Enteroaggregative Escherichia coli Is a Cause of Acute Diarrheal Illness: A Meta-Analysis

BACKGROUND: Conflicting studies exist regarding the role of enteroaggregative Escherichia coli (EAEC) as a cause of acute diarrheal illness. The objective of this meta-analysis was to determine whether identification of EAEC in stool samples is associated with acute diarrheal illness among different subpopulations, by geographic area. METHODS: A comprehensive search of electronic bibliographic databases (Medline and PubMed) from August 1985 to January 2006, as well as a search of conference proceedings, references of articles, and contacts with investigators of EAEC, yielded 354 studies. RESULTS: Forty-one studies (12%) that met the selection criteria (i.e., that examined the association between acute diarrheal illness and the excretion of EAEC among different subpopulations) were included. In this meta-analysis, presence of EAEC identified with the HEp-2 cell adherence assay was found to be significantly associated with acute diarrheal illness among children residing in developing regions (odds ratio OR, 1.58; 95% confidence interval CI, 1.36-1.83) and industrialized regions (OR, 1.23; 95% CI, 1.03-1.48), adults with human immunodeficiency virus infection residing in developing regions (OR, 6.43; 95% CI, 2.91-14.16), adults residing in developing regions (OR, 7.15; 95% CI, 1.96-26.04), and international travelers to developing regions (OR, 6.72; 95% CI, 2.62-17.20). A limited number of studies were available that examined the role of EAEC identified by its virulence genes by a DNA probe. CONCLUSIONS: On the basis of this meta-analysis, we conclude that EAEC is a cause of acute diarrheal illness among many different subpopulations in both developing and industrialized regions, that EAEC strains are very heterogeneous and that additional studies that examine the role of EAEC in acute diarrheal illness are needed.