Diarrhea etiology in a Children's Hospital Emergency Department: a prospective cohort study.

BACKGROUND: We evaluated the frequency of recovery of pathogens from children with diarrhea who presented to a pediatric emergency department and characterized the associated illnesses, to develop guidelines for performing a bacterial enteric culture. METHODS: We conducted a prospective cohort study of all patients with diarrhea who presented to a large regional pediatric emergency department during the period from November 1998 through October 2001. A thorough microbiologic evaluation was performed on stool specimens, and the findings were correlated with case, physician, and laboratory data. RESULTS: A total of 1626 stool specimens were studied to detect diarrheagenic bacteria and, if there was a sufficient amount of stool, Clostridium difficile toxin (688 specimens), parasites (656 specimens), and viruses (417 specimens). One hundred seventy-six (47%) of 372 specimens that underwent complete testing yielded a bacterial pathogen (Shiga toxin-producing Escherichia coli, 39 specimens [of which 28 were serotype O157:H7]; Salmonella species, 39; Campylobacter species, 25; Shigella species, 14; and Yersinia enterocolitica, 2), a viral pathogen (rotavirus, 85 specimens; astrovirus, 27; adenovirus, 18; or rotavirus and astrovirus, 8), a diarrheagenic parasite (5 specimens); or C. difficile toxin (46 specimens). Samples from 2 patients yielded both bacterial and viral pathogens. A model to identify predictors of bacterial infection found that international travel, fever, and the passing of >10 stools in the prior 24 h were associated with the presence of a bacterial pathogen. Physician judgment regarding the need to perform a stool culture was almost as accurate as the model in predicting bacterial pathogens. CONCLUSIONS: Nearly one-half of the patients who presented to the emergency department with diarrhea had a definite or plausible pathogen in their stool specimens. We were unable to develop a model that was substantially better than physician judgment in identifying patients for whom bacterial culture would yield positive results. The unexpectedly high rate of C. difficile toxin warrants further examination.

Etiology of diarrhea in pediatric outpatient settings.

BACKGROUND: The frequency with which bacteria cause diarrhea evaluated in ambulatory settings is often unknown. We attempted to determine the microbiologic etiology of diarrhea in a private pediatric practice (site A) and a clinic serving largely immigrant children (site B) and to establish guidelines for bacterial culture. METHODS: Children with diarrhea were prospectively enrolled, and their stools were examined for diarrheagenic bacteria, viruses and parasites. RESULTS: A total of 123 and 103 children were enrolled at sites A and B, respectively. Stools from all (100%), 126 (55.8%), 104 (46.0%) and 75 (33.2%) were tested for bacterial enteric pathogens, parasites, Clostridium difficile toxin and viruses, respectively. Of the 75 patients whose stool underwent complete testing, 36 (48%) contained at least 1 definitive or plausible pathogen. Twelve stools (5.3%) tested positive for bacteria [Campylobacter jejuni (n = 7), Yersinia enterocolitica, Shigella flexneri, Shigella sonnei, Salmonella serogroup D and Salmonella Braenderup (n = 1 each)]. One contained Blastocystis hominis, 8 contained C. difficile toxin and 16 contained viruses (9 rotavirus, 5 adenovirus and 2 astrovirus). Visible fecal blood (P = 0.029), increased stool frequency (P = 0.035), abdominal tenderness (P = 0.011) and fecal white (P < 0.001) or red blood cells (P = 0.002) were associated with bacterial infection. All children with stool yielding diarrheagenic bacteria or C. difficile toxin had at least 1 of these factors, but so did 75% of children without these agents (positive predictive value, 11%; negative predictive value, 100%; sensitivity, 100%; specificity, 25%). CONCLUSIONS: The bacterial diarrhea prevalence is similar to that in other ambulatory studies, although the spectrum differs. Exclusion criteria for stool testing in diarrhea remain elusive. Studies to determine the etiology of unexplained diarrhea and cost-effective algorithms for diarrhea diagnosis, are needed.

A comparison of time to positive culture and time to clinical identification of serious bacterial infection in infants.

To compare the time to positive culture with the time to clinical detection of serious bacterial infection (SBI) in young infants, a retrospective case series of 949 infants age 0-60 days, who had a body fluid cultured in the emergency department or within 24 hours of admission was analyzed. Times to first report of positive culture and first clinical diagnosis of SBI were compared. Of 44 infants with positive cultures, 48% were clinically diagnosed with SBI at first evaluation. Of 21 infants with cultures reported positive after 24 hours, 14 were already diagnosed with SBI. Infections that altered therapy were identified after 24 and 36 hours in 4 infants and 1 infant, respectively. In infants with SBIs, the time to positive culture is longer than the time to identification of infection.

Shiga toxin-producing Escherichia coli in children with diarrhea: a prospective point-of-care study.

OBJECTIVE: To conduct a prospective cohort study to determine the frequency and characteristics of Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in children with diarrhea attending an emergency department and a private clinic in Seattle, Washington. METHODS: Between November 1998 and October 2001, 1851 stools were processed for STEC by sorbitol-MacConkey (SMAC) agar screening and a commercial Stx enzyme immunoassay (EIA). RESULTS: STEC belonging to serotypes O157:H7 (n = 28), O103:H2 (n = 4), O118:H16 (n = 2), O26:H11, O111:nonmotile, O111:H8, O121:H19, and O rough:H11 (n = 1 each) were recovered from 39 (2.1%) stools. EIA and SMAC agar detected 89% and 100% of the patients with E coli O157:H7, respectively. E coli O157:H7-infected patients had significantly higher frequencies of bloody stools, fecal leukocytes, and abdominal tenderness and shorter symptom duration. Hemolytic uremic syndrome developed in 5 (18%) and none of the children infected with E coli O157:H7 and non-O157:H7 STEC, respectively (P =.30). CONCLUSIONS: E coli O157:H7 is the predominant STEC in this population. Children infected with E coli O157:H7 have clinical presentations different from those whose stools contain non-O157:H7 STEC. Culture and Stx detection are needed to optimally detect STEC of all serotypes in stools. SMAC agar screening should not be replaced by EIA.