Impact of alcohol-based, waterless hand antiseptic on the incidence of infection and colonization with methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci.

OBJECTIVE Colonized and infected inpatients are major reservoirs for methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), and transient carriage of these pathogens on the hands of healthcare workers remains the most common mechanism of patient-to-patient transmission. We hypothesized that use of alcohol-based, waterless hand antiseptic would lower the incidence of colonization and/or infection with MRSA and VRE. METHODS On June 19, 2001, alcohol hand antiseptic was introduced at the University campus and not the nearby Memorial campus of the University of Massachusetts Medical School (Worcester, MA), allowing us to evaluate the impact of this antiseptic on the incidence of MRSA and VRE colonization and infection. From January 1 through December 31, 2001, the incidence of MRSA colonization or infection was compared between the 2 campuses before and after the hand antiseptic was introduced. Its effect on VRE colonization and infection was only studied in the medical intensive care unit at the University campus. RESULTS At the University campus, the incidence of MRSA colonization or infection decreased from 1.26 cases/1,000 patient-days before the intervention to 0.75 cases/1,000 patient-days after the intervention, for a 1.46-fold decrease (95% confidence interval, 1.04-2.58; P = .037). At the Memorial campus, the incidence of MRSA colonization or infection remained virtually unchanged, from 0.34 cases/1,000 patient-days to 0.49 cases/1,000 patient-days during the same period. However, a separate analysis of the University campus data that controlled for proximity to prevalent cases did not show a significant improvement in the rates of infection or colonization. The incidence of nosocomial VRE colonization or infection before and after the hand antiseptic decreased from 12.0 cases/1,000 patient-days to 3.0 cases/1,000 patient-days, a 2.25-fold decrease (P = .018). Compliance with rectal surveillance for detection of VRE was 86% before and 84% after implementation of the hand antiseptic intervention. The prevalences of VRE cases during these 2 periods were 25% and 29%, respectively (P = .017). CONCLUSIONS Alcohol hand antiseptic appears to be effective in controlling the transmission of VRE. However, after controlling for proximity to prevalent cases (ie, for clustering), it does not appear to be more effective than standard methods for controlling MRSA. Further controlled studies are needed to evaluate its effectiveness.