Prevalence of Hepatitis E Virus Antibodies Among Blood Donors: A Systematic Review and Meta-Analysis

Context: Hepatitis E virus (HEV) is well-known to be transmitted by the fecal-oral route. In addition, several studies in Europe and Asia had reported potential HEV transmission associated with blood transfusion, but this route is still uncertain. Objective: The aim of this study was to estimate the anti-HEV IgG seroprevalence among blood donors around the world using the Bayesian-based methods. Evidence Acquisition: A systematic review was performed using the PubMed/Medline, Scopus, Web of Science and Cochrane Library databases using the terms "prevalence", "hepatitis E" and "blood donors". Studies with a timeframe from inception to March 2016, in Roman characters, that had outcomes of interest such as prevalence of IgG antibodies were included. The estimation of anti-HEV IgG (presented as the event rate and 95% confidence intervals, CI) was performed using a Bayesian-based random effect model using the Comprehensive Meta-Analysis software, version 2. Pairwise meta-analyses and chi-square tests were used to assess significant differences between different sexes and ages. Results and Conclusions: Of the retrieved studies, 71 met the inclusion criteria, comprising a total of 113 316 blood donors. The prevalence rate was statistically significant in males and over 40 years old donors (P < 0.05). The overall estimation of the anti-HEV IgG prevalence was 0.058 (CI 95%: 0.049 - 0.068). Subgrouping by region, the estimates were higher for Asia and the Middle East, respectively: 0.113 (CI 95%: 0.040 - 0.278) and 0.112 (CI 95%: 0.081 - 0.152). Europe, Africa, Oceania and America had an estimated prevalence between 0.014 and 0.088. A relevant prevalence of anti-HEV IgG among blood donors was found worldwide, especially in Asia and the Middle East and in males and donors over 40 years. This review reinforces the view that HEV parenteral route infection needs to be further investigated and possibly screened for in transfused blood.