Emergency of vancomycin-resistant Enterococcus infections in a teaching hospital in Chile

An active surveillance of vancomycin-resistant enterococci (VRE) intestinal colonization in selected group of patients has been developed in Chile since year 2000. Nevertheless, no reports of clinical cases have been published. Aim. To describe clinical and microbiological features of patients infected by VRE in a tertiary-level teaching Hospital. Patients and methods. Intestinal and clinical samples positive to VRE were provided by laboratory, and a retrospective analysis of potential risk factors, clinical features, treatment and outcomes was performed. Study encompassed years 2001 to 2006. Main results. 23 cases of infections were identified, all cases occurring during 2005 and 2006. Incidence rate was 0.07 and 0.09 cases per 1000 occupied bed-days, respectively. The mean age was 62.0 +/- 17 years. A significant proportion of patients had cancer (39.1%), recent surgical procedures (54.1%), were on dialysis (26.1%), or were using steroids (26.1%). Most patients had received 2 or more antimicrobial (87%), almost a third represented transfers from other hospitals and an additional 22% readmissions before 30 days of latest discharge. Patients were mainly hospitalized in the ICU (60.9%) but nearly 30% were associated exclusively to nephrological or onco-hematological wards. Clinical manifestations included bacteremia (30.4%), surgical site infections or abscesses (26.1%), urinary tract infections (26.1%) and others. Three patients (13%) did not have symptoms. After identification was possible, all isolates were identified as E. faecium (82.6% of total), the rest as Enterococcus sp. Most strains showed intermediate susceptibility to vancomycin (66.7%). For 14 strains studied both with vancomycin and teicoplanin,, phenotype Van B was predominant (85.7%), followed by VanA (7.1%) and VanB/VanD type (7.1%). No molecular studies were performed. Fifteen patients (65.4%) received a surgical and/or medical treatment. A favorable response was observed in 80% of these cases. Eight patients were not treated (34-8%), in 2 cases because of a rapidly-fatal infection. The global risk-fatality ratio for VRE infections was 13% and increased to 42.9% in patients with bacteremia. Microbiological eradication was documented in 52.2%.