Staphylococcus aureus surgical site infection rates in 5 European countries

Objective To determine the overall and procedure-specific incidence of surgical site infections (SSI) caused by Staphylococcus aureus ( S. aureus ) as well as risk factors for such across all surgical disciplines in Europe. Methods This is a retrospective cohort of patients with surgical procedures performed at 14 European centres in 2016, with a nested case–control analysis. S. aureus SSI were identified by a semi-automated crossmatching bacteriological and electronic health record data. Within each surgical procedure, cases and controls were matched using optimal propensity score matching. Results A total of 764 of 178 902 patients had S. aureus SSI (0.4%), with 86.0% of these caused by methicillin susceptible and 14% by resistant pathogens. Mean S. aureus SSI incidence was similar for all surgical specialties, while varying by procedure. Conclusions This large procedure-independent study of S. aureus SSI proves a low overall infection rate of 0.4% in this cohort. It provides proof of principle for a semi-automated approach to utilize big data in epidemiological studies of healthcare-associated infections. Trials registration The study was registered at clinicaltrials.gov under NCT03353532 (11/2017).