Performance of Stool Testing Recommendations for Acute Gastroenteritis when Used to Identify Children with Nine Potential Bacterial Enteropathogens

Background The ability to identify bacterial pathogens that necessitate specific clinical management or public health action in children with acute gastroenteritis is crucial to patient care and public health. However, existing stool testing guidelines offer inconsistent recommendations, and their performance characteristics are unknown. We evaluated six leading gastroenteritis guidelines (e.g. those of the Centers for Disease Control and Prevention and Infectious Disease Society of America) that recommend when to test children's stool for bacterial enteropathogens.
Methods Two emergency departments in Alberta, Canada, enrolled 2,447 children<18 years old who presented with ≥3 episodes of diarrhea and/or vomiting in a 24-hour period. All participants were tested for nine bacterial enteropathogens: Aeromonas, Campylobacter, Escherichia coli O157, other Shiga toxin-producing E. coli, enterotoxigenic E. coli, Salmonella, Shigella, Vibrio, and Yersinia. Patient data gathered at the index visit were used to determine if guidelines would recommend testing. Sensitivity and specificity to recommend testing for children with bacterial enteropathogens were calculated for each guideline.
Results Outcome data were available for 2,391 (97.7%) participants. Six percent (144/2391) of participants tested positive for a bacterial enteropathogen. Guideline sensitivity ranged from 25.8% [95% confidence interval (CI) 18.7%, 33.0%] to 66.9% (95% CI 59.3%, 74.6%) and varied for individual pathogens. Guideline specificity for all bacterial enteropathogens ranged from 63.6% (95% CI 61.6%, 65.6%) to 96.5% (95% CI 95.7%, 97.2%).
Conclusions No guideline provided optimally balanced performance. The most sensitive guidelines missed one-third of cases and would drastically increase testing volumes. The most specific guidelines missed almost 75% of cases.

as reported in: Clin Infect Dis. 2018 Dec 4 [Epub ahead of print]