title: Clinical predictors of acute bacterial diarrhea in young children.
abstract: This prospective study assessed the value of presenting history, physical examination, and screening laboratory tests in predicting whether diarrhea in a young child is associated with a stool culture positive for a bacterial pathogen. Acutely ill children less than 4 years old were studied in a hospital outpatient setting. Two hundred patients were seen in a 9 1/2-month period, which encompassed the seasons of summer, fall, and winter. One hundred ninety-five patients had cultures completed and twenty-nine (15%) had a bacterial pathogen isolated. The best predictive variable for a stool culture positive for a bacterial pathogen was the presence of polymorphonuclear cells in the stool, with a sensitivity of 85%, a specificity of 88%, and positive and negative predictive values of 59% and 97%, respectively. A cluster of three historical variables--abrupt onset of diarrhea, greater than four stools per day, and no vomiting before the onset of diarrhea--was identified that delineated a subpopulation of patients with an increased probability of having a stool culture positive for a bacterial pathogen (27% v 4% if any of the three variables was absent). It is suggested that these findings can be combined in a stepwise manner using the historical cluster as an initial screening, followed by examination for stool polymorphonuclear cells in the high probability subgroup, to identify those patients with a very high probability of having a bacterial pathogen isolated in their stool.
mesh_terms: D000333:Aeromonas / Q000302:isolation & purification; D001424:Bacterial Infections / Q000175:diagnosis*; D002167:Campylobacter / Q000302:isolation & purification; D002675:Child, Preschool; D003968:Diarrhea, Infantile / Q000175:diagnosis / Q000382:microbiology*; D005243:Feces / Q000382:microbiology; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012475:Salmonella / Q000302:isolation & purification; D012760:Shigella / Q000302:isolation & purification