Enteroaggregative Escherichia coli may be a new pathogen causing acute and persistent diarrhea.

The role of Hep-2 cell adherent Escherichia coli (EAEC) of localized (EAEC-L), diffuse (EAEC-D) and aggregative (EAggEC) phenotype, was investigated in 254 children aged < or = 48 months seeking treatment for non-bloody diarrhea at an outpatient clinic, and in 107 age-matched controls. The stool excretion rates of single isolates from patients/controls for the different phenotypes of Hep-2 cell adherent E. coli were: EAEC-L, 5.9/2.8%, p = 0.33; EAEC-D, 7.5/12.1%, p = 0.22; and EAggEC, 11.8/3.7%, p = 0.03. When patients were categorized by pre-admission diarrheal duration > or = 14/< 14 days, the excretion rates were EAEC-L, 0/7.1%; EAEC-D, 9.5/7.1%, and EAggEC, 21.4/9.9%, the difference approaching significance only for EAggEC (p = 0.06). These findings suggest that EAggEC may be an important cause of diarrhea in children, with a predilection to cause prolonged disease.