1214. Evaluation of Two Multiplex Molecular GI Panels using Rectal Swab Specimens Versus Cary-Blair Stool in Pediatric Patients with Acute Gastroenteritis
Session: Poster Abstract Session: Clinical Infectious Diseases: Enteric Infections
Friday, October 28, 2016
Room: Poster Hall
  • IDSA poster FINAL2.pdf (832.2 kB)
  • Background:

    Surprisingly, patients presenting with acute gastroenteritis (AG) are often unable to provide a stool specimen at the time of their visit. Collection of a rectal swab, addresses an unmet clinical need to allow providers to obtain a specimen when evaluating the patient and when testing for GI pathogens is necessary. However, no GI multiplex molecular assays are currently FDA-cleared for use with a rectal swab collection. The purpose of this study was to evaluate two molecular multiplex GI assays, the Film Array Gastrointestinal Panel (FA) (Biofire Diagnostics) a 22 pathogen panel including viruses, bacteria, parasites and the BD MAX Enteric Bacterial Panel (MAX EBP) (Becton Dickinson) which detects Salmonella, Shigella, Campylobacter, and Shiga toxins (SSCST), using a rectal swab as the test sample.


    Pediatric patients presenting with AG were prospectively consented and enrolled to obtain both a rectal swab using the Fecal Swab (FS) (Copan Diagnostics) and a Cary-Blair (CB) stool. Enrollment is on-going. Both molecular panel assays were performed on all specimens submitted. Culture was done per provider request and/or when bacterial targets were detected by FA or MAX EBP. Percent agreement between specimen types and analytes for each system were compared. Discrepant results were resolved by positive culture and/or combination of molecular results.


    74 patients consented to date submitted both a rectal swab and CB stool specimen (paired specimens). 29 patients provided a rectal swab only. Positive specimens were 63.5% (47/74) and 6.7% (5/74) for paired and 72.4% (21/29) and 10.4% (3/29) for rectal swab only for FA and MAX EBP, respectively. Percent agreement between CB and FS was 48.6% for FA and 100% for MAX EBP. The most common pathogens detected with FA were viruses, C. difficile and EPEC. For 9 patients with 10 SSCST pathogens, MAX EBP and FA had 100% agreement. Culture missed 2 Shiga toxins and 1 Campylobacter.


    Both the Film Array and BD MAX GI pathogen assays showed excellent performance with rectal swabs using the FS collection system compared to CB stool. Use of a rectal swab guaranteed ability to obtain a specimen at the time of the patient visit.

    Kimberle Chapin, MD, Pathology, Rhode Island, Hasbro Medical Center, Providence, RI and Lindsay Leblanc, BS, Pathology, Rhode Island Hosp, providence, RI


    K. Chapin, Becton Dickenson: Grant Investigator and Scientific Advisor , Consulting fee , Research grant and Research support
    Biofire: Grant Investigator , Grant recipient , Research grant and Speaker honorarium

    L. Leblanc, None

    Findings in the abstracts are embargoed until 12:01 a.m. CDT, Wednesday Oct. 26th with the exception of research findings presented at the IDWeek press conferences.