The effect of active surveillance for vancomycin-resistant enterococci in high-risk units on vancomycin-resistant enterococci incidence hospital-wide

Background. Vancomycin-resistant enterococci (VRE) have become a major cause of nosocomial Infections and are now endemic in many geographic areas, The aim of this study was to describe the effect of active surveillance for patients with VRE in high-risk units on the VRE incidence rate hospital-wide. Methods: We determined 4 time periods based on the intervention of active surveillance: preactive surveillance (period 1), active surveillance (period 2), no active surveillance (period 3), and reinstutition of active surveillance (period 4). VRE incidence rates based on first clinical culture for VRE per 10,000 patient days for each of these periods and incidence rate ratios were then calculated. Results: Active surveillance in high-risk units was associated with a significant reduction in VRE incidence hospital-wide in 2 of the 3 comparisons made. The incidence rate ratio when comparing the first period of active surveillance (period 2) to the preactive surveillance period (period 1) was 0.63 (95 % Cl, 0.38-1.1) it was 0.36 (95 % Cl, 0.23-0.55) when comparing the first period of active surveillance (period 2) to the subsequent period (period 3) and 0.68 (95% Cl, 0.54-0.85) when comparing the second period of active surveillance (period 4) to the prior period without active surveillance periods, Conclusions: Active surveillance culturing for VRE in the high risk-units prevented further VRE transmission, as evidenced by a significant increase in hospital-wide incidence rates when active surveillance was discontinued and a significant decrease in incidence rates when it was restarted.