The primary objective of ASPIRE-SSI is to determine the incidence of S. aureus infections, particularly S. aureus SSIs, in various adult surgical patient populations, and to identify the patient-related, pathogen-related, and contextual risk factors for the development of S. aureus SSI. Using this information, a SSI prediction tool will be derived for future clinical trials and public health interventions aimed at SSI prevention. Furthermore, immunologic features protective against S. aureus SSI will also be assessed.