Colonization with enteroadherent, enterotoxigenic and enterohemorrhagic Escherichia coli among day-care center attendees in New Orleans, Louisiana

Background. E. coil strains producing specific virulence factors are freque ntly cited as causes of pediatric diarrhea in developing areas, although ma ny well children from the same areas are colonized with these organisms, Th e role of these Escherichia coil in day-care center (DCC)associated diarrhe a in the United States has not been evaluated. Methods. A cohort of 112 DCC attendees from 5 DCC in urban New Orleans were followed longitudinally with demographic data, biweekly routine stool samp les and additional stool samples with episodes of diarrhea, E, coli isolate s were routinely saved; diarrhea stool samples were tested to detect entero toxigenic, enterohemorrhagic and enteroadherent strains; and the prevalence of these E. coil in children with and without diarrhea was investigated, Results. During 225 child months of observation 21 episodes of diarrhea wer e documented and microbiologic data were available for 18, HEp-2 cell enter oadherent E. coli [mostly enteroaggregative (EAggEC) pattern] were identifi ed in 6 of 18 (33.3%) diarrhea cases vs. 6 of 36 (16.6%) age-matched contro ls. However, the prevalence of EAggEC was very DCC-specific, with EAggEC fo und in 12 of 22 routine specimens from a DCC with recent EAggEC-related dia rrhea vs. 0 of 11 routine specimens from age-matched children in another DC C without EAggEC-related diarrhea (P = 0.002), Enterotoxigenic E, coli were uncommon in both ill and well children, and no enterohemorrhagic E. coli w ere detected, Conclusion. EAggEC were commonly isolated from children with and without di arrhea in certain DCC settings, although we cannot determine whether these strains caused diarrhea. Diarrhea-producing E, coli were not associated wit h diarrhea in this DCC population.