Surgical Site Infection

A surgical site infection (SSI) involves the incision, deeper soft tissue, or an organ or space opened or manipulated during an operation. Microbes can reach the wound from the patient's skin or mucosa, the operative field, personnel, equipment, or the environment. Infection develops when microbial burden and virulence overcome local tissue defences and the patient's immune response. Tissue injury, devitalized tissue, poor perfusion, foreign material, and impaired host defences can make clearance more difficult. Superficial incisional SSI is limited to skin and subcutaneous tissue. Deep incisional SSI involves fascia or muscle. Organ/space SSI involves tissue deeper than fascia or muscle in a body site opened or manipulated during the procedure. These depth labels describe anatomy; they do not assign a fixed probability to an individual patient. Colonization means microbes are present without tissue invasion or injury, whereas infection includes multiplication with a host response. An implanted device can provide a surface on which pathogens persist, so symptoms involving prosthetic material require careful assessment and timely review. Prevention therefore combines interruption of transmission with protection of perfusion and host defences. No...