Colonization with vancomycin-resistant enterococci and risk for bloodstream infection among patients with malignancy: A systematic review and meta-analysis

Background. Vancomycin-resistant enterococci (VRE) cause severe infections among patients with malignancy, and these infections are usually preceded by gastrointestinal colonization. Methods. We searched the PubMed and EMBASE databases (up to May 26, 2016) to identify studies that reported data on VRE gastrointestinal colonization among patients with solid or hematologic malignancy. Results. Thirty-four studies, reporting data on 8391 patients with malignancy, were included in our analysis. The pooled prevalence of VRE colonization in this population was 20% (95% confidence interval [CI], 14%-26%). Among patients with hematologic malignancy, 24% (95% CI, 16%-34%) were colonized with VRE, whereas no studies reported data solely on patients with solid malignancy. Patients with acute leukemia were at higher risk for VRE colonization (risk ratio [RR] = 1.95; 95% CI, 1.17-3.26). Vancomycin use or hospitalization within 3 months were associated with increased colonization risk (RR = 1.92, 95% CI = 1.06-3.45 and RR = 4.68, 95% CI = 1.66-13.21, respectively). Among the different geographic regions, VRE colonization rate was 21% in North America (95% CI, 13%-31%), 20% in Europe (95% CI, 9%-34%), 23% in Asia (95% CI, 13%-38%), and 4% in Oceania (95% CI, 2%-6%). More importantly, colonized patients were 24.15 (95% CI, 10.27-56.79) times more likely to develop a bloodstream infection due to VRE than noncolonized patients. Conclusions. A substantial VRE colonization burden exists among patients with malignancy, and colonization greatly increases the risk for subsequent VRE bloodstream infection. Adherence to antimicrobial stewardship is needed, and a re-evaluation of the use of vancomycin as empiric therapy in this patient population may be warranted.