Abstract
BACKGROUND: Postoperative bloodstream infection (PBSI) is a severe complication in gynecological surgery, associated with higher morbidity than surgical site infections. However, large-scale data on PBSI epidemiology and risk factors, particularly from the Chinese population and within modern Enhanced Recovery After Surgery (ERAS) pathways, are scarce. This study aimed to define the incidence, etiology, and modifiable risk factors for PBSI in a major Chinese tertiary center. METHODS: We conducted a three-year (Jan 2022–Dec 2024) retrospective cohort study of 19,906 patients undergoing gynecological surgery. Data were extracted from electronic medical records to determine the incidence of postoperative fever (PF) and PBSI. Pathogen distribution, antimicrobial susceptibility, and risk factors were analyzed using univariable and multivariable logistic regression models. RESULTS: The overall incidence of PF was 2.67% and PBSI was 1.30%. The institutional rate of preoperative vaginal preparation was strongly and inversely correlated with PBSI incidence (ρ = -0.50, P = 0.002). Multivariable analysis identified several independent risk factors, including combined high-risk surgery (aOR 3.72; 95% CI, 2.84–4.89), and seasonality, with peak risk in Q3 (aOR 2.03; 95% CI, 1.41–2.96). Escherichia coli was the predominant pathogen in culture-positive PBSI (70.37%), exhibiting high resistance to the first- and second-generation cephalosporins commonly used for prophylaxis, but remained susceptible to carbapenems and β-lactam/β-lactamase inhibitors. CONCLUSIONS: The implementation of preoperative vaginal preparation as a core component of a quality improvement initiative was associated with a lower institutional PBSI rate. The high prevalence of resistant E. coli likely neutralizes the effectiveness of standard antibiotic prophylaxis, mandating a shift towards antibiotic stewardship guided by local antibiograms. Risk stratification should also account for surgical complexity and seasonal peaks. These findings provide a data-driven framework for optimizing infection prevention strategies in modern gynecological surgery. CLINICAL TRIAL REGISTRATION NUMBER: Not applicable.