To investigate the rates of Staphylococcus aureus carriage on the hands and in the noses of healthcare workers (HCWs) and the relatedness of S. aureus isolates found in the two sites.

Point-prevalence study.

Department for Thoracic and Cardiovascular Surgery at the University Hospital of Uppsala, Uppsala, Sweden.

Samples were obtained from 133 individuals, 18 men and 115 women, using imprints of each hand on blood agar and a swab from the nose. S. aureus isolates were identified by standard methods and typed by pulsed-field gel electrophoresis.

S. aureus was found on the hands of 16.7% of the men and 9.6% of the women, and in the noses of 33.3% of the men and 17.4% of the women. The risk ratio for S. aureus carriage on the hands with nasal carriage was 7.4 (95% confidence interval, 2.7 to 20.2; P < .001). Among the 14 HCWs carrying S. aureus on their hands, strain likeness to the nasal isolate was documented for 7 (50%).

Half of the HCWs acquired S. aureus on the hands from patients or the environment and half did so by apparent self-inoculation from the nose. Regardless of the source of contamination, good compliance with hand hygiene is needed from all HCWs to protect patients from nosocomial infections. The moderate rate of S. aureus carriage on hands in this setting could be the result of the routine use of alcoholic hand antisepsis.

To trace the routes of transmission and sources of Staphylococcus aureus found in the surgical wound during cardiothoracic surgery and to investigate the possibility of reducing wound contamination, with regard to total counts of bacteria and S aureus, by wearing special scrub suits.

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 of S aureus recovered from the different sampling sites were compared by pulsed-field gel electrophoresis (PFGE).

Special scrub suits significantly reduced total counts of bacteria in air compared to conventional scrub suits (P=.002). The number of air samples in which S aureus was 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 of S aureus when wearing conventional scrub suits, whereas no case was found when wearing special scrub suits. When exposed to airborne S aureus, the concomitant sternal carriage of S aureus was a risk factor for having S aureus in the wound.

Use of tightly woven special scrub suits reduces the dispersal of total counts of bacteria and of S aureus from 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.