Surgical site infections in an Italian surgical ward: a prospective study.

BACKGROUND: Surgical site infection (SSI) remains a major cause of morbidity and death. This study analyzed the results of surveillance to evaluate the incidence, risk factors, and characteristics of SSI in patients who underwent an operation in a typical Italian surgical ward.

METHODS: A group of 1,281 patients operated on from August 2005 to December 2007 underwent prospective and direct observation of incisions by a surgeon according to the U.S. Centers for Disease Control and Prevention (CDC) National Nosocomial Infections Surveillance (NNIS) method. The minimum follow-up was 30 days. A locally-modified risk index score (LRI) based on the NNIS was calculated for each patient, using as a cut point the 75(th) percentile of the duration of surgery (in minutes) for that particular procedure.

RESULTS: Seventy-six patients were affected by incision site infection, and the SSI rate was 5.9%. Thirty-four (2.6% of the series) were superficial incisional, 32 (2.5%) deep incisional, and 10 (0.8%) organ/space SSIs. An increasing value of the LRI was significantly (p < 0.05) related to an increasing risk of infection. The SSI rates were 0.6%, 3.7%, 7.3%, and 26.8% for LRI value of M = - 1, 0, 1, and >or=2, respectively. Obesity (body mass index >30 kg/m(2)), diabetes mellitus, and emergency surgery were associated with a higher risk of infection by multivariable analysis independent of the LRI.

CONCLUSIONS: The NNIS method can be useful for SSI surveillance and monitoring in single surgical wards. Longer operations, diabetes mellitus, and obesity increase the risk of SSI, as does performance of surgery in an emergency situation.