Surgical site infections in a tertiary health care center: prospective cohort study

To investigate the incidence and risk factors associated with the development of surgical site infections (SSIs) using the National Nosocomial Infection Surveillance (NNIS).

A prospective cohort study was conducted at a tertiary health care center. Infection control personnel collected general and health care related data about patients. The NNIS risk index was calculated on the basis of data relating to the operation: wound contamination class, duration of surgery, and the American Society of Anesthesiologists (ASA) score.

A total of 5109 surgical procedures were included in the study. The overall cumulative incidence rate was 6.3%. The incidence of SSIs was 2.3% (63.5% of operative procedures), 8.3% (29.7%), 34.6% (6.2%), and 43.3% (0.6%), in patients with 0, 1, 2, and 3 risk index, respectively. The length of hospital stay (OR: 1.0; 95% CI: 1.053-1.075), preoperative length of stay (odds ratio [OR]: 1.9; 95% confidence interval [CI]: 1.953-1.981), antibiotic prophylaxis (OR: 2.5; 95% CI: 1.421-4.628), drainage (OR: 1.7; 95% CI: 1.360-2.353), ASA score (OR: 1.5; 95% CI: 1.235-1.946), class of wound contamination (OR: 2.0; 95% CI: 1.745-2.003), and NNIS risk index (OR: 1.3; 95% CI: 1.063-1.7) were independently associated with an increased risk for SSIs. Staphylococcus aureus was the most frequently isolated microorganism, 64% of them being methicillin-resistant.

The aim of this study was to investigate the most important risk factors associated with the development of surgical site infections (SSIs). Therefore, greater attention has been given to adherence to recommendations for the prevention and control of SSIs as well as to antibiotic prophylaxis protocols.