Impact of Enhanced Infection Control Measures on Hospital-Acquired Carbapenem-Resistant Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii

Background: Carbapenem-resistant organisms (CROs) represent a major cause of healthcare-acquired infections. This study aims to evaluate the impact of enhanced infection control measures on the incidence of hospital-acquired carbapenem-resistant Klebsiella pneumoniae, Escherichia coli, Pseudomonas aeruginosa , and Acinetobacter baumannii infections. Given resource constraints, other CROs were excluded from the analysis. Methods: This study was conducted at a tertiary hospital in China. The baseline period (Period 1) spanned from January 1, 2022, to December 31, 2023. Starting January 1, 2024, an enhanced intervention (Period 2) was implemented, comprising weekly active surveillance for CROs, coupled with immediate notification and on-site audit with feedback to ensure prompt implementation of contact isolation for positive cases. The study compared the trends of CROs, incidence rates of hospital-acquired CROs infections, contact isolation order compliance rates, and the consumption intensity of carbapenems between the two periods. An interrupted time-series analysis was used to assess the intervention effect. Results: The incidence of CROs increased by 0.101 cases per 1000 patient-days per quarter in period 1 (95% CI: 0.006– 0.209, p = 0.043), whereas it decreased by 0.179 cases per 1000 patient-days per quarter in period 2 (95% CI: − 0.331 to − 0.026, p = 0.025). Similarly, the rate of hospital-acquired CROs infections increased by 0.021 cases per 1000 patient-days per quarter in period 1 (95% CI: 0.008– 0.0327, p = 0.003), but declined by 0.034 cases per 1000 patient-days per quarter in period 2 (95% CI: − 0.051 to − 0.017, p = 0.001). Concurrently, compliance with contact isolation orders improved markedly from 35.37% to 78.83% ( p < 0.001). In contrast, carbapenem consumption showed a sustained upward trend throughout the study period, increasing by 1.012 defined daily doses per 1000 patient-days per quarter ( p = 0.003), with no significant difference in trend between the two periods ( p = 0.105). Conclusion: Enhanced infection control measures were associated with a reduction in hospital-acquired CROs infections. Keywords: carbapenem-resistant organisms, hospital-acquired, infection control, contact isolation, antimicrobial consumption