Evaluation of the QIAstat-Dx® Gastrointestinal Panel 2 for detection of viral, bacterial and parasitic pathogens in fecal swab specimens

Abstract

This study evaluates the performance of the QIAstat-Dx® gastrointestinal panel 2 (GIP2) (Qiagen, Spain) for the gastrointestinal pathogens from Fecalswab® specimens (Copan, Italy). For most targets, specimens were tested initially on the Allplex^TM GI assays (Seegene, South Korea). For P. shigelloides, specimens were initially tested on BIOFIRE® GI Panel (BGIP) (bioMérieux, France). Two hundred fifty-nine specimens were tested on the GIP2 (69.5 % archived, 30.5 % prospective). Specimens with discordant results on Allplex^TM GI assays were tested on BGIP or Xpert® Norovirus (Cepheid, USA), while discordant results for P. shigelloides were tested by culture. Consensus results were obtained based on agreement of at least 2 of 3 tests. The percent positive and negative agreement (PPA, PNA) were calculated on a per target basis. Compared to consensus, GIP2 PPA was 95.02 % (95 % CI 91.78 – 97.25 %) and PNA was 99.98 % (95 % CI 99.90- 100.00 %). GIP2 performed well for bacterial and parasitic targets with PPA and PNA >97 %, however had a PPA of 88.3 % (95 % CI 80-81 – 93.61 %) and PNA of 100.0 % (95 % CI 99.75 – 100.00 %) for viral targets. When CT values were examined, QIAstat-dx GIP2 produce similar values to the Allplex^TM GI-viral assay. However, bacterial and parasitic targets on QIAstat-dx GIP2 trends towards lower CT values when compared to the Allplex^TM GI assays.