Vancomycin-resistant enterococci in intensive care hospital settings

Vancomycin-resistant enterococci (VRE) have recently emerged as a nosocomical pathogen and present an increasing threat to the treatment of severely ill patients in intensive-care hospital settings. We outline results of a study of the epidemiology of VRE transmission in ICUs and define a reproductive number R-0; the number of secondary colonization cases induced by a single VRE-colonized patient in a VRE-free ICU, for VRE transmission. For VRE to become endemic requires R-0 > 1. We estimate that in the absence of infection control measured R-0 lies in the range 3-4 in defined ICU settings. Once infection control measures are included R-0 = 0.6, suggesting that admission of VRE-colonized patients can stabilize endemic VRE.