title: How well does physician selection of microbiologic tests identify Clostridium difficile and other pathogens in paediatric diarrhoea? Insights using multiplex PCR-based detection.
abstract: The objective of this study was to compare the aetiologic yield of standard-of-care microbiologic testing ordered by physicians with that of a multiplex PCR platform. Stool specimens obtained from children and young adults with gastrointestinal illness were evaluated by standard laboratory methods and a developmental version of the FilmArray Gastrointestinal (GI) Diagnostic System (FilmArray GI Panel), a rapid multiplex PCR platform that detects 23 bacterial, viral and protozoal agents. Results were classified according to the microbiologic tests requested by the treating physician. A median of three (range 1-10) microbiologic tests were performed by the clinical laboratory during 378 unique diarrhoeal episodes. A potential aetiologic agent was identified in 46% of stool specimens by standard laboratory methods and in 65% of specimens tested using the FilmArray GI Panel (p < 0.001). For those patients who only had Clostridium difficile testing requested, an alternative pathogen was identified in 29% of cases with the FilmArray GI Panel. Notably, 11 (12%) cases of norovirus were identified among children who only had testing for Clostridium difficile ordered. Among those who had C. difficile testing ordered in combination with other tests, an additional pathogen was identified in 57% of stool specimens with the FilmArray GI Panel. For patients who had no C. difficile testing performed, the FilmArray GI Panel identified a pathogen in 63% of cases, including C. difficile in 8%. Physician-specified laboratory testing may miss important diarrhoeal pathogens. Additionally, standard laboratory testing is likely to underestimate co-infections with multiple infectious diarrhoeagenic agents.
authors.affiliation: Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, UT, USA. Electronic address: Chris.Stockmann@hsc.utah.edu.
authors.forename: C
authors.initials: C
authors.lastname: Stockmann
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: M
authors.initials: M
authors.lastname: Rogatcheva
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: B
authors.initials: B
authors.lastname: Harrel
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: M
authors.initials: M
authors.lastname: Vaughn
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: R
authors.initials: R
authors.lastname: Crisp
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: M
authors.initials: M
authors.lastname: Poritz
authors.affiliation: BioFire Diagnostics Inc., Salt Lake City, UT, USA.
authors.forename: S
authors.initials: S
authors.lastname: Thatcher
authors.affiliation: Primary Children's Hospital, Intermountain Healthcare, Salt Lake City, UT, USA.
authors.forename: E K
authors.initials: EK
authors.lastname: Korgenski
authors.affiliation: Primary Children's Hospital, Intermountain Healthcare, Salt Lake City, UT, USA.
authors.forename: T
authors.initials: T
authors.lastname: Barney
authors.affiliation: Primary Children's Hospital, Intermountain Healthcare, Salt Lake City, UT, USA; Department of Pathology, University of Utah Health Sciences Center, Salt Lake City, UT, USA.
authors.forename: J
authors.initials: J
authors.lastname: Daly
authors.affiliation: Department of Pediatrics, University of Utah Health Sciences Center, Salt Lake City, UT, USA.
authors.forename: A T
authors.initials: AT
authors.lastname: Pavia
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001419:Bacteria / Q000302:isolation & purification; D002648:Child; D002675:Child, Preschool; D003955:Diagnostic Tests, Routine / Q000379:methods*; D003967:Diarrhea / Q000175:diagnosis*; D005243:Feces / Q000382:microbiology* / Q000469:parasitology / Q000821:virology*; D005260:Female; D006302:Health Services Research; D006801:Humans; D007223:Infant; D008297:Male; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods*; D010271:Parasites / Q000302:isolation & purification; D010820:Physicians; D010818:Practice Patterns, Physicians'; D014780:Viruses / Q000302:isolation & purification; D055815:Young Adult
keywords: Acute gastroenteritis; Clostridium difficile; FilmArray; children; gastrointestinal illness