A prospective study of enteropathogenic Escherichia coli in endemic diarrheal disease.

The rate of isolation of Escherichia coli belonging to the traditional serotypes enteropathogenic for infants was studied prospectively in two groups. Group 1 consisted of children with diarrhea and of controls without gastrointestinal disease who were matched for age and inpatient or outpatient status. Group 2 consisted of families entered in a prospective study of rotavirus infections. In group 1 enteropathogenic Escherichia coli were found in 13 (6%) of 220 children younger than 12 months of age and in nine (6%) of 143 children 12--35 months of age, all of whom had diarrhea. Enteropathogenic E. coli were found in only one of an equal number of matched controls (P = 0.002 and 0.004, respectively). In group 2 enteropathogenic E. coli were present in seven (18%) of 38 specimens obtained during diarrheal episodes, as compared with five (1%) of 492 specimens obtained when there was no diarrhea (P less than 0.001). The enteropathogenic E. coli isolated were not enterotoxigenic. The most common serogroup was O111, but many different O:H serotypes were detected. Thus, the association of enteropathogenic E. coli with endemic diarrhea was significant, even though no enteropathogenic mechanism was apparent.