicillin-resistant Staphylococcus aureus (MRSA) infections remain a significant cause of morbidity and mortality. We experienced an increased incidence of MRSA surgical-site infections (MRSA SSIs) at our institution. However, to our knowledge, no studies have evaluated the risk factors and outcomes of MRSA SSIs in cancer patients. Methods. We conducted a case-control study and identified all patients who had developed MRSA SSIs at our institution from July 1, 2002 to July 30, 2003, and all patients who had undergone surgery by the same surgical team during the same time period but who had not developed MRSA SSIs. Cases and controls were age-matched at 1:2 ratio. Results. The study included 29 cases and 58 controls. Mean interval between surgery and MRSA SSI onset was 17.8 days (range 3-75 days). Cases were more likely than controls to have progressive cancer (72 versus 38%), have received antibiotics (mainly quinolones) within 24 h of surgery (17 versus 2%), have had ongoing infection (10 versus 0%), and have had longer hospital and intensive care unit stays (11.0 versus 7.8 days and 3.4 versus 1.5 days) (all P<0.05). In a multivariate logistic regression analysis, significant predictors of MRSA SSI in cancer patients were antibiotics use <24 h of surgery and progressive cancer. No surgical factors (i.e., procedure time or timing of perioperative antibiotics) were associated with increased risk of MRSA SSI. Conclusions. Several clinical and postoperative factors were associated with increased risk of MRSA SSI in cancer patients, but antibiotic use before surgery (especially quinolones) and progressive cancer were the only independent predictors.