isolated and non-isolated enteric pathogens in children with diarrhea and related laboratory characteristics

abstract background: diarrhea has been recognised as a major public health problem worldwide. aprospective study was performed to determine the etiology, seasonal and age prevalence, relevant laboratory investigations, sensitivity of isolated microorganisms to current medication, and practical approaches to the diagnosis and management of diarrhea in iran, as a developing country. methods: all infants and children under age five (n=825, mean age 18.9) admitted to tehran children’s hospital, tehran, with diarrheal symptoms during the period of april 2005 to march 2006 were included in the study 371 approximately age-matched controls (mean age 19.1 months) from the same hospital but not having diarrhea formed the control group. results: the most frequent isolated pathogen was escherichia coli (18.9%), followed by shigella spp (0.7%), and salmonella spp (0.4%). prevalence of diarrheic children with either isolated or non-isolated pathogens were 66.5% in the colder seasons and 54.4% in warm seasons. e. coli was more prevalent in children younger than two years old while sigella spp and salmonella spp were common to all ages. fecal leukocytes were associated with 100% of isolated escherichia coli, 19.4% of non-isolated organisms, 2.5% of shigella spp, 0.5% of salmonella spp and none in controls. escherichia coli was also associated with fecal red blood cells (29.4%), as were shigella spp (83%) and salmonella spp (33.3%). white blood cell counts, polymorphonuclear cells, band cells, erythrocyte sedimentation rate and c-reactive protein measurements had no diagnostic value. amikacin was the global choice of antimicrobial treatment for shigella spp in (99%) of cases and for escherichia coli in (91%) of isolated cases. only 70% of patients infected by salmonella showed sensitivity to gentamycin. conclusion: diarrheal diseases in either isolated or non-isolated pathogens were more prevalent in the colder seasons and in children younger than two years of age. for differentiation of bacterial from non-bacterial etiology, we had to wait for laboratory reports and then decide for antibiotic administration. the antibiotic most sensitive to echerichia coli and shigella was amikacin, and gentamycin was the most sensitive drug for salmonella.