LAUSR

Antimicrobial resistance has been recognized as one of the main public health problems worldwide and demands prompt actions from healthcare institutions and policymakers.1 The core strategies in the battle against antimicrobial resistance are (1) to discover new antibiotics that can be safely and efficaciously used in clinical practice, (2) to optimize the use of currently available antimicrobials and (3) to limit the transmission of antibiotic-resistant microorganisms.2 As this is a complex, global and multifaceted problem it is critical that all core strategies are applied with a “One Health” perspective, considering human and animal health as well as environmental issues. Enterococcus faecium is the first of the microorganisms included in the ESKAPE acronym, which contains six of the most priority pathogens for which antimicrobial resistance represents a clinically-relevant problem.3 Fortunately, the rate of vancomycin resistance among E. faecium isolates in Spain remains below 5% and outbreaks have seldom been reported.4 Nevertheless, vancomycinresistant E. faecium (VREF) has a considerable potential to spread in healthcare institutions and, therefore, to cause outbreaks and become endemic. Acquainting the epidemiology of VREF is critical to control its spread. The gastrointestinal (GI) tract of infected and or colonized patients is the main reservoir of VREF. The number of patients colonized by VREF significantly exceeds the number of infected patients since estimated infection:colonization ratio is 10:1.5 GI colonization can be prolonged, with a model-estimated median duration of 26 weeks.6 Importantly, enterococci are capable to persist in hospital environment. The main risk factors for VRE acquisition are prior antimicrobial use, colonization pressure and exposure to other patients, devices, other invasive procedures and contaminated surfaces. Consequently, although infection-control interventions have to be adapted to the epidemiological setting, frequently a combination of hand hygiene, contact precautions, active surveillance, enhanced environmental cleaning and antimicrobial stewardship are necessary to control VRE outbreaks.5