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.