Decreasing Trend of Surgical Site Infections among Surgical Patients in a University Hospital in Thailand after an Active Surveillance Program

Background: Reports from high-quality healthcare systems have shown that active surveillance and management of factors associated with surgical site infection (SSI) decreased the incidence and improved overall outcomes. Methods: This study aimed to appraise the incidence trend of SSIs during the 10-year period between 2007 and 2016 in a university hospital in a middle-income country, focusing on six high-risk and high-volume procedures. The study also examined factors associated with SSIs and their impact on surgical outcomes. Results: A total of 10,139 procedures in 9,661 cases were reviewed. The overall incidence of SSI was 2.98%. The incidence increased substantially with increasing risk score according to the National Nosocomial Infection Surveillance (NNIS) system risk score. The incidence trend decreased over time during the 10-year period studied. The procedures with the highest SSI incidence were craniotomy, colonic surgery, and cholecystectomy, which were also the three procedures that had standardized infection ratios (SIR) higher than 1.0 in all risk score categories. Univariable analysis found that diabetes mellitus was the only risk factor associated with SSI (odds ratio OR 1.81, 95% confidence interval CI 1.2–2.73). The majority of the positive cultures were gram-negative bacteria (45%) and 49% of all reported organisms were drug resistant. There were two important consequences of the infections: length of hospitalization increased substantially from 13 days to 24 days (p < 0.01) and patients with SSI had more than three times higher mortality rate (7% compared with 1.9%, p < 0.001). Conclusion: With active surveillance, the incidence of SSIs decreased to less than 2.0% over the 10-year study period. More intensive surveillance should implemented for operations with high SIR and cases with diabetes mellitus.