Fecal Colonization with Extended-spectrum Beta-lactamase-Producing Enterobacteriaceae and Risk Factors among Healthy Individuals: A Systematic Review and Metaanalysis

Background. Gut colonization is a risk factor for infections with extended-spectrum beta-lactamase (ESBL)-producing organisms. We aimed to determine the ESBL class A reservoir among healthy individuals. Methods. We searched PubMed and EMBASE (through 10 July 2015) looking for studies that contained data for fecal colonization with ESBL class A bacteria among healthy individuals for each World Health Organization-defined region. Distribution of isolates among cefotaximase (CTX-M), sulfhydryl variable, and temoneira enzymes and data on previous antibiotic use, international travel, previous hospitalization, and animal contacts were extracted. Results. Sixty-six of 17 479 studies on 28 909 healthy individuals were included. The pooled prevalence of ESBL class A colonization was 14% (95% confidence interval [CI], 9, 20), with an increasing trend of 5.38% annually (P =. 003). The pooled prevalence was higher in Asia and Africa (ranging from 46%, 95% CI, 29, 63 to 15%, 95% CI, 4, 31) and lower but still significant in central (3%, 95% CI, 1, 5), northern (4%, 95% CI, 2, 6), and southern Europe (6%, 95% CI, 1, 12) and the Americas (2%, 95% CI, 0, 5). CTX-Ms were the prevalent ESBL enzyme (69%). Antibiotic use for the prior 4 or 12 months was associated with a high colonization risk (risk ratio [RR] = 1.63; 95% CI, 1.19, 2.24 and RR = 1.58; 95% CI, 1.16, 2.16, respectively). International travel was also correlated with ESBL colonization [(RR = 4.06, (95% CI, 1.33, 12.41)]. Conclusions. The ESBL colonization rate among healthy individuals is significant worldwide. This should be taken into consideration in infection control and antibiotic management decisions.