Effectiveness of Prudent Use of Vancomycin After a Vancomycin Resistant Enterococci (VRE) Outbreak in a Non-endemic, Tertiary Care Hospital

Abstract

Background. Antimicrobial stewardship program (ASP) of vancomycin enforced appropriate formulary prescription. The program was able to reduce VRE colonization and infection rate, as a part of a multifaceted intervention. Limited studies demonstrated effectiveness of ASP alone in decreasing incidence of VRE in hospitals. Methods. After a VRE outbreak in a 500-bed, university-affiliated, tertiary care hospital in Bangkok, during 28 July 28-1 September 2015, a multifaceted intervention was promptly implemented including contact isolation precautions, active surveillance culture (ASC), cohorting patients who was colonized or infected with VRE, environmental decontamination with 1:100 sodium hypochlorite solution and hydrogen peroxide vapor, enhance hand hygiene compliance, and implementing vancomycin prescription restriction policy. We conducted a hospital-wide, prospective, quasi-experimental study for a 6-month period before intervention (period 1), a 2-month period of program implementation ( period 2), and a 6-month period after intervention (period 3). No interventions were continued in period 3 except vancomycin prescription restriction policy. We evaluated appropriate used of vancomycin based on Healthcare Infection Control Practices Advisory Committee (HICPAC) recommendation and compared between period 1 and 3. We used defined daily dose (DDD), recommended by the World Health Organization, to compare in-hospital vancomycin utilization. We also compared incidence of VRE colonization/infections between these periods. Results. Appropriate used of vancomycin was increased by 32.6% of prescriptions (40.5% [42/104] versus 73.1% [57/78], p < 0.001). Decrease of vancomycin consumption was observed (-17.9%, 1.84 to 1.51 DDDs/100 bed-days, p = 0.02). Incidence of VRE infection was decreased from 0.25/1000 patient-days during the outbreak to zero in a month after the program (p < 0.001). We sustained zero incidence of VRE infection for 6 months after the outbreak. ASC was done among patients in the unit having highest incidence of VRE during the outbreak and found no colonization of the organism (0/27 cases) in period 3 of the study. Conclusion. Multifaceted interventions resulted in control of VRE outbreak. In non-endemic setting, vancomycin prescription restriction policy may be a key element in sustained reduction of VRE colonization and infection.