Hospital-acquired infections caused by enterococci: a systematic review and meta-analysis, WHO European Region, 1 January 2010 to 4 February 2020

Background Hospital-acquired infections (HAI) caused by Enterococcus spp., especially vancomycin-resistant Enterococcus spp. (VRE), are of rising concern. Aim We summarised data on incidence, mortality and proportion of HAI caused by enterococci in the World Health Organization European Region. Methods We searched Medline and Embase for articles published between 1 January 2010 and 4 February 2020. Random-effects meta-analyses were performed to obtain pooled estimates. Results We included 75 studies. Enterococcus spp. and VRE accounted for 10.9% (95% confidence interval (CI): 8.7–13.4; range: 6.1–17.5) and 1.1% (95% CI: 0.21–2.7; range: 0.39–2.0) of all pathogens isolated from patients with HAI. Hospital wide, the pooled incidence of HAI caused by Enterococcus spp. ranged between 0.7 and 24.8 cases per 1,000 patients (pooled estimate: 6.9; 95% CI: 0.76–19.0). In intensive care units (ICU), pooled incidence of HAI caused by Enterococcus spp. and VRE was 9.6 (95% CI: 6.3–13.5; range: 0.39–36.0) and 2.6 (95% CI: 0.53–5.8; range: 0–9.7). Hospital wide, the pooled vancomycin resistance proportion among Enterococcus spp. HAI isolates was 7.3% (95% CI: 1.5–16.3; range: 2.6–11.5). In ICU, this proportion was 11.5% (95% CI: 4.7–20.1; range: 0–40.0). Among patients with hospital-acquired bloodstream infections with Enterococcus spp., pooled all-cause mortality was 21.9% (95% CI: 15.7–28.9; range: 14.3–32.3); whereas all-cause mortality attributable to VRE was 33.5% (95% CI: 13.0–57.3; range: 14.3–41.3). Conclusions Infections caused by Enterococcus spp. are frequently identified among hospital patients and associated with high mortality.