Global Prevalence of Vancomycin-Resistant Enterococci in Food of Animal Origin: A Meta-Analysis

Vancomycin-resistant enterococci (VRE) are a leading cause of nosocomial infections in patients worldwide. VRE contamination in food of animal origin may create a risk for human health. This study was conducted to estimate the pooled prevalence of VRE in food of animal origin worldwide, to assess the result heterogeneity, and to determine cumulative evidence and the trend of the prevalence over time. Relevant studies were retrieved from PubMed, Scopus, and Web of Science. A random-effects model was used to calculate the pooled prevalence of VRE in food of animal origin. Subgroup meta-analysis was used to assess the heterogeneity of the results. A cumulative meta-analysis and meta-regression were conducted to determine cumulative evidence and the trend of the prevalence of VRE in food of animal origin over time, respectively. Of the 1352 retrieved studies, 50 articles were included. The pooled prevalence of VRE in food of animal origin was 11.7% (95% confidence interval 95% CI = 8.4 to 16.0). Subgroup meta-analyses showed a significant difference in the prevalence of VRE for two characteristics. First, for the source of food, the prevalence of VRE was highest in aquatic food (43.4% 95% CI = 28.4 to 59.7) and lowest in dairy food (4.1% 95% CI = 1.7 to 9.8). Second, for continents, the prevalence of VRE was highest in Africa (18.5% 95% CI = 12.8 to 26.1) and lowest in North America (0.3% 95% CI = 0.1 to 1.1). Cumulative evidence showed two distinct features in two different periods. The pooled prevalence of VRE rapidly decreased from 79.3% in 1998 to 13.1% in 2003; it has slightly fluctuated between 10.5% and 20.5% since 2004. The results of the meta-regression indicated that the prevalence gradually decreased over time. In conclusion, the estimate of overall VRE prevalence worldwide in food of animal origin was ∼12%, indicating the burden of VRE contamination in food of animal origin.