Impact of surface disinfection with hydrogen peroxide on the prevalence of vancomycin-resistant enterococci (VRE) in hospital wards

Objective: Vancomycin-resistant enterococci (VRE) are of major concern in infection control. Although broad infection control actions to check VRE have been implemented, VRE remain part of daily infection prevention in clinical settings. Cleaning procedures in the inanimate ward environment might play a key role in controlling VRE. In order to optimize infection control management at University Hospital Frankfurt, Germany (UHF), this study evaluates the impact of H2O2-containing cleaning wipes compared to Glucoprotamin containing wipes on VRE prevalence in intensive care wards. Methods: Retrospective analyses were conducted of the VRE prevalence on environmental materials obtained from three intensive care units (ICU) at UHF for 17 months prior to (T1) and during the 25 months after (T2) the implementation of H2O2-containing cleaning wipes from January 2016 to June 2019. The bactericidal power of the two disinfectants against VRE was compared using the 4-field test according to EN 16615 Results: At T1 and T2, n=666 and n=710 environmental samples, respectively, were obtained. At T1, 24.2% (n=161/666; 95% confidence interval: 21.0-27.6) and at T2, 6.9% (n=49/710; 5.1-9.0) samples were positive for VRE. In vitro disinfectant testing did not reveal any superiority of H2O2 over glucoprotamin. No effect on the VRE prevalence in patients' rectal screening materials was observed. Conclusion: Though Glucoprotamin and H2O2 were in vitro equally effective against VRE, the prevalence of VRE in ICU environment at UHF decreased after implementation of H2O2-containig wipes. This might be due to multiple factors, of which we consider the impact of the Hawthorne effect to be the strongest. Success of infection control strategies might depend on the compliance of the persons critically involved. Transparent information on infection control strategies is suggested to increase compliance and should therefore be considered both in daily infection control and outbreak management.