Inappropriate treatment in children with bloody diarrhea: clinical and microbiological studies.

It is suggested that in dysentery physicians should treat empirically, as early treatment seems to improve outcome. A constantly updated knowledge of the relative frequency of enteropathogens and their sensitivity to antimicrobials is needed to choose the right therapy. We studied microbiological and clinical findings in 119 children with bloody diarrhea in Mexico City. Patients were divided into those < 1 year (infants) and those 1-5 years (children). Shigella was more frequent in children (35%) than in infants (10%). Campylobacter was more common in infants (29%) than in children (12%); Salmonella more frequent in infants (22%) than in children (8%); cytotoxic E. coli (EHEC) more frequent in children (20%) than in infants (13%). No cases of amebiasis were identified. Fever was the most sensitive indicator of infection for Shigella (70%), as compared for Salmonella (50%), Campylobacter (42%) and EHEC (36%); whereas specificity was about 50% for all pathogens. In contrast, the absence of fever was 80% predictive for the absence of these pathogens. In children with dysentery, the specific etiology cannot be predicted in the absence of culture. Almost 50% of the Shigella, Salmonella and EHEC isolates were resistant to ampicillin. In our community, the use of ampicillin and metronidazole should be discouraged.