The study never started due to administrative reasons.

Visible light at 405nm has been shown to be germicidal. The hypothesis is that use of this light (Indigo-Clean Lights) in operating rooms will reduce S. aureus transmission occurring within and between patients and reduce surgical site infections (SSIs). Investigators will evaluate a case-control study where patients undergoing surgery with the lights are matched with patients undergoing surgery without germicidal lights.

Operating room S. aureus exposure has been directly linked to postoperative infections and is therefore an important target for infection prevention. Visible light at 405nm has been shown to be germicidal. Investigators plan to install ambient, germicidal lighting (Indigo-Clean Lights) that uses this wavelength in 4 operating rooms. Patients will undergo surgery according to usual practice. Investigators will conduct a case-control study where patients undergoing surgery with the lights are matched with patients undergoing surgery without the germicidal lights. Patients will be matched by procedure then case duration then American Society of Anesthesiologists (ASA) physical status health classification. These patients will undergo infection surveillance. Infection surveillance will involve use of National Healthcare Safety Network (NHSN) checklists applied to patients who are positive for one or more of the initial screening criteria (elevated white blood cell count, fever (>38.4 degrees Celsius), office note documentation of infection, positive culture (sputum, blood, urine, wound, other body fluid), or anti-infective order within the 90 postoperative day period.

Inclusion Criteria:

• Adult, at least 18 years old
• Adult patients undergoing orthopedic, cardiothoracic, gyn/onc, and neuro surgery and general anesthesia according to usual care with peripheral and/or central venous access.

Exclusion Criteria:

• Pediatric (<18 years old),
• Incarcerated, and/or
• Pregnant patients
• Undergoing surgery and/or without peripheral or central venous access.
• Undergoing surgery outside of the classifications above

IPD related to the registered primary (S. aureus transmission dynamics) and secondary outcomes (healthcare-associated infections) will be shared freely with scientists who request them. The request process will require submission and review of a research proposal for data use by the PI (Loftus) and Indigo-Clean.

IPD will be available for sharing immediately after publication and ending 5 years following article publication.

IPD will be accessible to researchers who provide a methodologically sound proposal, to achieve aims in the approved proposal.