Potential role of adherence traits of Escherichia coli in persistent diarrhea in an urban Brazilian slum.

We examined stools from 40 children with persistent diarrhea (duration, 14 days or more), from 50 children with acute diarrhea and from 38 control children to determine infectious etiologies for persistent diarrhea in Goncalves Dias, an urban favela (slum) in Fortaleza, Ceara, Brazil. Children with persistent diarrhea and children with acute diarrhea had similar rates of isolation of routine viral, bacterial and parasitic enteric pathogens. Routine pathogens were identified in at least 20% of cultures done more than 14 days into the diarrheal illness. We examined Escherichia coli isolated from these stools for adherence potential. Enteroaggregative E. coli were isolated significantly more often from children with persistent diarrhea than from control children or children with acute diarrhea (P less than 0.05). E. coli with hemagglutination patterns suggestive of adherence pili were also isolated more often from children with persistent diarrhea than from children with acute diarrhea (38% vs. 18%; P less than 0.05). Enterotoxigenic E. coli were isolated in combination with rotavirus more often from children with persistent diarrhea than from children with acute diarrhea. E. coli which were hydrophobic or exhibited hemagglutination were also seen more often in association with Giardia in children with persistent diarrhea. These findings suggest that the etiology of persistent diarrhea in children is complex and that the aggregative E. coli are associated with prolonged diarrheal illness. Although routine diarrheal pathogens may be present for more than 14 days, combinations of pathogens, including E. coli with adherence potential, may also contribute to prolonged diarrheal disease.

A prospective study of persistent diarrhea among children in an urban Brazilian slum. Patterns of occurrence and etiologic agents.

Persistent diarrhea is a major health problem among children in developing areas of the world. Since few community-based studies have addressed the epidemiology or etiology of this condition, we undertook prospective diarrheal surveillance among a cohort of 175 children less than 5 years of age over a 28-month period in an urban slum in northeastern Brazil. Very high diarrhea illness burdens were found. The children in this cohort had an average of 11 episodes per year and spent 82 days per year with diarrhea. A total of 65% of children had at least one episode of persistent diarrhea (greater than or equal to 14 days duration). These episodes accounted for 50% of all days of diarrhea and 11% of all episodes. The occurrence of at least one episode of persistent diarrhea identified all children who spent at least 15% percent of days with diarrhea. Among children with and without diarrhea, rotavirus was the agent isolated most frequently, followed by Giardia lamblia and enterotoxigenic coliforms. The agents isolated from children with acute and persistent diarrhea were similar, which suggests that other factors must be operative in the development of persistent diarrhea.