Routes and Sources ofStaphylococcus aureusTransmitted to the Surgical Wound During Cardiothoracic Surgery Possibility of Preventing Wound Contamination by Use of Special Scrub Suits

Abstract

Objectives: To trace the routes of transmission and sources ofStaphylococcus aureusfound in the surgical wound during cardiothoracic surgery and to investigate the possibility of reducing wound contamination, with regard to total counts of bacteria andS aureus, by wearing special scrub suits.Methods: A total of 65 elective operations for coronary artery bypass graft with or without concomitant valve replacement were investigated. All staff present in the operating room wore conventional scrub suits during 33 operations and special scrub suits during 32 operations. Bacteriological samples were taken from the hands of the scrubbed team after surgical scrub but before putting on sterile gowns and gloves and from the patients' skin (incisional area of sternum and vein harvesting area of legs) after preoperative skin preparation with chlorhexidine gluconate. Air samples were taken during operations. Bacteriological samples also were taken from the subcutaneous walls of the surgical wound just before closing the wound. Total counts of bacteria on sternal skin and wound walls (colony-forming units [CFUs//cm²) were calculated, as well as total counts of bacteria in the air (CFUs/m³). Strains ofS aureusrecovered from the different sampling sites were compared by pulsed-field gel electrophoresis (PFGE).Results: Special scrub suits significantly reduced total counts of bacteria in air compared to conventional scrub suits (P=.002). The number of air samples in whichS aureuswas found was significantly reduced by special scrub suits compared with conventional scrub suits (P=.016; relative risk, 4.4; 95% confidence interval [CI₉₅], 1.3-14.9]). By use of PFGE, it was possible to identify two cases of possible airborne transmission ofS aureuswhen wearing conventional scrub suits, whereas no case was found when wearing special scrub suits. When exposed to airborneS aureus, the concomitant sternal carriage ofS aureuswas a risk factor for havingS aureusin the wound.Conclusions: Use of tightly woven special scrub suits reduces the dispersal of total counts of bacteria and ofS aureusfrom staff in the operating room, thus possibly reducing the risk of airborne contamination of surgical wounds. The importance of careful preoperative disinfection of the patient's skin should be stressed.