Control of vancomycin-resistant enterococci: one size fits all?

Infection caused by vancomycin-resistant enterococci (VRE) is associated with high morbidity and mortality rates; it poses a serious threat, in particular, to immunosuppressed patients. It generates high costs and challenges infection-control programs. Here, we look at the insights that mathematical models offer into the epidemiology of VRE colonization and infection, the potential benefits of various infection-control interventions, and the possibility of designing a tailored approach to controlling VRE. Models show that epidemics of VRE infection in diverse institutions may differ in the relative contributions of cross-transmission and the influx of new cases, as well as in the various mechanisms of local transmission. They also highlight the phenomenon of decreasing returns associated with many interventions and, hence, the need to identify the most important routes of transmission, to break the weakest links in the chain of transmission, and to contain the influx of cases of VRE infection. These observations also provide insights into the management of infection with other antibiotic-resistant nosocomial pathogens.