Nearly half of children with diarrhea at one emergency department over a 3-year period had stool samples containing pathogens, including Clostridium difficile and Shiga toxin-containing Escherichia coli, according to the results of a new study.
Dr. Eileen J. Klein of the University of Washington Children's Hospital and Regional Medical Center, Seattle, and her colleagues conducted a prospective cohort study in which they analyzed stool samples from 1,626 patients discharged with diarrhea, bloody diarrhea, or gastroenteritis at a Seattle emergency department during 1998–2001. Mean patient age was 2.5 years (Clin. Infect. Dis. 2006;43:807–13).
All stool samples underwent bacterial testing, 417 also underwent tests for viruses, and 656 were tested for parasites as well. A total of 372 samples underwent testing for all three types of pathogens and suspected pathogens C. difficile and Blastocystis hominis.
Of those 372 samples, 176 (47%) were positive for at least one pathogen. Of those tested for viral pathogens, 33% (138 of 417) were positive, and 7% of those tested for bacterial pathogens (118/1,626) were positive (of which 39 contained Shiga toxin-containing E. coli, 39 had salmonella, 25 had Campylobacter species, 14 had Shigella species, and 2 contained Yersinia enterocolitica).
For parasites, 7 (1%) of 656 tested samples were positive.
Moreover, 53 samples were positive for candidate pathogens; 7% (46 of 688) of those tested contained C. difficile, and 1% (7 of 656 tested) were positive for B. hominis.
The investigators also noted which seasons of the year had the greatest incidence of virus- or bacterium-containing stool samples.
For bacteria, winter had the smallest portion of positive samples, 4% vs. 14% for summer. However, the opposite was true for viruses; the summer months had 11% of positive specimens, vs. 53% for winter and 44% for spring.
Dr. Klein and her colleagues noted that they were “unable to develop a model substantially better than physician judgment to identify patients for whom a stool culture would yield positive results.”