Performance evaluation of the QIAstat-Dx gastrointestinal panel 2 for the detection of <i>Clostridioides difficile</i> against multiple commercial assays

Acute gastroenteritis is caused by a variety of pathogens, including bacteria, viruses, and parasites, which may have overlapping clinical signs and symptoms. Community-acquired gastroenteritis is caused by various pathogens, while healthcare-associated gastroenteritis is caused by <i>Clostridioides difficile</i>. Current diagnostic approaches utilize <i>C. difficile</i> nucleic acid amplification tests (NAATs) alone or in combination with an enzyme immunoassay for <i>C. difficile</i> antigen and toxin. This study evaluates the analytical performance of <i>C. difficile</i> target detection from 290 clinical specimens using the QIAstat-Dx multiplex gastrointestinal panel (GIP) 2 compared with four commercially available NAATs (Cepheid Xpert <i>C. difficile</i>, BD MAX Cdiff, Verigene CDF, and BioFire GI panel) as well as the <i>C. difficile</i> immunoassay. The positive percent agreement (PPA) and negative percent agreement (NPA) were calculated for all assays in the study. All molecular assays demonstrated a PPA greater than 85%, and an NPA greater than 96% when compared to the other NAATs. The QIAstat-Dx GIP 2 performance was comparable to the other NAATs, demonstrating 95.0%, 88.5%, 98.1%, and 93.7% PPA and 98.2%, 96.9%, 96.6%, and 99.1% NPA compared to Cepheid Xpert <i>C. difficile</i>, BD MAX Cdiff, Verigene CDF, and BioFire GI panel, respectively. Overall, the QIAstat-Dx GIP 2 assay was accurate and comparable to other commercially available methods, and the short assay setup time offers an efficient laboratory stool testing workflow.IMPORTANCE<i>Clostridioides difficile</i> infection ranges from diarrhea to severe, life-threatening pseudomembranous colitis. Clinical criteria include three or more liquid stools in 24 h, while diagnostic testing includes nucleic acid tests alone or in combination with an enzyme immunoassay for <i>C. difficile</i> antigen and toxin. This study evaluates the analytical performance of <i>C. difficile</i> detection from clinical specimens using the QIAstat-Dx multiplex gastrointestinal panel compared with four commercial assays (Cepheid Xpert <i>C. difficile</i>, BD MAX Cdiff, Verigene CDF assays, and BioFire GI panel) and a <i>C. difficile</i> immunoassay. The BioFire GI panel had the highest positive percent agreement (90-100%), followed by the QIAstat-Dx (88-98%), BD MAX (87-98%), and the Xpert assays (86-96%). The QIAstat-Dx demonstrated high positive and negative agreement with all nucleic acid tests. The short assay setup time for the QIAstat-Dx GIP 2 also offers a streamlined testing workflow.