For clean elective surgery, the goal of nosocomial infection control is nothing less than an infection rate of zero. Although infection rates of less than 1% are being posted regularly in selected surgical operations today, infection rates of 2% to 6% persist in many procedures such as coronary artery bypass surgery and vascular surgery. Predictable achievement of a zero infection rate in all of clean surgery will require new directions in both basic and clinical research.

Research into the prevention of infection in clean surgery has, to date, focused upon 1) identifying and controlling the routes of wound contamination, 2) decontamination of a contaminated wound through the prophylactic use of antimicrobials, and 3) modifying the host immune system. The latter is a fascinating area of new research which will not be discussed in detail here.

Routes of contamination are often categorized as endogenous or exogenous. “Endogenous” generally refers to bacterial seeding of the wound from the flora of the patient's own skin, nose, perineum, and GI tract. “Exogenous” contamination has come to mean bacteria originating from the operating room environment or operating room personnel which reach the wound by direct inoculation (eg, improperly sterilized instruments, hands of the surgeon via torn gloves) or by the airborne route. These categories may not be broad enough to satisfy the complexities of the hospital environment, however. The addition of the category “acquired endogenous” may be of help in describing contamination which occurs when patients become colonized with resistant hospital flora and subsequently carry this newly acquired flora into the operating theater.