Diarrhea in a non-hospitalized rural Salvadoran population: the role of enterotoxigenic Escherichia coli and rotavirus.

To determine the role of rotavirus, enterotoxigenic Escherichia coli and enteropathogenic E. coli in diarrheal disease of non-hospitalized children and adults living in rural El Salvador, stool specimens were collected from 156 persons with diarrhea and 134 age- and sex-matched controls over a 1-year period. Enterotoxigenic Escherichia coli (ETEC) were isolated as frequently from controls (13.4%) as from diarrhea cases (12.2%). Enteropathogenic E. coli were isolated from 13 cases (8.3%) and 10 (7.7%) controls. Rotavirus was demonstrated in only five of the 129 specimens from cases examined; the five persons infected were less than or equal to 3 years of age. No invasive E. coli were found. Serotyping of ETEC revealed serogroups of ETEC previously associated with enterotoxigenicity but was not helpful in separating infection from disease. The etiology of diarrhea in this rural, non-hospitalized population was complex. Isolation of a known pathogen did not prove etiology. The rotaviruses, which have been isolated frequently from hospitalized persons, were rare. Further laboratory and epidemiologic studies in such populations are needed to identify those factors that determine pathogenicity.